10508ad1fSJeremy Kerr /* 20508ad1fSJeremy Kerr * FSI core driver 30508ad1fSJeremy Kerr * 40508ad1fSJeremy Kerr * Copyright (C) IBM Corporation 2016 50508ad1fSJeremy Kerr * 60508ad1fSJeremy Kerr * This program is free software; you can redistribute it and/or modify 70508ad1fSJeremy Kerr * it under the terms of the GNU General Public License version 2 as 80508ad1fSJeremy Kerr * published by the Free Software Foundation. 90508ad1fSJeremy Kerr * 100508ad1fSJeremy Kerr * This program is distributed in the hope that it will be useful, 110508ad1fSJeremy Kerr * but WITHOUT ANY WARRANTY; without even the implied warranty of 120508ad1fSJeremy Kerr * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 130508ad1fSJeremy Kerr * GNU General Public License for more details. 140508ad1fSJeremy Kerr */ 150508ad1fSJeremy Kerr 162b545cd8SJeremy Kerr #include <linux/crc4.h> 170508ad1fSJeremy Kerr #include <linux/device.h> 180508ad1fSJeremy Kerr #include <linux/fsi.h> 1909aecfabSJeremy Kerr #include <linux/idr.h> 200508ad1fSJeremy Kerr #include <linux/module.h> 21f6a2f8ebSJeremy Kerr #include <linux/of.h> 222b545cd8SJeremy Kerr #include <linux/slab.h> 23f7ade2a6SJeremy Kerr #include <linux/bitops.h> 240508ad1fSJeremy Kerr 2509aecfabSJeremy Kerr #include "fsi-master.h" 2609aecfabSJeremy Kerr 2766433b05SJeremy Kerr #define CREATE_TRACE_POINTS 2866433b05SJeremy Kerr #include <trace/events/fsi.h> 2966433b05SJeremy Kerr 30f7ade2a6SJeremy Kerr #define FSI_SLAVE_CONF_NEXT_MASK GENMASK(31, 31) 31f7ade2a6SJeremy Kerr #define FSI_SLAVE_CONF_SLOTS_MASK GENMASK(23, 16) 32f7ade2a6SJeremy Kerr #define FSI_SLAVE_CONF_SLOTS_SHIFT 16 33f7ade2a6SJeremy Kerr #define FSI_SLAVE_CONF_VERSION_MASK GENMASK(15, 12) 34f7ade2a6SJeremy Kerr #define FSI_SLAVE_CONF_VERSION_SHIFT 12 35f7ade2a6SJeremy Kerr #define FSI_SLAVE_CONF_TYPE_MASK GENMASK(11, 4) 36f7ade2a6SJeremy Kerr #define FSI_SLAVE_CONF_TYPE_SHIFT 4 37f7ade2a6SJeremy Kerr #define FSI_SLAVE_CONF_CRC_SHIFT 4 38f7ade2a6SJeremy Kerr #define FSI_SLAVE_CONF_CRC_MASK GENMASK(3, 0) 39f7ade2a6SJeremy Kerr #define FSI_SLAVE_CONF_DATA_BITS 28 40f7ade2a6SJeremy Kerr 414efe37f4SJeremy Kerr #define FSI_PEEK_BASE 0x410 424efe37f4SJeremy Kerr 43f7ade2a6SJeremy Kerr static const int engine_page_size = 0x400; 44f7ade2a6SJeremy Kerr 452b37c3e2SChristopher Bostic #define FSI_SLAVE_BASE 0x800 462b37c3e2SChristopher Bostic 472b37c3e2SChristopher Bostic /* 482b37c3e2SChristopher Bostic * FSI slave engine control register offsets 492b37c3e2SChristopher Bostic */ 502b37c3e2SChristopher Bostic #define FSI_SMODE 0x0 /* R/W: Mode register */ 511fa847d7SJeremy Kerr #define FSI_SISC 0x8 /* R/W: Interrupt condition */ 521fa847d7SJeremy Kerr #define FSI_SSTAT 0x14 /* R : Slave status */ 534af889b0SJeremy Kerr #define FSI_LLMODE 0x100 /* R/W: Link layer mode register */ 542b37c3e2SChristopher Bostic 552b37c3e2SChristopher Bostic /* 562b37c3e2SChristopher Bostic * SMODE fields 572b37c3e2SChristopher Bostic */ 582b37c3e2SChristopher Bostic #define FSI_SMODE_WSC 0x80000000 /* Warm start done */ 592b37c3e2SChristopher Bostic #define FSI_SMODE_ECRC 0x20000000 /* Hw CRC check */ 602b37c3e2SChristopher Bostic #define FSI_SMODE_SID_SHIFT 24 /* ID shift */ 612b37c3e2SChristopher Bostic #define FSI_SMODE_SID_MASK 3 /* ID Mask */ 622b37c3e2SChristopher Bostic #define FSI_SMODE_ED_SHIFT 20 /* Echo delay shift */ 632b37c3e2SChristopher Bostic #define FSI_SMODE_ED_MASK 0xf /* Echo delay mask */ 642b37c3e2SChristopher Bostic #define FSI_SMODE_SD_SHIFT 16 /* Send delay shift */ 652b37c3e2SChristopher Bostic #define FSI_SMODE_SD_MASK 0xf /* Send delay mask */ 662b37c3e2SChristopher Bostic #define FSI_SMODE_LBCRR_SHIFT 8 /* Clk ratio shift */ 672b37c3e2SChristopher Bostic #define FSI_SMODE_LBCRR_MASK 0xf /* Clk ratio mask */ 682b37c3e2SChristopher Bostic 694af889b0SJeremy Kerr /* 704af889b0SJeremy Kerr * LLMODE fields 714af889b0SJeremy Kerr */ 724af889b0SJeremy Kerr #define FSI_LLMODE_ASYNC 0x1 734af889b0SJeremy Kerr 742b545cd8SJeremy Kerr #define FSI_SLAVE_SIZE_23b 0x800000 752b545cd8SJeremy Kerr 7609aecfabSJeremy Kerr static DEFINE_IDA(master_ida); 7709aecfabSJeremy Kerr 78faf0b116SJeremy Kerr struct fsi_slave { 79faf0b116SJeremy Kerr struct device dev; 80faf0b116SJeremy Kerr struct fsi_master *master; 81faf0b116SJeremy Kerr int id; 82faf0b116SJeremy Kerr int link; 830a213777SBenjamin Herrenschmidt int chip_id; 84faf0b116SJeremy Kerr uint32_t size; /* size of slave address space */ 85a2e7da86SBenjamin Herrenschmidt u8 t_send_delay; 86a2e7da86SBenjamin Herrenschmidt u8 t_echo_delay; 87faf0b116SJeremy Kerr }; 88faf0b116SJeremy Kerr 89cd0fdb5cSChristopher Bostic #define to_fsi_master(d) container_of(d, struct fsi_master, dev) 90faf0b116SJeremy Kerr #define to_fsi_slave(d) container_of(d, struct fsi_slave, dev) 91faf0b116SJeremy Kerr 921fa847d7SJeremy Kerr static const int slave_retries = 2; 931fa847d7SJeremy Kerr static int discard_errors; 941fa847d7SJeremy Kerr 95014c2abcSJeremy Kerr static int fsi_master_read(struct fsi_master *master, int link, 96014c2abcSJeremy Kerr uint8_t slave_id, uint32_t addr, void *val, size_t size); 97014c2abcSJeremy Kerr static int fsi_master_write(struct fsi_master *master, int link, 98014c2abcSJeremy Kerr uint8_t slave_id, uint32_t addr, const void *val, size_t size); 991fa847d7SJeremy Kerr static int fsi_master_break(struct fsi_master *master, int link); 100014c2abcSJeremy Kerr 1014efe37f4SJeremy Kerr /* 1024efe37f4SJeremy Kerr * fsi_device_read() / fsi_device_write() / fsi_device_peek() 1034efe37f4SJeremy Kerr * 1044efe37f4SJeremy Kerr * FSI endpoint-device support 1054efe37f4SJeremy Kerr * 1064efe37f4SJeremy Kerr * Read / write / peek accessors for a client 1074efe37f4SJeremy Kerr * 1084efe37f4SJeremy Kerr * Parameters: 1094efe37f4SJeremy Kerr * dev: Structure passed to FSI client device drivers on probe(). 1104efe37f4SJeremy Kerr * addr: FSI address of given device. Client should pass in its base address 1114efe37f4SJeremy Kerr * plus desired offset to access its register space. 1124efe37f4SJeremy Kerr * val: For read/peek this is the value read at the specified address. For 1134efe37f4SJeremy Kerr * write this is value to write to the specified address. 1144efe37f4SJeremy Kerr * The data in val must be FSI bus endian (big endian). 1154efe37f4SJeremy Kerr * size: Size in bytes of the operation. Sizes supported are 1, 2 and 4 bytes. 1164efe37f4SJeremy Kerr * Addresses must be aligned on size boundaries or an error will result. 1174efe37f4SJeremy Kerr */ 1184efe37f4SJeremy Kerr int fsi_device_read(struct fsi_device *dev, uint32_t addr, void *val, 1194efe37f4SJeremy Kerr size_t size) 1204efe37f4SJeremy Kerr { 1214efe37f4SJeremy Kerr if (addr > dev->size || size > dev->size || addr > dev->size - size) 1224efe37f4SJeremy Kerr return -EINVAL; 1234efe37f4SJeremy Kerr 1244efe37f4SJeremy Kerr return fsi_slave_read(dev->slave, dev->addr + addr, val, size); 1254efe37f4SJeremy Kerr } 1264efe37f4SJeremy Kerr EXPORT_SYMBOL_GPL(fsi_device_read); 1274efe37f4SJeremy Kerr 1284efe37f4SJeremy Kerr int fsi_device_write(struct fsi_device *dev, uint32_t addr, const void *val, 1294efe37f4SJeremy Kerr size_t size) 1304efe37f4SJeremy Kerr { 1314efe37f4SJeremy Kerr if (addr > dev->size || size > dev->size || addr > dev->size - size) 1324efe37f4SJeremy Kerr return -EINVAL; 1334efe37f4SJeremy Kerr 1344efe37f4SJeremy Kerr return fsi_slave_write(dev->slave, dev->addr + addr, val, size); 1354efe37f4SJeremy Kerr } 1364efe37f4SJeremy Kerr EXPORT_SYMBOL_GPL(fsi_device_write); 1374efe37f4SJeremy Kerr 1384efe37f4SJeremy Kerr int fsi_device_peek(struct fsi_device *dev, void *val) 1394efe37f4SJeremy Kerr { 1404efe37f4SJeremy Kerr uint32_t addr = FSI_PEEK_BASE + ((dev->unit - 2) * sizeof(uint32_t)); 1414efe37f4SJeremy Kerr 1424efe37f4SJeremy Kerr return fsi_slave_read(dev->slave, addr, val, sizeof(uint32_t)); 1434efe37f4SJeremy Kerr } 144f7ade2a6SJeremy Kerr 145f7ade2a6SJeremy Kerr static void fsi_device_release(struct device *_device) 146f7ade2a6SJeremy Kerr { 147f7ade2a6SJeremy Kerr struct fsi_device *device = to_fsi_dev(_device); 148f7ade2a6SJeremy Kerr 149f6a2f8ebSJeremy Kerr of_node_put(device->dev.of_node); 150f7ade2a6SJeremy Kerr kfree(device); 151f7ade2a6SJeremy Kerr } 152f7ade2a6SJeremy Kerr 153f7ade2a6SJeremy Kerr static struct fsi_device *fsi_create_device(struct fsi_slave *slave) 154f7ade2a6SJeremy Kerr { 155f7ade2a6SJeremy Kerr struct fsi_device *dev; 156f7ade2a6SJeremy Kerr 157f7ade2a6SJeremy Kerr dev = kzalloc(sizeof(*dev), GFP_KERNEL); 158f7ade2a6SJeremy Kerr if (!dev) 159f7ade2a6SJeremy Kerr return NULL; 160f7ade2a6SJeremy Kerr 161f7ade2a6SJeremy Kerr dev->dev.parent = &slave->dev; 162f7ade2a6SJeremy Kerr dev->dev.bus = &fsi_bus_type; 163f7ade2a6SJeremy Kerr dev->dev.release = fsi_device_release; 164f7ade2a6SJeremy Kerr 165f7ade2a6SJeremy Kerr return dev; 166f7ade2a6SJeremy Kerr } 167f7ade2a6SJeremy Kerr 168414c1026SJeremy Kerr /* FSI slave support */ 169014c2abcSJeremy Kerr static int fsi_slave_calc_addr(struct fsi_slave *slave, uint32_t *addrp, 170014c2abcSJeremy Kerr uint8_t *idp) 171014c2abcSJeremy Kerr { 172014c2abcSJeremy Kerr uint32_t addr = *addrp; 173014c2abcSJeremy Kerr uint8_t id = *idp; 174014c2abcSJeremy Kerr 175014c2abcSJeremy Kerr if (addr > slave->size) 176014c2abcSJeremy Kerr return -EINVAL; 177014c2abcSJeremy Kerr 178014c2abcSJeremy Kerr /* For 23 bit addressing, we encode the extra two bits in the slave 179014c2abcSJeremy Kerr * id (and the slave's actual ID needs to be 0). 180014c2abcSJeremy Kerr */ 181014c2abcSJeremy Kerr if (addr > 0x1fffff) { 182014c2abcSJeremy Kerr if (slave->id != 0) 183014c2abcSJeremy Kerr return -EINVAL; 184014c2abcSJeremy Kerr id = (addr >> 21) & 0x3; 185014c2abcSJeremy Kerr addr &= 0x1fffff; 186014c2abcSJeremy Kerr } 187014c2abcSJeremy Kerr 188014c2abcSJeremy Kerr *addrp = addr; 189014c2abcSJeremy Kerr *idp = id; 190014c2abcSJeremy Kerr return 0; 191014c2abcSJeremy Kerr } 192014c2abcSJeremy Kerr 193ed50a089SColin Ian King static int fsi_slave_report_and_clear_errors(struct fsi_slave *slave) 1941fa847d7SJeremy Kerr { 1951fa847d7SJeremy Kerr struct fsi_master *master = slave->master; 19611454d6dSJoel Stanley __be32 irq, stat; 1971fa847d7SJeremy Kerr int rc, link; 1981fa847d7SJeremy Kerr uint8_t id; 1991fa847d7SJeremy Kerr 2001fa847d7SJeremy Kerr link = slave->link; 2011fa847d7SJeremy Kerr id = slave->id; 2021fa847d7SJeremy Kerr 2031fa847d7SJeremy Kerr rc = fsi_master_read(master, link, id, FSI_SLAVE_BASE + FSI_SISC, 2041fa847d7SJeremy Kerr &irq, sizeof(irq)); 2051fa847d7SJeremy Kerr if (rc) 2061fa847d7SJeremy Kerr return rc; 2071fa847d7SJeremy Kerr 2081fa847d7SJeremy Kerr rc = fsi_master_read(master, link, id, FSI_SLAVE_BASE + FSI_SSTAT, 2091fa847d7SJeremy Kerr &stat, sizeof(stat)); 2101fa847d7SJeremy Kerr if (rc) 2111fa847d7SJeremy Kerr return rc; 2121fa847d7SJeremy Kerr 213638bd9acSChristopher Bostic dev_dbg(&slave->dev, "status: 0x%08x, sisc: 0x%08x\n", 2141fa847d7SJeremy Kerr be32_to_cpu(stat), be32_to_cpu(irq)); 2151fa847d7SJeremy Kerr 2161fa847d7SJeremy Kerr /* clear interrupts */ 2171fa847d7SJeremy Kerr return fsi_master_write(master, link, id, FSI_SLAVE_BASE + FSI_SISC, 2181fa847d7SJeremy Kerr &irq, sizeof(irq)); 2191fa847d7SJeremy Kerr } 2201fa847d7SJeremy Kerr 221935f9636SBenjamin Herrenschmidt /* Encode slave local bus echo delay */ 222935f9636SBenjamin Herrenschmidt static inline uint32_t fsi_smode_echodly(int x) 223935f9636SBenjamin Herrenschmidt { 224935f9636SBenjamin Herrenschmidt return (x & FSI_SMODE_ED_MASK) << FSI_SMODE_ED_SHIFT; 225935f9636SBenjamin Herrenschmidt } 226935f9636SBenjamin Herrenschmidt 227935f9636SBenjamin Herrenschmidt /* Encode slave local bus send delay */ 228935f9636SBenjamin Herrenschmidt static inline uint32_t fsi_smode_senddly(int x) 229935f9636SBenjamin Herrenschmidt { 230935f9636SBenjamin Herrenschmidt return (x & FSI_SMODE_SD_MASK) << FSI_SMODE_SD_SHIFT; 231935f9636SBenjamin Herrenschmidt } 232935f9636SBenjamin Herrenschmidt 233935f9636SBenjamin Herrenschmidt /* Encode slave local bus clock rate ratio */ 234935f9636SBenjamin Herrenschmidt static inline uint32_t fsi_smode_lbcrr(int x) 235935f9636SBenjamin Herrenschmidt { 236935f9636SBenjamin Herrenschmidt return (x & FSI_SMODE_LBCRR_MASK) << FSI_SMODE_LBCRR_SHIFT; 237935f9636SBenjamin Herrenschmidt } 238935f9636SBenjamin Herrenschmidt 239935f9636SBenjamin Herrenschmidt /* Encode slave ID */ 240935f9636SBenjamin Herrenschmidt static inline uint32_t fsi_smode_sid(int x) 241935f9636SBenjamin Herrenschmidt { 242935f9636SBenjamin Herrenschmidt return (x & FSI_SMODE_SID_MASK) << FSI_SMODE_SID_SHIFT; 243935f9636SBenjamin Herrenschmidt } 244935f9636SBenjamin Herrenschmidt 245a2e7da86SBenjamin Herrenschmidt static uint32_t fsi_slave_smode(int id, u8 t_senddly, u8 t_echodly) 246935f9636SBenjamin Herrenschmidt { 247935f9636SBenjamin Herrenschmidt return FSI_SMODE_WSC | FSI_SMODE_ECRC 248935f9636SBenjamin Herrenschmidt | fsi_smode_sid(id) 249a2e7da86SBenjamin Herrenschmidt | fsi_smode_echodly(t_echodly - 1) | fsi_smode_senddly(t_senddly - 1) 250935f9636SBenjamin Herrenschmidt | fsi_smode_lbcrr(0x8); 251935f9636SBenjamin Herrenschmidt } 252935f9636SBenjamin Herrenschmidt 253a2e7da86SBenjamin Herrenschmidt static int fsi_slave_set_smode(struct fsi_slave *slave) 254935f9636SBenjamin Herrenschmidt { 255935f9636SBenjamin Herrenschmidt uint32_t smode; 256935f9636SBenjamin Herrenschmidt __be32 data; 257935f9636SBenjamin Herrenschmidt 258935f9636SBenjamin Herrenschmidt /* set our smode register with the slave ID field to 0; this enables 259935f9636SBenjamin Herrenschmidt * extended slave addressing 260935f9636SBenjamin Herrenschmidt */ 261a2e7da86SBenjamin Herrenschmidt smode = fsi_slave_smode(slave->id, slave->t_send_delay, slave->t_echo_delay); 262935f9636SBenjamin Herrenschmidt data = cpu_to_be32(smode); 263935f9636SBenjamin Herrenschmidt 264a2e7da86SBenjamin Herrenschmidt return fsi_master_write(slave->master, slave->link, slave->id, 265a2e7da86SBenjamin Herrenschmidt FSI_SLAVE_BASE + FSI_SMODE, 266935f9636SBenjamin Herrenschmidt &data, sizeof(data)); 267935f9636SBenjamin Herrenschmidt } 2681fa847d7SJeremy Kerr 269ed50a089SColin Ian King static int fsi_slave_handle_error(struct fsi_slave *slave, bool write, 270ed50a089SColin Ian King uint32_t addr, size_t size) 2711fa847d7SJeremy Kerr { 2721fa847d7SJeremy Kerr struct fsi_master *master = slave->master; 2731fa847d7SJeremy Kerr int rc, link; 2741fa847d7SJeremy Kerr uint32_t reg; 275a2e7da86SBenjamin Herrenschmidt uint8_t id, send_delay, echo_delay; 2761fa847d7SJeremy Kerr 2771fa847d7SJeremy Kerr if (discard_errors) 2781fa847d7SJeremy Kerr return -1; 2791fa847d7SJeremy Kerr 2801fa847d7SJeremy Kerr link = slave->link; 2811fa847d7SJeremy Kerr id = slave->id; 2821fa847d7SJeremy Kerr 2831fa847d7SJeremy Kerr dev_dbg(&slave->dev, "handling error on %s to 0x%08x[%zd]", 2841fa847d7SJeremy Kerr write ? "write" : "read", addr, size); 2851fa847d7SJeremy Kerr 2861fa847d7SJeremy Kerr /* try a simple clear of error conditions, which may fail if we've lost 2871fa847d7SJeremy Kerr * communication with the slave 2881fa847d7SJeremy Kerr */ 2891fa847d7SJeremy Kerr rc = fsi_slave_report_and_clear_errors(slave); 2901fa847d7SJeremy Kerr if (!rc) 2911fa847d7SJeremy Kerr return 0; 2921fa847d7SJeremy Kerr 2931fa847d7SJeremy Kerr /* send a TERM and retry */ 2941fa847d7SJeremy Kerr if (master->term) { 2951fa847d7SJeremy Kerr rc = master->term(master, link, id); 2961fa847d7SJeremy Kerr if (!rc) { 2971fa847d7SJeremy Kerr rc = fsi_master_read(master, link, id, 0, 2981fa847d7SJeremy Kerr ®, sizeof(reg)); 2991fa847d7SJeremy Kerr if (!rc) 3001fa847d7SJeremy Kerr rc = fsi_slave_report_and_clear_errors(slave); 3011fa847d7SJeremy Kerr if (!rc) 3021fa847d7SJeremy Kerr return 0; 3031fa847d7SJeremy Kerr } 3041fa847d7SJeremy Kerr } 3051fa847d7SJeremy Kerr 306a2e7da86SBenjamin Herrenschmidt send_delay = slave->t_send_delay; 307a2e7da86SBenjamin Herrenschmidt echo_delay = slave->t_echo_delay; 308a2e7da86SBenjamin Herrenschmidt 3091fa847d7SJeremy Kerr /* getting serious, reset the slave via BREAK */ 3101fa847d7SJeremy Kerr rc = fsi_master_break(master, link); 3111fa847d7SJeremy Kerr if (rc) 3121fa847d7SJeremy Kerr return rc; 3131fa847d7SJeremy Kerr 314a2e7da86SBenjamin Herrenschmidt slave->t_send_delay = send_delay; 315a2e7da86SBenjamin Herrenschmidt slave->t_echo_delay = echo_delay; 316a2e7da86SBenjamin Herrenschmidt 317a2e7da86SBenjamin Herrenschmidt rc = fsi_slave_set_smode(slave); 3181fa847d7SJeremy Kerr if (rc) 3191fa847d7SJeremy Kerr return rc; 3201fa847d7SJeremy Kerr 321a2e7da86SBenjamin Herrenschmidt if (master->link_config) 322a2e7da86SBenjamin Herrenschmidt master->link_config(master, link, 323a2e7da86SBenjamin Herrenschmidt slave->t_send_delay, 324a2e7da86SBenjamin Herrenschmidt slave->t_echo_delay); 325a2e7da86SBenjamin Herrenschmidt 3261fa847d7SJeremy Kerr return fsi_slave_report_and_clear_errors(slave); 3271fa847d7SJeremy Kerr } 3281fa847d7SJeremy Kerr 329da36cadfSJeremy Kerr int fsi_slave_read(struct fsi_slave *slave, uint32_t addr, 330014c2abcSJeremy Kerr void *val, size_t size) 331014c2abcSJeremy Kerr { 332014c2abcSJeremy Kerr uint8_t id = slave->id; 3331fa847d7SJeremy Kerr int rc, err_rc, i; 334014c2abcSJeremy Kerr 335014c2abcSJeremy Kerr rc = fsi_slave_calc_addr(slave, &addr, &id); 336014c2abcSJeremy Kerr if (rc) 337014c2abcSJeremy Kerr return rc; 338014c2abcSJeremy Kerr 3391fa847d7SJeremy Kerr for (i = 0; i < slave_retries; i++) { 3401fa847d7SJeremy Kerr rc = fsi_master_read(slave->master, slave->link, 3411fa847d7SJeremy Kerr id, addr, val, size); 3421fa847d7SJeremy Kerr if (!rc) 3431fa847d7SJeremy Kerr break; 3441fa847d7SJeremy Kerr 3451fa847d7SJeremy Kerr err_rc = fsi_slave_handle_error(slave, false, addr, size); 3461fa847d7SJeremy Kerr if (err_rc) 3471fa847d7SJeremy Kerr break; 3481fa847d7SJeremy Kerr } 3491fa847d7SJeremy Kerr 3501fa847d7SJeremy Kerr return rc; 351014c2abcSJeremy Kerr } 352da36cadfSJeremy Kerr EXPORT_SYMBOL_GPL(fsi_slave_read); 353014c2abcSJeremy Kerr 354da36cadfSJeremy Kerr int fsi_slave_write(struct fsi_slave *slave, uint32_t addr, 355014c2abcSJeremy Kerr const void *val, size_t size) 356014c2abcSJeremy Kerr { 357014c2abcSJeremy Kerr uint8_t id = slave->id; 3581fa847d7SJeremy Kerr int rc, err_rc, i; 359014c2abcSJeremy Kerr 360014c2abcSJeremy Kerr rc = fsi_slave_calc_addr(slave, &addr, &id); 361014c2abcSJeremy Kerr if (rc) 362014c2abcSJeremy Kerr return rc; 363014c2abcSJeremy Kerr 3641fa847d7SJeremy Kerr for (i = 0; i < slave_retries; i++) { 3651fa847d7SJeremy Kerr rc = fsi_master_write(slave->master, slave->link, 3661fa847d7SJeremy Kerr id, addr, val, size); 3671fa847d7SJeremy Kerr if (!rc) 3681fa847d7SJeremy Kerr break; 3691fa847d7SJeremy Kerr 3701fa847d7SJeremy Kerr err_rc = fsi_slave_handle_error(slave, true, addr, size); 3711fa847d7SJeremy Kerr if (err_rc) 3721fa847d7SJeremy Kerr break; 3731fa847d7SJeremy Kerr } 3741fa847d7SJeremy Kerr 3751fa847d7SJeremy Kerr return rc; 376014c2abcSJeremy Kerr } 377da36cadfSJeremy Kerr EXPORT_SYMBOL_GPL(fsi_slave_write); 378da36cadfSJeremy Kerr 379da36cadfSJeremy Kerr extern int fsi_slave_claim_range(struct fsi_slave *slave, 380da36cadfSJeremy Kerr uint32_t addr, uint32_t size) 381da36cadfSJeremy Kerr { 382da36cadfSJeremy Kerr if (addr + size < addr) 383da36cadfSJeremy Kerr return -EINVAL; 384da36cadfSJeremy Kerr 385da36cadfSJeremy Kerr if (addr + size > slave->size) 386da36cadfSJeremy Kerr return -EINVAL; 387da36cadfSJeremy Kerr 388da36cadfSJeremy Kerr /* todo: check for overlapping claims */ 389da36cadfSJeremy Kerr return 0; 390da36cadfSJeremy Kerr } 391da36cadfSJeremy Kerr EXPORT_SYMBOL_GPL(fsi_slave_claim_range); 392da36cadfSJeremy Kerr 393da36cadfSJeremy Kerr extern void fsi_slave_release_range(struct fsi_slave *slave, 394da36cadfSJeremy Kerr uint32_t addr, uint32_t size) 395da36cadfSJeremy Kerr { 396da36cadfSJeremy Kerr } 397da36cadfSJeremy Kerr EXPORT_SYMBOL_GPL(fsi_slave_release_range); 398014c2abcSJeremy Kerr 399f6a2f8ebSJeremy Kerr static bool fsi_device_node_matches(struct device *dev, struct device_node *np, 400f6a2f8ebSJeremy Kerr uint32_t addr, uint32_t size) 401f6a2f8ebSJeremy Kerr { 402f6a2f8ebSJeremy Kerr unsigned int len, na, ns; 403f6a2f8ebSJeremy Kerr const __be32 *prop; 404f6a2f8ebSJeremy Kerr uint32_t psize; 405f6a2f8ebSJeremy Kerr 406f6a2f8ebSJeremy Kerr na = of_n_addr_cells(np); 407f6a2f8ebSJeremy Kerr ns = of_n_size_cells(np); 408f6a2f8ebSJeremy Kerr 409f6a2f8ebSJeremy Kerr if (na != 1 || ns != 1) 410f6a2f8ebSJeremy Kerr return false; 411f6a2f8ebSJeremy Kerr 412f6a2f8ebSJeremy Kerr prop = of_get_property(np, "reg", &len); 413f6a2f8ebSJeremy Kerr if (!prop || len != 8) 414f6a2f8ebSJeremy Kerr return false; 415f6a2f8ebSJeremy Kerr 416f6a2f8ebSJeremy Kerr if (of_read_number(prop, 1) != addr) 417f6a2f8ebSJeremy Kerr return false; 418f6a2f8ebSJeremy Kerr 419f6a2f8ebSJeremy Kerr psize = of_read_number(prop + 1, 1); 420f6a2f8ebSJeremy Kerr if (psize != size) { 421f6a2f8ebSJeremy Kerr dev_warn(dev, 422f6a2f8ebSJeremy Kerr "node %s matches probed address, but not size (got 0x%x, expected 0x%x)", 423f6a2f8ebSJeremy Kerr of_node_full_name(np), psize, size); 424f6a2f8ebSJeremy Kerr } 425f6a2f8ebSJeremy Kerr 426f6a2f8ebSJeremy Kerr return true; 427f6a2f8ebSJeremy Kerr } 428f6a2f8ebSJeremy Kerr 429f6a2f8ebSJeremy Kerr /* Find a matching node for the slave engine at @address, using @size bytes 430f6a2f8ebSJeremy Kerr * of space. Returns NULL if not found, or a matching node with refcount 431f6a2f8ebSJeremy Kerr * already incremented. 432f6a2f8ebSJeremy Kerr */ 433f6a2f8ebSJeremy Kerr static struct device_node *fsi_device_find_of_node(struct fsi_device *dev) 434f6a2f8ebSJeremy Kerr { 435f6a2f8ebSJeremy Kerr struct device_node *parent, *np; 436f6a2f8ebSJeremy Kerr 437f6a2f8ebSJeremy Kerr parent = dev_of_node(&dev->slave->dev); 438f6a2f8ebSJeremy Kerr if (!parent) 439f6a2f8ebSJeremy Kerr return NULL; 440f6a2f8ebSJeremy Kerr 441f6a2f8ebSJeremy Kerr for_each_child_of_node(parent, np) { 442f6a2f8ebSJeremy Kerr if (fsi_device_node_matches(&dev->dev, np, 443f6a2f8ebSJeremy Kerr dev->addr, dev->size)) 444f6a2f8ebSJeremy Kerr return np; 445f6a2f8ebSJeremy Kerr } 446f6a2f8ebSJeremy Kerr 447f6a2f8ebSJeremy Kerr return NULL; 448f6a2f8ebSJeremy Kerr } 449f6a2f8ebSJeremy Kerr 450f7ade2a6SJeremy Kerr static int fsi_slave_scan(struct fsi_slave *slave) 451f7ade2a6SJeremy Kerr { 452f7ade2a6SJeremy Kerr uint32_t engine_addr; 453f7ade2a6SJeremy Kerr int rc, i; 454f7ade2a6SJeremy Kerr 455f7ade2a6SJeremy Kerr /* 456f7ade2a6SJeremy Kerr * scan engines 457f7ade2a6SJeremy Kerr * 458f7ade2a6SJeremy Kerr * We keep the peek mode and slave engines for the core; so start 459f7ade2a6SJeremy Kerr * at the third slot in the configuration table. We also need to 460f7ade2a6SJeremy Kerr * skip the chip ID entry at the start of the address space. 461f7ade2a6SJeremy Kerr */ 462f7ade2a6SJeremy Kerr engine_addr = engine_page_size * 3; 463f7ade2a6SJeremy Kerr for (i = 2; i < engine_page_size / sizeof(uint32_t); i++) { 464f7ade2a6SJeremy Kerr uint8_t slots, version, type, crc; 465f7ade2a6SJeremy Kerr struct fsi_device *dev; 46611454d6dSJoel Stanley uint32_t conf; 46711454d6dSJoel Stanley __be32 data; 468f7ade2a6SJeremy Kerr 46911454d6dSJoel Stanley rc = fsi_slave_read(slave, (i + 1) * sizeof(data), 47011454d6dSJoel Stanley &data, sizeof(data)); 471f7ade2a6SJeremy Kerr if (rc) { 472f7ade2a6SJeremy Kerr dev_warn(&slave->dev, 473f7ade2a6SJeremy Kerr "error reading slave registers\n"); 474f7ade2a6SJeremy Kerr return -1; 475f7ade2a6SJeremy Kerr } 47611454d6dSJoel Stanley conf = be32_to_cpu(data); 477f7ade2a6SJeremy Kerr 478f7ade2a6SJeremy Kerr crc = crc4(0, conf, 32); 479f7ade2a6SJeremy Kerr if (crc) { 480f7ade2a6SJeremy Kerr dev_warn(&slave->dev, 481f7ade2a6SJeremy Kerr "crc error in slave register at 0x%04x\n", 482f7ade2a6SJeremy Kerr i); 483f7ade2a6SJeremy Kerr return -1; 484f7ade2a6SJeremy Kerr } 485f7ade2a6SJeremy Kerr 486f7ade2a6SJeremy Kerr slots = (conf & FSI_SLAVE_CONF_SLOTS_MASK) 487f7ade2a6SJeremy Kerr >> FSI_SLAVE_CONF_SLOTS_SHIFT; 488f7ade2a6SJeremy Kerr version = (conf & FSI_SLAVE_CONF_VERSION_MASK) 489f7ade2a6SJeremy Kerr >> FSI_SLAVE_CONF_VERSION_SHIFT; 490f7ade2a6SJeremy Kerr type = (conf & FSI_SLAVE_CONF_TYPE_MASK) 491f7ade2a6SJeremy Kerr >> FSI_SLAVE_CONF_TYPE_SHIFT; 492f7ade2a6SJeremy Kerr 493f7ade2a6SJeremy Kerr /* 494f7ade2a6SJeremy Kerr * Unused address areas are marked by a zero type value; this 495f7ade2a6SJeremy Kerr * skips the defined address areas 496f7ade2a6SJeremy Kerr */ 497f7ade2a6SJeremy Kerr if (type != 0 && slots != 0) { 498f7ade2a6SJeremy Kerr 499f7ade2a6SJeremy Kerr /* create device */ 500f7ade2a6SJeremy Kerr dev = fsi_create_device(slave); 501f7ade2a6SJeremy Kerr if (!dev) 502f7ade2a6SJeremy Kerr return -ENOMEM; 503f7ade2a6SJeremy Kerr 504f7ade2a6SJeremy Kerr dev->slave = slave; 505f7ade2a6SJeremy Kerr dev->engine_type = type; 506f7ade2a6SJeremy Kerr dev->version = version; 507f7ade2a6SJeremy Kerr dev->unit = i; 508f7ade2a6SJeremy Kerr dev->addr = engine_addr; 509f7ade2a6SJeremy Kerr dev->size = slots * engine_page_size; 510f7ade2a6SJeremy Kerr 511f7ade2a6SJeremy Kerr dev_dbg(&slave->dev, 512f7ade2a6SJeremy Kerr "engine[%i]: type %x, version %x, addr %x size %x\n", 513f7ade2a6SJeremy Kerr dev->unit, dev->engine_type, version, 514f7ade2a6SJeremy Kerr dev->addr, dev->size); 515f7ade2a6SJeremy Kerr 516f7ade2a6SJeremy Kerr dev_set_name(&dev->dev, "%02x:%02x:%02x:%02x", 517f7ade2a6SJeremy Kerr slave->master->idx, slave->link, 518f7ade2a6SJeremy Kerr slave->id, i - 2); 519f6a2f8ebSJeremy Kerr dev->dev.of_node = fsi_device_find_of_node(dev); 520f7ade2a6SJeremy Kerr 521f7ade2a6SJeremy Kerr rc = device_register(&dev->dev); 522f7ade2a6SJeremy Kerr if (rc) { 523f7ade2a6SJeremy Kerr dev_warn(&slave->dev, "add failed: %d\n", rc); 524f7ade2a6SJeremy Kerr put_device(&dev->dev); 525f7ade2a6SJeremy Kerr } 526f7ade2a6SJeremy Kerr } 527f7ade2a6SJeremy Kerr 528f7ade2a6SJeremy Kerr engine_addr += slots * engine_page_size; 529f7ade2a6SJeremy Kerr 530f7ade2a6SJeremy Kerr if (!(conf & FSI_SLAVE_CONF_NEXT_MASK)) 531f7ade2a6SJeremy Kerr break; 532f7ade2a6SJeremy Kerr } 533f7ade2a6SJeremy Kerr 534f7ade2a6SJeremy Kerr return 0; 535f7ade2a6SJeremy Kerr } 536f7ade2a6SJeremy Kerr 537125739cbSJeremy Kerr static ssize_t fsi_slave_sysfs_raw_read(struct file *file, 538125739cbSJeremy Kerr struct kobject *kobj, struct bin_attribute *attr, char *buf, 539125739cbSJeremy Kerr loff_t off, size_t count) 540125739cbSJeremy Kerr { 541125739cbSJeremy Kerr struct fsi_slave *slave = to_fsi_slave(kobj_to_dev(kobj)); 542125739cbSJeremy Kerr size_t total_len, read_len; 543125739cbSJeremy Kerr int rc; 544125739cbSJeremy Kerr 545125739cbSJeremy Kerr if (off < 0) 546125739cbSJeremy Kerr return -EINVAL; 547125739cbSJeremy Kerr 548125739cbSJeremy Kerr if (off > 0xffffffff || count > 0xffffffff || off + count > 0xffffffff) 549125739cbSJeremy Kerr return -EINVAL; 550125739cbSJeremy Kerr 551125739cbSJeremy Kerr for (total_len = 0; total_len < count; total_len += read_len) { 552125739cbSJeremy Kerr read_len = min_t(size_t, count, 4); 553125739cbSJeremy Kerr read_len -= off & 0x3; 554125739cbSJeremy Kerr 555125739cbSJeremy Kerr rc = fsi_slave_read(slave, off, buf + total_len, read_len); 556125739cbSJeremy Kerr if (rc) 557125739cbSJeremy Kerr return rc; 558125739cbSJeremy Kerr 559125739cbSJeremy Kerr off += read_len; 560125739cbSJeremy Kerr } 561125739cbSJeremy Kerr 562125739cbSJeremy Kerr return count; 563125739cbSJeremy Kerr } 564125739cbSJeremy Kerr 565125739cbSJeremy Kerr static ssize_t fsi_slave_sysfs_raw_write(struct file *file, 566125739cbSJeremy Kerr struct kobject *kobj, struct bin_attribute *attr, 567125739cbSJeremy Kerr char *buf, loff_t off, size_t count) 568125739cbSJeremy Kerr { 569125739cbSJeremy Kerr struct fsi_slave *slave = to_fsi_slave(kobj_to_dev(kobj)); 570125739cbSJeremy Kerr size_t total_len, write_len; 571125739cbSJeremy Kerr int rc; 572125739cbSJeremy Kerr 573125739cbSJeremy Kerr if (off < 0) 574125739cbSJeremy Kerr return -EINVAL; 575125739cbSJeremy Kerr 576125739cbSJeremy Kerr if (off > 0xffffffff || count > 0xffffffff || off + count > 0xffffffff) 577125739cbSJeremy Kerr return -EINVAL; 578125739cbSJeremy Kerr 579125739cbSJeremy Kerr for (total_len = 0; total_len < count; total_len += write_len) { 580125739cbSJeremy Kerr write_len = min_t(size_t, count, 4); 581125739cbSJeremy Kerr write_len -= off & 0x3; 582125739cbSJeremy Kerr 583125739cbSJeremy Kerr rc = fsi_slave_write(slave, off, buf + total_len, write_len); 584125739cbSJeremy Kerr if (rc) 585125739cbSJeremy Kerr return rc; 586125739cbSJeremy Kerr 587125739cbSJeremy Kerr off += write_len; 588125739cbSJeremy Kerr } 589125739cbSJeremy Kerr 590125739cbSJeremy Kerr return count; 591125739cbSJeremy Kerr } 592125739cbSJeremy Kerr 593061c0958SBhumika Goyal static const struct bin_attribute fsi_slave_raw_attr = { 594125739cbSJeremy Kerr .attr = { 595125739cbSJeremy Kerr .name = "raw", 596125739cbSJeremy Kerr .mode = 0600, 597125739cbSJeremy Kerr }, 598125739cbSJeremy Kerr .size = 0, 599125739cbSJeremy Kerr .read = fsi_slave_sysfs_raw_read, 600125739cbSJeremy Kerr .write = fsi_slave_sysfs_raw_write, 601125739cbSJeremy Kerr }; 602125739cbSJeremy Kerr 603125739cbSJeremy Kerr static ssize_t fsi_slave_sysfs_term_write(struct file *file, 604125739cbSJeremy Kerr struct kobject *kobj, struct bin_attribute *attr, 605125739cbSJeremy Kerr char *buf, loff_t off, size_t count) 606125739cbSJeremy Kerr { 607125739cbSJeremy Kerr struct fsi_slave *slave = to_fsi_slave(kobj_to_dev(kobj)); 608125739cbSJeremy Kerr struct fsi_master *master = slave->master; 609125739cbSJeremy Kerr 610125739cbSJeremy Kerr if (!master->term) 611125739cbSJeremy Kerr return -ENODEV; 612125739cbSJeremy Kerr 613125739cbSJeremy Kerr master->term(master, slave->link, slave->id); 614125739cbSJeremy Kerr return count; 615125739cbSJeremy Kerr } 616125739cbSJeremy Kerr 617061c0958SBhumika Goyal static const struct bin_attribute fsi_slave_term_attr = { 618125739cbSJeremy Kerr .attr = { 619125739cbSJeremy Kerr .name = "term", 620125739cbSJeremy Kerr .mode = 0200, 621125739cbSJeremy Kerr }, 622125739cbSJeremy Kerr .size = 0, 623125739cbSJeremy Kerr .write = fsi_slave_sysfs_term_write, 624125739cbSJeremy Kerr }; 625125739cbSJeremy Kerr 6262b545cd8SJeremy Kerr static void fsi_slave_release(struct device *dev) 6272b545cd8SJeremy Kerr { 6282b545cd8SJeremy Kerr struct fsi_slave *slave = to_fsi_slave(dev); 6292b545cd8SJeremy Kerr 630f6a2f8ebSJeremy Kerr of_node_put(dev->of_node); 6312b545cd8SJeremy Kerr kfree(slave); 6322b545cd8SJeremy Kerr } 6332b545cd8SJeremy Kerr 634f6a2f8ebSJeremy Kerr static bool fsi_slave_node_matches(struct device_node *np, 635f6a2f8ebSJeremy Kerr int link, uint8_t id) 636f6a2f8ebSJeremy Kerr { 637f6a2f8ebSJeremy Kerr unsigned int len, na, ns; 638f6a2f8ebSJeremy Kerr const __be32 *prop; 639f6a2f8ebSJeremy Kerr 640f6a2f8ebSJeremy Kerr na = of_n_addr_cells(np); 641f6a2f8ebSJeremy Kerr ns = of_n_size_cells(np); 642f6a2f8ebSJeremy Kerr 643f6a2f8ebSJeremy Kerr /* Ensure we have the correct format for addresses and sizes in 644f6a2f8ebSJeremy Kerr * reg properties 645f6a2f8ebSJeremy Kerr */ 646f6a2f8ebSJeremy Kerr if (na != 2 || ns != 0) 647f6a2f8ebSJeremy Kerr return false; 648f6a2f8ebSJeremy Kerr 649f6a2f8ebSJeremy Kerr prop = of_get_property(np, "reg", &len); 650f6a2f8ebSJeremy Kerr if (!prop || len != 8) 651f6a2f8ebSJeremy Kerr return false; 652f6a2f8ebSJeremy Kerr 653f6a2f8ebSJeremy Kerr return (of_read_number(prop, 1) == link) && 654f6a2f8ebSJeremy Kerr (of_read_number(prop + 1, 1) == id); 655f6a2f8ebSJeremy Kerr } 656f6a2f8ebSJeremy Kerr 657f6a2f8ebSJeremy Kerr /* Find a matching node for the slave at (link, id). Returns NULL if none 658f6a2f8ebSJeremy Kerr * found, or a matching node with refcount already incremented. 659f6a2f8ebSJeremy Kerr */ 660f6a2f8ebSJeremy Kerr static struct device_node *fsi_slave_find_of_node(struct fsi_master *master, 661f6a2f8ebSJeremy Kerr int link, uint8_t id) 662f6a2f8ebSJeremy Kerr { 663f6a2f8ebSJeremy Kerr struct device_node *parent, *np; 664f6a2f8ebSJeremy Kerr 665f6a2f8ebSJeremy Kerr parent = dev_of_node(&master->dev); 666f6a2f8ebSJeremy Kerr if (!parent) 667f6a2f8ebSJeremy Kerr return NULL; 668f6a2f8ebSJeremy Kerr 669f6a2f8ebSJeremy Kerr for_each_child_of_node(parent, np) { 670f6a2f8ebSJeremy Kerr if (fsi_slave_node_matches(np, link, id)) 671f6a2f8ebSJeremy Kerr return np; 672f6a2f8ebSJeremy Kerr } 673f6a2f8ebSJeremy Kerr 674f6a2f8ebSJeremy Kerr return NULL; 675f6a2f8ebSJeremy Kerr } 676f6a2f8ebSJeremy Kerr 677a2e7da86SBenjamin Herrenschmidt static ssize_t slave_send_echo_show(struct device *dev, 678a2e7da86SBenjamin Herrenschmidt struct device_attribute *attr, 679a2e7da86SBenjamin Herrenschmidt char *buf) 680a2e7da86SBenjamin Herrenschmidt { 681a2e7da86SBenjamin Herrenschmidt struct fsi_slave *slave = to_fsi_slave(dev); 682a2e7da86SBenjamin Herrenschmidt 683a2e7da86SBenjamin Herrenschmidt return sprintf(buf, "%u\n", slave->t_send_delay); 684a2e7da86SBenjamin Herrenschmidt } 685a2e7da86SBenjamin Herrenschmidt 686a2e7da86SBenjamin Herrenschmidt static ssize_t slave_send_echo_store(struct device *dev, 687a2e7da86SBenjamin Herrenschmidt struct device_attribute *attr, const char *buf, size_t count) 688a2e7da86SBenjamin Herrenschmidt { 689a2e7da86SBenjamin Herrenschmidt struct fsi_slave *slave = to_fsi_slave(dev); 690a2e7da86SBenjamin Herrenschmidt struct fsi_master *master = slave->master; 691a2e7da86SBenjamin Herrenschmidt unsigned long val; 692a2e7da86SBenjamin Herrenschmidt int rc; 693a2e7da86SBenjamin Herrenschmidt 694a2e7da86SBenjamin Herrenschmidt if (kstrtoul(buf, 0, &val) < 0) 695a2e7da86SBenjamin Herrenschmidt return -EINVAL; 696a2e7da86SBenjamin Herrenschmidt 697a2e7da86SBenjamin Herrenschmidt if (val < 1 || val > 16) 698a2e7da86SBenjamin Herrenschmidt return -EINVAL; 699a2e7da86SBenjamin Herrenschmidt 700a2e7da86SBenjamin Herrenschmidt if (!master->link_config) 701a2e7da86SBenjamin Herrenschmidt return -ENXIO; 702a2e7da86SBenjamin Herrenschmidt 703a2e7da86SBenjamin Herrenschmidt /* Current HW mandates that send and echo delay are identical */ 704a2e7da86SBenjamin Herrenschmidt slave->t_send_delay = val; 705a2e7da86SBenjamin Herrenschmidt slave->t_echo_delay = val; 706a2e7da86SBenjamin Herrenschmidt 707a2e7da86SBenjamin Herrenschmidt rc = fsi_slave_set_smode(slave); 708a2e7da86SBenjamin Herrenschmidt if (rc < 0) 709a2e7da86SBenjamin Herrenschmidt return rc; 710a2e7da86SBenjamin Herrenschmidt if (master->link_config) 711a2e7da86SBenjamin Herrenschmidt master->link_config(master, slave->link, 712a2e7da86SBenjamin Herrenschmidt slave->t_send_delay, 713a2e7da86SBenjamin Herrenschmidt slave->t_echo_delay); 714a2e7da86SBenjamin Herrenschmidt 715a2e7da86SBenjamin Herrenschmidt return count; 716a2e7da86SBenjamin Herrenschmidt } 717a2e7da86SBenjamin Herrenschmidt 718a2e7da86SBenjamin Herrenschmidt static DEVICE_ATTR(send_echo_delays, 0600, 719a2e7da86SBenjamin Herrenschmidt slave_send_echo_show, slave_send_echo_store); 720a2e7da86SBenjamin Herrenschmidt 7210a213777SBenjamin Herrenschmidt static ssize_t chip_id_show(struct device *dev, 7220a213777SBenjamin Herrenschmidt struct device_attribute *attr, 7230a213777SBenjamin Herrenschmidt char *buf) 7240a213777SBenjamin Herrenschmidt { 7250a213777SBenjamin Herrenschmidt struct fsi_slave *slave = to_fsi_slave(dev); 7260a213777SBenjamin Herrenschmidt 7270a213777SBenjamin Herrenschmidt return sprintf(buf, "%d\n", slave->chip_id); 7280a213777SBenjamin Herrenschmidt } 7290a213777SBenjamin Herrenschmidt 7300a213777SBenjamin Herrenschmidt static DEVICE_ATTR_RO(chip_id); 7310a213777SBenjamin Herrenschmidt 732414c1026SJeremy Kerr static int fsi_slave_init(struct fsi_master *master, int link, uint8_t id) 733414c1026SJeremy Kerr { 73411454d6dSJoel Stanley uint32_t chip_id; 7352b545cd8SJeremy Kerr struct fsi_slave *slave; 7362b545cd8SJeremy Kerr uint8_t crc; 73711454d6dSJoel Stanley __be32 data, llmode; 7382b545cd8SJeremy Kerr int rc; 739414c1026SJeremy Kerr 7402b545cd8SJeremy Kerr /* Currently, we only support single slaves on a link, and use the 7412b545cd8SJeremy Kerr * full 23-bit address range 7422b545cd8SJeremy Kerr */ 7432b545cd8SJeremy Kerr if (id != 0) 7442b545cd8SJeremy Kerr return -EINVAL; 7452b545cd8SJeremy Kerr 74611454d6dSJoel Stanley rc = fsi_master_read(master, link, id, 0, &data, sizeof(data)); 7472b545cd8SJeremy Kerr if (rc) { 7482b545cd8SJeremy Kerr dev_dbg(&master->dev, "can't read slave %02x:%02x %d\n", 7492b545cd8SJeremy Kerr link, id, rc); 750414c1026SJeremy Kerr return -ENODEV; 751414c1026SJeremy Kerr } 75211454d6dSJoel Stanley chip_id = be32_to_cpu(data); 7532b545cd8SJeremy Kerr 7542b545cd8SJeremy Kerr crc = crc4(0, chip_id, 32); 7552b545cd8SJeremy Kerr if (crc) { 7562b545cd8SJeremy Kerr dev_warn(&master->dev, "slave %02x:%02x invalid chip id CRC!\n", 7572b545cd8SJeremy Kerr link, id); 7582b545cd8SJeremy Kerr return -EIO; 7592b545cd8SJeremy Kerr } 7602b545cd8SJeremy Kerr 761638bd9acSChristopher Bostic dev_dbg(&master->dev, "fsi: found chip %08x at %02x:%02x:%02x\n", 7622b545cd8SJeremy Kerr chip_id, master->idx, link, id); 7632b545cd8SJeremy Kerr 7644af889b0SJeremy Kerr /* If we're behind a master that doesn't provide a self-running bus 7654af889b0SJeremy Kerr * clock, put the slave into async mode 7664af889b0SJeremy Kerr */ 7674af889b0SJeremy Kerr if (master->flags & FSI_MASTER_FLAG_SWCLOCK) { 7684af889b0SJeremy Kerr llmode = cpu_to_be32(FSI_LLMODE_ASYNC); 7694af889b0SJeremy Kerr rc = fsi_master_write(master, link, id, 7704af889b0SJeremy Kerr FSI_SLAVE_BASE + FSI_LLMODE, 7714af889b0SJeremy Kerr &llmode, sizeof(llmode)); 7724af889b0SJeremy Kerr if (rc) 7734af889b0SJeremy Kerr dev_warn(&master->dev, 7744af889b0SJeremy Kerr "can't set llmode on slave:%02x:%02x %d\n", 7754af889b0SJeremy Kerr link, id, rc); 7764af889b0SJeremy Kerr } 7774af889b0SJeremy Kerr 7782b545cd8SJeremy Kerr /* We can communicate with a slave; create the slave device and 7792b545cd8SJeremy Kerr * register. 7802b545cd8SJeremy Kerr */ 7812b545cd8SJeremy Kerr slave = kzalloc(sizeof(*slave), GFP_KERNEL); 7822b545cd8SJeremy Kerr if (!slave) 7832b545cd8SJeremy Kerr return -ENOMEM; 7842b545cd8SJeremy Kerr 7852b545cd8SJeremy Kerr slave->master = master; 7862b545cd8SJeremy Kerr slave->dev.parent = &master->dev; 787f6a2f8ebSJeremy Kerr slave->dev.of_node = fsi_slave_find_of_node(master, link, id); 7882b545cd8SJeremy Kerr slave->dev.release = fsi_slave_release; 7892b545cd8SJeremy Kerr slave->link = link; 7902b545cd8SJeremy Kerr slave->id = id; 7912b545cd8SJeremy Kerr slave->size = FSI_SLAVE_SIZE_23b; 792a2e7da86SBenjamin Herrenschmidt slave->t_send_delay = 16; 793a2e7da86SBenjamin Herrenschmidt slave->t_echo_delay = 16; 794a2e7da86SBenjamin Herrenschmidt 7950a213777SBenjamin Herrenschmidt /* Get chip ID if any */ 7960a213777SBenjamin Herrenschmidt slave->chip_id = -1; 7970a213777SBenjamin Herrenschmidt if (slave->dev.of_node) { 7980a213777SBenjamin Herrenschmidt uint32_t prop; 7990a213777SBenjamin Herrenschmidt if (!of_property_read_u32(slave->dev.of_node, "chip-id", &prop)) 8000a213777SBenjamin Herrenschmidt slave->chip_id = prop; 8010a213777SBenjamin Herrenschmidt 8020a213777SBenjamin Herrenschmidt } 803a2e7da86SBenjamin Herrenschmidt rc = fsi_slave_set_smode(slave); 804a2e7da86SBenjamin Herrenschmidt if (rc) { 805a2e7da86SBenjamin Herrenschmidt dev_warn(&master->dev, 806a2e7da86SBenjamin Herrenschmidt "can't set smode on slave:%02x:%02x %d\n", 807a2e7da86SBenjamin Herrenschmidt link, id, rc); 808a2e7da86SBenjamin Herrenschmidt kfree(slave); 809a2e7da86SBenjamin Herrenschmidt return -ENODEV; 810a2e7da86SBenjamin Herrenschmidt } 811a2e7da86SBenjamin Herrenschmidt if (master->link_config) 812a2e7da86SBenjamin Herrenschmidt master->link_config(master, link, 813a2e7da86SBenjamin Herrenschmidt slave->t_send_delay, 814a2e7da86SBenjamin Herrenschmidt slave->t_echo_delay); 8152b545cd8SJeremy Kerr 8162b545cd8SJeremy Kerr dev_set_name(&slave->dev, "slave@%02x:%02x", link, id); 8172b545cd8SJeremy Kerr rc = device_register(&slave->dev); 8182b545cd8SJeremy Kerr if (rc < 0) { 8192b545cd8SJeremy Kerr dev_warn(&master->dev, "failed to create slave device: %d\n", 8202b545cd8SJeremy Kerr rc); 8212b545cd8SJeremy Kerr put_device(&slave->dev); 8222b545cd8SJeremy Kerr return rc; 8232b545cd8SJeremy Kerr } 8242b545cd8SJeremy Kerr 825125739cbSJeremy Kerr rc = device_create_bin_file(&slave->dev, &fsi_slave_raw_attr); 826125739cbSJeremy Kerr if (rc) 827125739cbSJeremy Kerr dev_warn(&slave->dev, "failed to create raw attr: %d\n", rc); 828125739cbSJeremy Kerr 829125739cbSJeremy Kerr rc = device_create_bin_file(&slave->dev, &fsi_slave_term_attr); 830125739cbSJeremy Kerr if (rc) 831125739cbSJeremy Kerr dev_warn(&slave->dev, "failed to create term attr: %d\n", rc); 832125739cbSJeremy Kerr 833a2e7da86SBenjamin Herrenschmidt rc = device_create_file(&slave->dev, &dev_attr_send_echo_delays); 834a2e7da86SBenjamin Herrenschmidt if (rc) 835a2e7da86SBenjamin Herrenschmidt dev_warn(&slave->dev, "failed to create delay attr: %d\n", rc); 836a2e7da86SBenjamin Herrenschmidt 8370a213777SBenjamin Herrenschmidt rc = device_create_file(&slave->dev, &dev_attr_chip_id); 8380a213777SBenjamin Herrenschmidt if (rc) 8390a213777SBenjamin Herrenschmidt dev_warn(&slave->dev, "failed to create chip id: %d\n", rc); 8400a213777SBenjamin Herrenschmidt 841f7ade2a6SJeremy Kerr rc = fsi_slave_scan(slave); 842f7ade2a6SJeremy Kerr if (rc) 843f7ade2a6SJeremy Kerr dev_dbg(&master->dev, "failed during slave scan with: %d\n", 844f7ade2a6SJeremy Kerr rc); 8452b545cd8SJeremy Kerr 8462b545cd8SJeremy Kerr return rc; 8472b545cd8SJeremy Kerr } 848414c1026SJeremy Kerr 84909aecfabSJeremy Kerr /* FSI master support */ 850014c2abcSJeremy Kerr static int fsi_check_access(uint32_t addr, size_t size) 851014c2abcSJeremy Kerr { 85299f039e9SEddie James if (size == 4) { 85399f039e9SEddie James if (addr & 0x3) 854014c2abcSJeremy Kerr return -EINVAL; 85599f039e9SEddie James } else if (size == 2) { 85699f039e9SEddie James if (addr & 0x1) 85799f039e9SEddie James return -EINVAL; 85899f039e9SEddie James } else if (size != 1) 859014c2abcSJeremy Kerr return -EINVAL; 860014c2abcSJeremy Kerr 861014c2abcSJeremy Kerr return 0; 862014c2abcSJeremy Kerr } 863014c2abcSJeremy Kerr 864014c2abcSJeremy Kerr static int fsi_master_read(struct fsi_master *master, int link, 865014c2abcSJeremy Kerr uint8_t slave_id, uint32_t addr, void *val, size_t size) 866014c2abcSJeremy Kerr { 867014c2abcSJeremy Kerr int rc; 868014c2abcSJeremy Kerr 86966433b05SJeremy Kerr trace_fsi_master_read(master, link, slave_id, addr, size); 870014c2abcSJeremy Kerr 87166433b05SJeremy Kerr rc = fsi_check_access(addr, size); 87266433b05SJeremy Kerr if (!rc) 87366433b05SJeremy Kerr rc = master->read(master, link, slave_id, addr, val, size); 87466433b05SJeremy Kerr 87566433b05SJeremy Kerr trace_fsi_master_rw_result(master, link, slave_id, addr, size, 87666433b05SJeremy Kerr false, val, rc); 87766433b05SJeremy Kerr 87866433b05SJeremy Kerr return rc; 879014c2abcSJeremy Kerr } 880014c2abcSJeremy Kerr 881014c2abcSJeremy Kerr static int fsi_master_write(struct fsi_master *master, int link, 882014c2abcSJeremy Kerr uint8_t slave_id, uint32_t addr, const void *val, size_t size) 883014c2abcSJeremy Kerr { 884014c2abcSJeremy Kerr int rc; 885014c2abcSJeremy Kerr 88666433b05SJeremy Kerr trace_fsi_master_write(master, link, slave_id, addr, size, val); 887014c2abcSJeremy Kerr 88866433b05SJeremy Kerr rc = fsi_check_access(addr, size); 88966433b05SJeremy Kerr if (!rc) 89066433b05SJeremy Kerr rc = master->write(master, link, slave_id, addr, val, size); 89166433b05SJeremy Kerr 89266433b05SJeremy Kerr trace_fsi_master_rw_result(master, link, slave_id, addr, size, 89366433b05SJeremy Kerr true, val, rc); 89466433b05SJeremy Kerr 89566433b05SJeremy Kerr return rc; 896014c2abcSJeremy Kerr } 897014c2abcSJeremy Kerr 89826095282SChristopher Bostic static int fsi_master_link_enable(struct fsi_master *master, int link) 89926095282SChristopher Bostic { 90026095282SChristopher Bostic if (master->link_enable) 90126095282SChristopher Bostic return master->link_enable(master, link); 90226095282SChristopher Bostic 90326095282SChristopher Bostic return 0; 90426095282SChristopher Bostic } 90526095282SChristopher Bostic 90626095282SChristopher Bostic /* 90726095282SChristopher Bostic * Issue a break command on this link 90826095282SChristopher Bostic */ 90926095282SChristopher Bostic static int fsi_master_break(struct fsi_master *master, int link) 91026095282SChristopher Bostic { 911a2e7da86SBenjamin Herrenschmidt int rc = 0; 912a2e7da86SBenjamin Herrenschmidt 91366433b05SJeremy Kerr trace_fsi_master_break(master, link); 91466433b05SJeremy Kerr 91526095282SChristopher Bostic if (master->send_break) 916a2e7da86SBenjamin Herrenschmidt rc = master->send_break(master, link); 917a2e7da86SBenjamin Herrenschmidt if (master->link_config) 918a2e7da86SBenjamin Herrenschmidt master->link_config(master, link, 16, 16); 91926095282SChristopher Bostic 920a2e7da86SBenjamin Herrenschmidt return rc; 92126095282SChristopher Bostic } 92226095282SChristopher Bostic 923414c1026SJeremy Kerr static int fsi_master_scan(struct fsi_master *master) 924414c1026SJeremy Kerr { 92526095282SChristopher Bostic int link, rc; 926414c1026SJeremy Kerr 92726095282SChristopher Bostic for (link = 0; link < master->n_links; link++) { 92826095282SChristopher Bostic rc = fsi_master_link_enable(master, link); 92926095282SChristopher Bostic if (rc) { 93026095282SChristopher Bostic dev_dbg(&master->dev, 93126095282SChristopher Bostic "enable link %d failed: %d\n", link, rc); 93226095282SChristopher Bostic continue; 93326095282SChristopher Bostic } 93426095282SChristopher Bostic rc = fsi_master_break(master, link); 93526095282SChristopher Bostic if (rc) { 93626095282SChristopher Bostic dev_dbg(&master->dev, 93726095282SChristopher Bostic "break to link %d failed: %d\n", link, rc); 93826095282SChristopher Bostic continue; 93926095282SChristopher Bostic } 94026095282SChristopher Bostic 941414c1026SJeremy Kerr fsi_slave_init(master, link, 0); 94226095282SChristopher Bostic } 943414c1026SJeremy Kerr 944414c1026SJeremy Kerr return 0; 945414c1026SJeremy Kerr } 946414c1026SJeremy Kerr 947cd0fdb5cSChristopher Bostic static int fsi_slave_remove_device(struct device *dev, void *arg) 948cd0fdb5cSChristopher Bostic { 949cd0fdb5cSChristopher Bostic device_unregister(dev); 950cd0fdb5cSChristopher Bostic return 0; 951cd0fdb5cSChristopher Bostic } 952cd0fdb5cSChristopher Bostic 953cd0fdb5cSChristopher Bostic static int fsi_master_remove_slave(struct device *dev, void *arg) 954cd0fdb5cSChristopher Bostic { 955cd0fdb5cSChristopher Bostic device_for_each_child(dev, NULL, fsi_slave_remove_device); 956cd0fdb5cSChristopher Bostic device_unregister(dev); 957cd0fdb5cSChristopher Bostic return 0; 958cd0fdb5cSChristopher Bostic } 959cd0fdb5cSChristopher Bostic 960cd0fdb5cSChristopher Bostic static void fsi_master_unscan(struct fsi_master *master) 961cd0fdb5cSChristopher Bostic { 962cd0fdb5cSChristopher Bostic device_for_each_child(&master->dev, NULL, fsi_master_remove_slave); 963cd0fdb5cSChristopher Bostic } 964cd0fdb5cSChristopher Bostic 96515362d69SJeremy Kerr int fsi_master_rescan(struct fsi_master *master) 96615362d69SJeremy Kerr { 96715362d69SJeremy Kerr fsi_master_unscan(master); 96815362d69SJeremy Kerr return fsi_master_scan(master); 96915362d69SJeremy Kerr } 97015362d69SJeremy Kerr EXPORT_SYMBOL_GPL(fsi_master_rescan); 97115362d69SJeremy Kerr 972cd0fdb5cSChristopher Bostic static ssize_t master_rescan_store(struct device *dev, 973cd0fdb5cSChristopher Bostic struct device_attribute *attr, const char *buf, size_t count) 974cd0fdb5cSChristopher Bostic { 975cd0fdb5cSChristopher Bostic struct fsi_master *master = to_fsi_master(dev); 976cd0fdb5cSChristopher Bostic int rc; 977cd0fdb5cSChristopher Bostic 97815362d69SJeremy Kerr rc = fsi_master_rescan(master); 979cd0fdb5cSChristopher Bostic if (rc < 0) 980cd0fdb5cSChristopher Bostic return rc; 981cd0fdb5cSChristopher Bostic 982cd0fdb5cSChristopher Bostic return count; 983cd0fdb5cSChristopher Bostic } 984cd0fdb5cSChristopher Bostic 985cd0fdb5cSChristopher Bostic static DEVICE_ATTR(rescan, 0200, NULL, master_rescan_store); 986cd0fdb5cSChristopher Bostic 987125739cbSJeremy Kerr static ssize_t master_break_store(struct device *dev, 988125739cbSJeremy Kerr struct device_attribute *attr, const char *buf, size_t count) 989125739cbSJeremy Kerr { 990125739cbSJeremy Kerr struct fsi_master *master = to_fsi_master(dev); 991125739cbSJeremy Kerr 992125739cbSJeremy Kerr fsi_master_break(master, 0); 993125739cbSJeremy Kerr 994125739cbSJeremy Kerr return count; 995125739cbSJeremy Kerr } 996125739cbSJeremy Kerr 997125739cbSJeremy Kerr static DEVICE_ATTR(break, 0200, NULL, master_break_store); 998125739cbSJeremy Kerr 99909aecfabSJeremy Kerr int fsi_master_register(struct fsi_master *master) 100009aecfabSJeremy Kerr { 100109aecfabSJeremy Kerr int rc; 1002f3aa2c6fSChristopher Bostic struct device_node *np; 100309aecfabSJeremy Kerr 100409aecfabSJeremy Kerr master->idx = ida_simple_get(&master_ida, 0, INT_MAX, GFP_KERNEL); 100509aecfabSJeremy Kerr dev_set_name(&master->dev, "fsi%d", master->idx); 100609aecfabSJeremy Kerr 100709aecfabSJeremy Kerr rc = device_register(&master->dev); 1008414c1026SJeremy Kerr if (rc) { 100909aecfabSJeremy Kerr ida_simple_remove(&master_ida, master->idx); 101009aecfabSJeremy Kerr return rc; 101109aecfabSJeremy Kerr } 1012414c1026SJeremy Kerr 1013cd0fdb5cSChristopher Bostic rc = device_create_file(&master->dev, &dev_attr_rescan); 1014cd0fdb5cSChristopher Bostic if (rc) { 1015265aac26SBenjamin Herrenschmidt device_del(&master->dev); 1016cd0fdb5cSChristopher Bostic ida_simple_remove(&master_ida, master->idx); 1017cd0fdb5cSChristopher Bostic return rc; 1018cd0fdb5cSChristopher Bostic } 1019cd0fdb5cSChristopher Bostic 1020125739cbSJeremy Kerr rc = device_create_file(&master->dev, &dev_attr_break); 1021125739cbSJeremy Kerr if (rc) { 1022265aac26SBenjamin Herrenschmidt device_del(&master->dev); 1023125739cbSJeremy Kerr ida_simple_remove(&master_ida, master->idx); 1024125739cbSJeremy Kerr return rc; 1025125739cbSJeremy Kerr } 1026125739cbSJeremy Kerr 1027f3aa2c6fSChristopher Bostic np = dev_of_node(&master->dev); 1028f3aa2c6fSChristopher Bostic if (!of_property_read_bool(np, "no-scan-on-init")) 1029414c1026SJeremy Kerr fsi_master_scan(master); 1030cd0fdb5cSChristopher Bostic 1031414c1026SJeremy Kerr return 0; 1032414c1026SJeremy Kerr } 103309aecfabSJeremy Kerr EXPORT_SYMBOL_GPL(fsi_master_register); 103409aecfabSJeremy Kerr 103509aecfabSJeremy Kerr void fsi_master_unregister(struct fsi_master *master) 103609aecfabSJeremy Kerr { 103709aecfabSJeremy Kerr if (master->idx >= 0) { 103809aecfabSJeremy Kerr ida_simple_remove(&master_ida, master->idx); 103909aecfabSJeremy Kerr master->idx = -1; 104009aecfabSJeremy Kerr } 104109aecfabSJeremy Kerr 1042cd0fdb5cSChristopher Bostic fsi_master_unscan(master); 104309aecfabSJeremy Kerr device_unregister(&master->dev); 104409aecfabSJeremy Kerr } 104509aecfabSJeremy Kerr EXPORT_SYMBOL_GPL(fsi_master_unregister); 104609aecfabSJeremy Kerr 10470508ad1fSJeremy Kerr /* FSI core & Linux bus type definitions */ 10480508ad1fSJeremy Kerr 1049dd37eed7SJeremy Kerr static int fsi_bus_match(struct device *dev, struct device_driver *drv) 1050dd37eed7SJeremy Kerr { 1051dd37eed7SJeremy Kerr struct fsi_device *fsi_dev = to_fsi_dev(dev); 1052dd37eed7SJeremy Kerr struct fsi_driver *fsi_drv = to_fsi_drv(drv); 1053dd37eed7SJeremy Kerr const struct fsi_device_id *id; 1054dd37eed7SJeremy Kerr 1055dd37eed7SJeremy Kerr if (!fsi_drv->id_table) 1056dd37eed7SJeremy Kerr return 0; 1057dd37eed7SJeremy Kerr 1058dd37eed7SJeremy Kerr for (id = fsi_drv->id_table; id->engine_type; id++) { 1059dd37eed7SJeremy Kerr if (id->engine_type != fsi_dev->engine_type) 1060dd37eed7SJeremy Kerr continue; 1061dd37eed7SJeremy Kerr if (id->version == FSI_VERSION_ANY || 1062dd37eed7SJeremy Kerr id->version == fsi_dev->version) 1063dd37eed7SJeremy Kerr return 1; 1064dd37eed7SJeremy Kerr } 1065dd37eed7SJeremy Kerr 1066dd37eed7SJeremy Kerr return 0; 1067dd37eed7SJeremy Kerr } 1068dd37eed7SJeremy Kerr 1069356d8009SChristopher Bostic int fsi_driver_register(struct fsi_driver *fsi_drv) 1070356d8009SChristopher Bostic { 1071356d8009SChristopher Bostic if (!fsi_drv) 1072356d8009SChristopher Bostic return -EINVAL; 1073356d8009SChristopher Bostic if (!fsi_drv->id_table) 1074356d8009SChristopher Bostic return -EINVAL; 1075356d8009SChristopher Bostic 1076356d8009SChristopher Bostic return driver_register(&fsi_drv->drv); 1077356d8009SChristopher Bostic } 1078356d8009SChristopher Bostic EXPORT_SYMBOL_GPL(fsi_driver_register); 1079356d8009SChristopher Bostic 1080356d8009SChristopher Bostic void fsi_driver_unregister(struct fsi_driver *fsi_drv) 1081356d8009SChristopher Bostic { 1082356d8009SChristopher Bostic driver_unregister(&fsi_drv->drv); 1083356d8009SChristopher Bostic } 1084356d8009SChristopher Bostic EXPORT_SYMBOL_GPL(fsi_driver_unregister); 1085356d8009SChristopher Bostic 10860508ad1fSJeremy Kerr struct bus_type fsi_bus_type = { 10870508ad1fSJeremy Kerr .name = "fsi", 1088dd37eed7SJeremy Kerr .match = fsi_bus_match, 10890508ad1fSJeremy Kerr }; 10900508ad1fSJeremy Kerr EXPORT_SYMBOL_GPL(fsi_bus_type); 10910508ad1fSJeremy Kerr 1092496f8931SJoel Stanley static int __init fsi_init(void) 10930508ad1fSJeremy Kerr { 10940508ad1fSJeremy Kerr return bus_register(&fsi_bus_type); 10950508ad1fSJeremy Kerr } 1096496f8931SJoel Stanley postcore_initcall(fsi_init); 10970508ad1fSJeremy Kerr 10980508ad1fSJeremy Kerr static void fsi_exit(void) 10990508ad1fSJeremy Kerr { 11000508ad1fSJeremy Kerr bus_unregister(&fsi_bus_type); 11010508ad1fSJeremy Kerr } 11020508ad1fSJeremy Kerr module_exit(fsi_exit); 11031fa847d7SJeremy Kerr module_param(discard_errors, int, 0664); 1104acb7e8f7SChristopher Bostic MODULE_LICENSE("GPL"); 11051fa847d7SJeremy Kerr MODULE_PARM_DESC(discard_errors, "Don't invoke error handling on bus accesses"); 1106