109c434b8SThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only 2ac0385d9SChristopher Bostic /* 3ac0385d9SChristopher Bostic * A FSI master controller, using a simple GPIO bit-banging interface 4ac0385d9SChristopher Bostic */ 5ac0385d9SChristopher Bostic 6ac0385d9SChristopher Bostic #include <linux/crc4.h> 7ac0385d9SChristopher Bostic #include <linux/delay.h> 8ac0385d9SChristopher Bostic #include <linux/device.h> 9ac0385d9SChristopher Bostic #include <linux/fsi.h> 10ac0385d9SChristopher Bostic #include <linux/gpio/consumer.h> 11ac0385d9SChristopher Bostic #include <linux/io.h> 1226d79b27SJeremy Kerr #include <linux/irqflags.h> 13ac0385d9SChristopher Bostic #include <linux/module.h> 14f6a2f8ebSJeremy Kerr #include <linux/of.h> 15ac0385d9SChristopher Bostic #include <linux/platform_device.h> 16ac0385d9SChristopher Bostic #include <linux/slab.h> 17ac0385d9SChristopher Bostic 18ac0385d9SChristopher Bostic #include "fsi-master.h" 19ac0385d9SChristopher Bostic 20ac0385d9SChristopher Bostic #define FSI_GPIO_STD_DLY 1 /* Standard pin delay in nS */ 210e82e5c1SJeremy Kerr #define LAST_ADDR_INVALID 0x1 220e82e5c1SJeremy Kerr 23ac0385d9SChristopher Bostic struct fsi_master_gpio { 24ac0385d9SChristopher Bostic struct fsi_master master; 25ac0385d9SChristopher Bostic struct device *dev; 26e5538139SJeremy Kerr struct mutex cmd_lock; /* mutex for command ordering */ 27ac0385d9SChristopher Bostic struct gpio_desc *gpio_clk; 28ac0385d9SChristopher Bostic struct gpio_desc *gpio_data; 29ac0385d9SChristopher Bostic struct gpio_desc *gpio_trans; /* Voltage translator */ 30ac0385d9SChristopher Bostic struct gpio_desc *gpio_enable; /* FSI enable */ 31ac0385d9SChristopher Bostic struct gpio_desc *gpio_mux; /* Mux control */ 32b8bd146dSJeremy Kerr bool external_mode; 33bc1099d2SBenjamin Herrenschmidt bool no_delays; 340e82e5c1SJeremy Kerr uint32_t last_addr; 3575854c14SBenjamin Herrenschmidt uint8_t t_send_delay; 3675854c14SBenjamin Herrenschmidt uint8_t t_echo_delay; 37ac0385d9SChristopher Bostic }; 38ac0385d9SChristopher Bostic 391247cf7aSJeremy Kerr #define CREATE_TRACE_POINTS 401247cf7aSJeremy Kerr #include <trace/events/fsi_master_gpio.h> 411247cf7aSJeremy Kerr 42ac0385d9SChristopher Bostic #define to_fsi_master_gpio(m) container_of(m, struct fsi_master_gpio, master) 43ac0385d9SChristopher Bostic 44ac0385d9SChristopher Bostic struct fsi_gpio_msg { 45ac0385d9SChristopher Bostic uint64_t msg; 46ac0385d9SChristopher Bostic uint8_t bits; 47ac0385d9SChristopher Bostic }; 48ac0385d9SChristopher Bostic 49ac0385d9SChristopher Bostic static void clock_toggle(struct fsi_master_gpio *master, int count) 50ac0385d9SChristopher Bostic { 51ac0385d9SChristopher Bostic int i; 52ac0385d9SChristopher Bostic 53ac0385d9SChristopher Bostic for (i = 0; i < count; i++) { 54bc1099d2SBenjamin Herrenschmidt if (!master->no_delays) 55ac0385d9SChristopher Bostic ndelay(FSI_GPIO_STD_DLY); 56ac0385d9SChristopher Bostic gpiod_set_value(master->gpio_clk, 0); 57bc1099d2SBenjamin Herrenschmidt if (!master->no_delays) 58ac0385d9SChristopher Bostic ndelay(FSI_GPIO_STD_DLY); 59ac0385d9SChristopher Bostic gpiod_set_value(master->gpio_clk, 1); 60ac0385d9SChristopher Bostic } 61ac0385d9SChristopher Bostic } 62ac0385d9SChristopher Bostic 635d0d16f1SBenjamin Herrenschmidt static int sda_clock_in(struct fsi_master_gpio *master) 64ac0385d9SChristopher Bostic { 65ac0385d9SChristopher Bostic int in; 66ac0385d9SChristopher Bostic 67bc1099d2SBenjamin Herrenschmidt if (!master->no_delays) 68ac0385d9SChristopher Bostic ndelay(FSI_GPIO_STD_DLY); 695d0d16f1SBenjamin Herrenschmidt gpiod_set_value(master->gpio_clk, 0); 70f3ca4834SBenjamin Herrenschmidt 71f3ca4834SBenjamin Herrenschmidt /* Dummy read to feed the synchronizers */ 72f3ca4834SBenjamin Herrenschmidt gpiod_get_value(master->gpio_data); 73f3ca4834SBenjamin Herrenschmidt 74f3ca4834SBenjamin Herrenschmidt /* Actual data read */ 75ac0385d9SChristopher Bostic in = gpiod_get_value(master->gpio_data); 76bc1099d2SBenjamin Herrenschmidt if (!master->no_delays) 775d0d16f1SBenjamin Herrenschmidt ndelay(FSI_GPIO_STD_DLY); 785d0d16f1SBenjamin Herrenschmidt gpiod_set_value(master->gpio_clk, 1); 79ac0385d9SChristopher Bostic return in ? 1 : 0; 80ac0385d9SChristopher Bostic } 81ac0385d9SChristopher Bostic 82ac0385d9SChristopher Bostic static void sda_out(struct fsi_master_gpio *master, int value) 83ac0385d9SChristopher Bostic { 84ac0385d9SChristopher Bostic gpiod_set_value(master->gpio_data, value); 85ac0385d9SChristopher Bostic } 86ac0385d9SChristopher Bostic 87ac0385d9SChristopher Bostic static void set_sda_input(struct fsi_master_gpio *master) 88ac0385d9SChristopher Bostic { 89ac0385d9SChristopher Bostic gpiod_direction_input(master->gpio_data); 90ac0385d9SChristopher Bostic gpiod_set_value(master->gpio_trans, 0); 91ac0385d9SChristopher Bostic } 92ac0385d9SChristopher Bostic 93ac0385d9SChristopher Bostic static void set_sda_output(struct fsi_master_gpio *master, int value) 94ac0385d9SChristopher Bostic { 95ac0385d9SChristopher Bostic gpiod_set_value(master->gpio_trans, 1); 96ac0385d9SChristopher Bostic gpiod_direction_output(master->gpio_data, value); 97ac0385d9SChristopher Bostic } 98ac0385d9SChristopher Bostic 99ac0385d9SChristopher Bostic static void clock_zeros(struct fsi_master_gpio *master, int count) 100ac0385d9SChristopher Bostic { 101777fd524SBenjamin Herrenschmidt trace_fsi_master_gpio_clock_zeros(master, count); 102ac0385d9SChristopher Bostic set_sda_output(master, 1); 103ac0385d9SChristopher Bostic clock_toggle(master, count); 104ac0385d9SChristopher Bostic } 105ac0385d9SChristopher Bostic 106777fd524SBenjamin Herrenschmidt static void echo_delay(struct fsi_master_gpio *master) 107777fd524SBenjamin Herrenschmidt { 108777fd524SBenjamin Herrenschmidt clock_zeros(master, master->t_echo_delay); 109777fd524SBenjamin Herrenschmidt } 110777fd524SBenjamin Herrenschmidt 111777fd524SBenjamin Herrenschmidt 112ac0385d9SChristopher Bostic static void serial_in(struct fsi_master_gpio *master, struct fsi_gpio_msg *msg, 113ac0385d9SChristopher Bostic uint8_t num_bits) 114ac0385d9SChristopher Bostic { 115ac0385d9SChristopher Bostic uint8_t bit, in_bit; 116ac0385d9SChristopher Bostic 117ac0385d9SChristopher Bostic set_sda_input(master); 118ac0385d9SChristopher Bostic 119ac0385d9SChristopher Bostic for (bit = 0; bit < num_bits; bit++) { 1205d0d16f1SBenjamin Herrenschmidt in_bit = sda_clock_in(master); 121ac0385d9SChristopher Bostic msg->msg <<= 1; 122ac0385d9SChristopher Bostic msg->msg |= ~in_bit & 0x1; /* Data is active low */ 123ac0385d9SChristopher Bostic } 124ac0385d9SChristopher Bostic msg->bits += num_bits; 1251247cf7aSJeremy Kerr 1261247cf7aSJeremy Kerr trace_fsi_master_gpio_in(master, num_bits, msg->msg); 127ac0385d9SChristopher Bostic } 128ac0385d9SChristopher Bostic 129ac0385d9SChristopher Bostic static void serial_out(struct fsi_master_gpio *master, 130ac0385d9SChristopher Bostic const struct fsi_gpio_msg *cmd) 131ac0385d9SChristopher Bostic { 132ac0385d9SChristopher Bostic uint8_t bit; 133ac0385d9SChristopher Bostic uint64_t msg = ~cmd->msg; /* Data is active low */ 134ac0385d9SChristopher Bostic uint64_t sda_mask = 0x1ULL << (cmd->bits - 1); 135ac0385d9SChristopher Bostic uint64_t last_bit = ~0; 136ac0385d9SChristopher Bostic int next_bit; 137ac0385d9SChristopher Bostic 1381247cf7aSJeremy Kerr trace_fsi_master_gpio_out(master, cmd->bits, cmd->msg); 1391247cf7aSJeremy Kerr 140ac0385d9SChristopher Bostic if (!cmd->bits) { 141ac0385d9SChristopher Bostic dev_warn(master->dev, "trying to output 0 bits\n"); 142ac0385d9SChristopher Bostic return; 143ac0385d9SChristopher Bostic } 144ac0385d9SChristopher Bostic set_sda_output(master, 0); 145ac0385d9SChristopher Bostic 146ac0385d9SChristopher Bostic /* Send the start bit */ 147ac0385d9SChristopher Bostic sda_out(master, 0); 148ac0385d9SChristopher Bostic clock_toggle(master, 1); 149ac0385d9SChristopher Bostic 150ac0385d9SChristopher Bostic /* Send the message */ 151ac0385d9SChristopher Bostic for (bit = 0; bit < cmd->bits; bit++) { 152ac0385d9SChristopher Bostic next_bit = (msg & sda_mask) >> (cmd->bits - 1); 153ac0385d9SChristopher Bostic if (last_bit ^ next_bit) { 154ac0385d9SChristopher Bostic sda_out(master, next_bit); 155ac0385d9SChristopher Bostic last_bit = next_bit; 156ac0385d9SChristopher Bostic } 157ac0385d9SChristopher Bostic clock_toggle(master, 1); 158ac0385d9SChristopher Bostic msg <<= 1; 159ac0385d9SChristopher Bostic } 160ac0385d9SChristopher Bostic } 161ac0385d9SChristopher Bostic 162ac0385d9SChristopher Bostic static void msg_push_bits(struct fsi_gpio_msg *msg, uint64_t data, int bits) 163ac0385d9SChristopher Bostic { 164ac0385d9SChristopher Bostic msg->msg <<= bits; 165ac0385d9SChristopher Bostic msg->msg |= data & ((1ull << bits) - 1); 166ac0385d9SChristopher Bostic msg->bits += bits; 167ac0385d9SChristopher Bostic } 168ac0385d9SChristopher Bostic 169ac0385d9SChristopher Bostic static void msg_push_crc(struct fsi_gpio_msg *msg) 170ac0385d9SChristopher Bostic { 171ac0385d9SChristopher Bostic uint8_t crc; 172ac0385d9SChristopher Bostic int top; 173ac0385d9SChristopher Bostic 174ac0385d9SChristopher Bostic top = msg->bits & 0x3; 175ac0385d9SChristopher Bostic 176ac0385d9SChristopher Bostic /* start bit, and any non-aligned top bits */ 177ac0385d9SChristopher Bostic crc = crc4(0, 1 << top | msg->msg >> (msg->bits - top), top + 1); 178ac0385d9SChristopher Bostic 179ac0385d9SChristopher Bostic /* aligned bits */ 180ac0385d9SChristopher Bostic crc = crc4(crc, msg->msg, msg->bits - top); 181ac0385d9SChristopher Bostic 182ac0385d9SChristopher Bostic msg_push_bits(msg, crc, 4); 183ac0385d9SChristopher Bostic } 184ac0385d9SChristopher Bostic 1850e82e5c1SJeremy Kerr static bool check_same_address(struct fsi_master_gpio *master, int id, 1860e82e5c1SJeremy Kerr uint32_t addr) 187ac0385d9SChristopher Bostic { 1880e82e5c1SJeremy Kerr /* this will also handle LAST_ADDR_INVALID */ 1890e82e5c1SJeremy Kerr return master->last_addr == (((id & 0x3) << 21) | (addr & ~0x3)); 1900e82e5c1SJeremy Kerr } 1910e82e5c1SJeremy Kerr 1920e82e5c1SJeremy Kerr static bool check_relative_address(struct fsi_master_gpio *master, int id, 1930e82e5c1SJeremy Kerr uint32_t addr, uint32_t *rel_addrp) 1940e82e5c1SJeremy Kerr { 1950e82e5c1SJeremy Kerr uint32_t last_addr = master->last_addr; 1960e82e5c1SJeremy Kerr int32_t rel_addr; 1970e82e5c1SJeremy Kerr 1980e82e5c1SJeremy Kerr if (last_addr == LAST_ADDR_INVALID) 1990e82e5c1SJeremy Kerr return false; 2000e82e5c1SJeremy Kerr 2010e82e5c1SJeremy Kerr /* We may be in 23-bit addressing mode, which uses the id as the 2020e82e5c1SJeremy Kerr * top two address bits. So, if we're referencing a different ID, 2030e82e5c1SJeremy Kerr * use absolute addresses. 2040e82e5c1SJeremy Kerr */ 2050e82e5c1SJeremy Kerr if (((last_addr >> 21) & 0x3) != id) 2060e82e5c1SJeremy Kerr return false; 2070e82e5c1SJeremy Kerr 2080e82e5c1SJeremy Kerr /* remove the top two bits from any 23-bit addressing */ 2090e82e5c1SJeremy Kerr last_addr &= (1 << 21) - 1; 2100e82e5c1SJeremy Kerr 2110e82e5c1SJeremy Kerr /* We know that the addresses are limited to 21 bits, so this won't 2120e82e5c1SJeremy Kerr * overflow the signed rel_addr */ 2130e82e5c1SJeremy Kerr rel_addr = addr - last_addr; 2140e82e5c1SJeremy Kerr if (rel_addr > 255 || rel_addr < -256) 2150e82e5c1SJeremy Kerr return false; 2160e82e5c1SJeremy Kerr 2170e82e5c1SJeremy Kerr *rel_addrp = (uint32_t)rel_addr; 2180e82e5c1SJeremy Kerr 2190e82e5c1SJeremy Kerr return true; 2200e82e5c1SJeremy Kerr } 2210e82e5c1SJeremy Kerr 2220e82e5c1SJeremy Kerr static void last_address_update(struct fsi_master_gpio *master, 2230e82e5c1SJeremy Kerr int id, bool valid, uint32_t addr) 2240e82e5c1SJeremy Kerr { 2250e82e5c1SJeremy Kerr if (!valid) 2260e82e5c1SJeremy Kerr master->last_addr = LAST_ADDR_INVALID; 2270e82e5c1SJeremy Kerr else 2280e82e5c1SJeremy Kerr master->last_addr = ((id & 0x3) << 21) | (addr & ~0x3); 2290e82e5c1SJeremy Kerr } 2300e82e5c1SJeremy Kerr 2310e82e5c1SJeremy Kerr /* 2320e82e5c1SJeremy Kerr * Encode an Absolute/Relative/Same Address command 2330e82e5c1SJeremy Kerr */ 2340e82e5c1SJeremy Kerr static void build_ar_command(struct fsi_master_gpio *master, 2350e82e5c1SJeremy Kerr struct fsi_gpio_msg *cmd, uint8_t id, 2360e82e5c1SJeremy Kerr uint32_t addr, size_t size, const void *data) 2370e82e5c1SJeremy Kerr { 2380e82e5c1SJeremy Kerr int i, addr_bits, opcode_bits; 239ac0385d9SChristopher Bostic bool write = !!data; 2400e82e5c1SJeremy Kerr uint8_t ds, opcode; 2410e82e5c1SJeremy Kerr uint32_t rel_addr; 242ac0385d9SChristopher Bostic 243ac0385d9SChristopher Bostic cmd->bits = 0; 244ac0385d9SChristopher Bostic cmd->msg = 0; 245ac0385d9SChristopher Bostic 2460e82e5c1SJeremy Kerr /* we have 21 bits of address max */ 2470e82e5c1SJeremy Kerr addr &= ((1 << 21) - 1); 2480e82e5c1SJeremy Kerr 2490e82e5c1SJeremy Kerr /* cmd opcodes are variable length - SAME_AR is only two bits */ 2500e82e5c1SJeremy Kerr opcode_bits = 3; 2510e82e5c1SJeremy Kerr 2520e82e5c1SJeremy Kerr if (check_same_address(master, id, addr)) { 2530e82e5c1SJeremy Kerr /* we still address the byte offset within the word */ 2540e82e5c1SJeremy Kerr addr_bits = 2; 2550e82e5c1SJeremy Kerr opcode_bits = 2; 25655382d30SBenjamin Herrenschmidt opcode = FSI_CMD_SAME_AR; 257777fd524SBenjamin Herrenschmidt trace_fsi_master_gpio_cmd_same_addr(master); 2580e82e5c1SJeremy Kerr 2590e82e5c1SJeremy Kerr } else if (check_relative_address(master, id, addr, &rel_addr)) { 2600e82e5c1SJeremy Kerr /* 8 bits plus sign */ 2610e82e5c1SJeremy Kerr addr_bits = 9; 2620e82e5c1SJeremy Kerr addr = rel_addr; 26355382d30SBenjamin Herrenschmidt opcode = FSI_CMD_REL_AR; 264777fd524SBenjamin Herrenschmidt trace_fsi_master_gpio_cmd_rel_addr(master, rel_addr); 2650e82e5c1SJeremy Kerr 2660e82e5c1SJeremy Kerr } else { 2670e82e5c1SJeremy Kerr addr_bits = 21; 26855382d30SBenjamin Herrenschmidt opcode = FSI_CMD_ABS_AR; 269777fd524SBenjamin Herrenschmidt trace_fsi_master_gpio_cmd_abs_addr(master, addr); 2700e82e5c1SJeremy Kerr } 271ac0385d9SChristopher Bostic 272ac0385d9SChristopher Bostic /* 273ac0385d9SChristopher Bostic * The read/write size is encoded in the lower bits of the address 274ac0385d9SChristopher Bostic * (as it must be naturally-aligned), and the following ds bit. 275ac0385d9SChristopher Bostic * 276ac0385d9SChristopher Bostic * size addr:1 addr:0 ds 277ac0385d9SChristopher Bostic * 1 x x 0 278ac0385d9SChristopher Bostic * 2 x 0 1 279ac0385d9SChristopher Bostic * 4 0 1 1 280ac0385d9SChristopher Bostic * 281ac0385d9SChristopher Bostic */ 282ac0385d9SChristopher Bostic ds = size > 1 ? 1 : 0; 283ac0385d9SChristopher Bostic addr &= ~(size - 1); 284ac0385d9SChristopher Bostic if (size == 4) 285ac0385d9SChristopher Bostic addr |= 1; 286ac0385d9SChristopher Bostic 2870e82e5c1SJeremy Kerr msg_push_bits(cmd, id, 2); 2880e82e5c1SJeremy Kerr msg_push_bits(cmd, opcode, opcode_bits); 2890e82e5c1SJeremy Kerr msg_push_bits(cmd, write ? 0 : 1, 1); 2900e82e5c1SJeremy Kerr msg_push_bits(cmd, addr, addr_bits); 291ac0385d9SChristopher Bostic msg_push_bits(cmd, ds, 1); 292ac0385d9SChristopher Bostic for (i = 0; write && i < size; i++) 293ac0385d9SChristopher Bostic msg_push_bits(cmd, ((uint8_t *)data)[i], 8); 294ac0385d9SChristopher Bostic 295ac0385d9SChristopher Bostic msg_push_crc(cmd); 296ac0385d9SChristopher Bostic } 297ac0385d9SChristopher Bostic 298ac0385d9SChristopher Bostic static void build_dpoll_command(struct fsi_gpio_msg *cmd, uint8_t slave_id) 299ac0385d9SChristopher Bostic { 300ac0385d9SChristopher Bostic cmd->bits = 0; 301ac0385d9SChristopher Bostic cmd->msg = 0; 302ac0385d9SChristopher Bostic 303ac0385d9SChristopher Bostic msg_push_bits(cmd, slave_id, 2); 30455382d30SBenjamin Herrenschmidt msg_push_bits(cmd, FSI_CMD_DPOLL, 3); 305ac0385d9SChristopher Bostic msg_push_crc(cmd); 306ac0385d9SChristopher Bostic } 307ac0385d9SChristopher Bostic 3084e56828aSBenjamin Herrenschmidt static void build_epoll_command(struct fsi_gpio_msg *cmd, uint8_t slave_id) 3094e56828aSBenjamin Herrenschmidt { 3104e56828aSBenjamin Herrenschmidt cmd->bits = 0; 3114e56828aSBenjamin Herrenschmidt cmd->msg = 0; 3124e56828aSBenjamin Herrenschmidt 3134e56828aSBenjamin Herrenschmidt msg_push_bits(cmd, slave_id, 2); 31455382d30SBenjamin Herrenschmidt msg_push_bits(cmd, FSI_CMD_EPOLL, 3); 3154e56828aSBenjamin Herrenschmidt msg_push_crc(cmd); 3164e56828aSBenjamin Herrenschmidt } 3174e56828aSBenjamin Herrenschmidt 318ac0385d9SChristopher Bostic static void build_term_command(struct fsi_gpio_msg *cmd, uint8_t slave_id) 319ac0385d9SChristopher Bostic { 320ac0385d9SChristopher Bostic cmd->bits = 0; 321ac0385d9SChristopher Bostic cmd->msg = 0; 322ac0385d9SChristopher Bostic 323ac0385d9SChristopher Bostic msg_push_bits(cmd, slave_id, 2); 32455382d30SBenjamin Herrenschmidt msg_push_bits(cmd, FSI_CMD_TERM, 6); 325ac0385d9SChristopher Bostic msg_push_crc(cmd); 326ac0385d9SChristopher Bostic } 327ac0385d9SChristopher Bostic 328ac0385d9SChristopher Bostic /* 3294e56828aSBenjamin Herrenschmidt * Note: callers rely specifically on this returning -EAGAIN for 3304e56828aSBenjamin Herrenschmidt * a CRC error detected in the response. Use other error code 3314e56828aSBenjamin Herrenschmidt * for other situations. It will be converted to something else 3324e56828aSBenjamin Herrenschmidt * higher up the stack before it reaches userspace. 3334e56828aSBenjamin Herrenschmidt */ 334ac0385d9SChristopher Bostic static int read_one_response(struct fsi_master_gpio *master, 335ac0385d9SChristopher Bostic uint8_t data_size, struct fsi_gpio_msg *msgp, uint8_t *tagp) 336ac0385d9SChristopher Bostic { 337ac0385d9SChristopher Bostic struct fsi_gpio_msg msg; 338e5538139SJeremy Kerr unsigned long flags; 339ac0385d9SChristopher Bostic uint32_t crc; 340e5538139SJeremy Kerr uint8_t tag; 341ac0385d9SChristopher Bostic int i; 342ac0385d9SChristopher Bostic 34326d79b27SJeremy Kerr local_irq_save(flags); 344e5538139SJeremy Kerr 345ac0385d9SChristopher Bostic /* wait for the start bit */ 34655382d30SBenjamin Herrenschmidt for (i = 0; i < FSI_MASTER_MTOE_COUNT; i++) { 347ac0385d9SChristopher Bostic msg.bits = 0; 348ac0385d9SChristopher Bostic msg.msg = 0; 349ac0385d9SChristopher Bostic serial_in(master, &msg, 1); 350ac0385d9SChristopher Bostic if (msg.msg) 351ac0385d9SChristopher Bostic break; 352ac0385d9SChristopher Bostic } 35355382d30SBenjamin Herrenschmidt if (i == FSI_MASTER_MTOE_COUNT) { 354ac0385d9SChristopher Bostic dev_dbg(master->dev, 355ac0385d9SChristopher Bostic "Master time out waiting for response\n"); 35626d79b27SJeremy Kerr local_irq_restore(flags); 3574e56828aSBenjamin Herrenschmidt return -ETIMEDOUT; 358ac0385d9SChristopher Bostic } 359ac0385d9SChristopher Bostic 360ac0385d9SChristopher Bostic msg.bits = 0; 361ac0385d9SChristopher Bostic msg.msg = 0; 362ac0385d9SChristopher Bostic 363ac0385d9SChristopher Bostic /* Read slave ID & response tag */ 364ac0385d9SChristopher Bostic serial_in(master, &msg, 4); 365ac0385d9SChristopher Bostic 366ac0385d9SChristopher Bostic tag = msg.msg & 0x3; 367ac0385d9SChristopher Bostic 368ac0385d9SChristopher Bostic /* If we have an ACK and we're expecting data, clock the data in too */ 36955382d30SBenjamin Herrenschmidt if (tag == FSI_RESP_ACK && data_size) 370ac0385d9SChristopher Bostic serial_in(master, &msg, data_size * 8); 371ac0385d9SChristopher Bostic 372ac0385d9SChristopher Bostic /* read CRC */ 37355382d30SBenjamin Herrenschmidt serial_in(master, &msg, FSI_CRC_SIZE); 374ac0385d9SChristopher Bostic 37526d79b27SJeremy Kerr local_irq_restore(flags); 376e5538139SJeremy Kerr 377ac0385d9SChristopher Bostic /* we have a whole message now; check CRC */ 378ac0385d9SChristopher Bostic crc = crc4(0, 1, 1); 379ac0385d9SChristopher Bostic crc = crc4(crc, msg.msg, msg.bits); 380ac0385d9SChristopher Bostic if (crc) { 381c49e3440SBenjamin Herrenschmidt /* Check if it's all 1's, that probably means the host is off */ 382c49e3440SBenjamin Herrenschmidt if (((~msg.msg) & ((1ull << msg.bits) - 1)) == 0) 383c49e3440SBenjamin Herrenschmidt return -ENODEV; 384c49e3440SBenjamin Herrenschmidt dev_dbg(master->dev, "ERR response CRC msg: 0x%016llx (%d bits)\n", 385c49e3440SBenjamin Herrenschmidt msg.msg, msg.bits); 3864e56828aSBenjamin Herrenschmidt return -EAGAIN; 387ac0385d9SChristopher Bostic } 388ac0385d9SChristopher Bostic 389ac0385d9SChristopher Bostic if (msgp) 390ac0385d9SChristopher Bostic *msgp = msg; 391ac0385d9SChristopher Bostic if (tagp) 392ac0385d9SChristopher Bostic *tagp = tag; 393ac0385d9SChristopher Bostic 394ac0385d9SChristopher Bostic return 0; 395ac0385d9SChristopher Bostic } 396ac0385d9SChristopher Bostic 397ac0385d9SChristopher Bostic static int issue_term(struct fsi_master_gpio *master, uint8_t slave) 398ac0385d9SChristopher Bostic { 399ac0385d9SChristopher Bostic struct fsi_gpio_msg cmd; 400e5538139SJeremy Kerr unsigned long flags; 401ac0385d9SChristopher Bostic uint8_t tag; 402ac0385d9SChristopher Bostic int rc; 403ac0385d9SChristopher Bostic 404ac0385d9SChristopher Bostic build_term_command(&cmd, slave); 405e5538139SJeremy Kerr 40626d79b27SJeremy Kerr local_irq_save(flags); 407ac0385d9SChristopher Bostic serial_out(master, &cmd); 408ac0385d9SChristopher Bostic echo_delay(master); 40926d79b27SJeremy Kerr local_irq_restore(flags); 410ac0385d9SChristopher Bostic 411ac0385d9SChristopher Bostic rc = read_one_response(master, 0, NULL, &tag); 412ac0385d9SChristopher Bostic if (rc < 0) { 413ac0385d9SChristopher Bostic dev_err(master->dev, 414ac0385d9SChristopher Bostic "TERM failed; lost communication with slave\n"); 415ac0385d9SChristopher Bostic return -EIO; 41655382d30SBenjamin Herrenschmidt } else if (tag != FSI_RESP_ACK) { 417ac0385d9SChristopher Bostic dev_err(master->dev, "TERM failed; response %d\n", tag); 418ac0385d9SChristopher Bostic return -EIO; 419ac0385d9SChristopher Bostic } 420ac0385d9SChristopher Bostic 421ac0385d9SChristopher Bostic return 0; 422ac0385d9SChristopher Bostic } 423ac0385d9SChristopher Bostic 424ac0385d9SChristopher Bostic static int poll_for_response(struct fsi_master_gpio *master, 425ac0385d9SChristopher Bostic uint8_t slave, uint8_t size, void *data) 426ac0385d9SChristopher Bostic { 427ac0385d9SChristopher Bostic struct fsi_gpio_msg response, cmd; 428ac0385d9SChristopher Bostic int busy_count = 0, rc, i; 429e5538139SJeremy Kerr unsigned long flags; 430ac0385d9SChristopher Bostic uint8_t tag; 431ac0385d9SChristopher Bostic uint8_t *data_byte = data; 4324e56828aSBenjamin Herrenschmidt int crc_err_retries = 0; 433ac0385d9SChristopher Bostic retry: 434ac0385d9SChristopher Bostic rc = read_one_response(master, size, &response, &tag); 4354e56828aSBenjamin Herrenschmidt 4364e56828aSBenjamin Herrenschmidt /* Handle retries on CRC errors */ 4374e56828aSBenjamin Herrenschmidt if (rc == -EAGAIN) { 4384e56828aSBenjamin Herrenschmidt /* Too many retries ? */ 4394e56828aSBenjamin Herrenschmidt if (crc_err_retries++ > FSI_CRC_ERR_RETRIES) { 4404e56828aSBenjamin Herrenschmidt /* 4414e56828aSBenjamin Herrenschmidt * Pass it up as a -EIO otherwise upper level will retry 4424e56828aSBenjamin Herrenschmidt * the whole command which isn't what we want here. 4434e56828aSBenjamin Herrenschmidt */ 4444e56828aSBenjamin Herrenschmidt rc = -EIO; 4454e56828aSBenjamin Herrenschmidt goto fail; 4464e56828aSBenjamin Herrenschmidt } 4474e56828aSBenjamin Herrenschmidt dev_dbg(master->dev, 4484e56828aSBenjamin Herrenschmidt "CRC error retry %d\n", crc_err_retries); 4494e56828aSBenjamin Herrenschmidt trace_fsi_master_gpio_crc_rsp_error(master); 4504e56828aSBenjamin Herrenschmidt build_epoll_command(&cmd, slave); 45126d79b27SJeremy Kerr local_irq_save(flags); 45255382d30SBenjamin Herrenschmidt clock_zeros(master, FSI_MASTER_EPOLL_CLOCKS); 4534e56828aSBenjamin Herrenschmidt serial_out(master, &cmd); 4544e56828aSBenjamin Herrenschmidt echo_delay(master); 45526d79b27SJeremy Kerr local_irq_restore(flags); 4564e56828aSBenjamin Herrenschmidt goto retry; 4574e56828aSBenjamin Herrenschmidt } else if (rc) 4584e56828aSBenjamin Herrenschmidt goto fail; 459ac0385d9SChristopher Bostic 460ac0385d9SChristopher Bostic switch (tag) { 46155382d30SBenjamin Herrenschmidt case FSI_RESP_ACK: 462ac0385d9SChristopher Bostic if (size && data) { 463ac0385d9SChristopher Bostic uint64_t val = response.msg; 464ac0385d9SChristopher Bostic /* clear crc & mask */ 465ac0385d9SChristopher Bostic val >>= 4; 466ac0385d9SChristopher Bostic val &= (1ull << (size * 8)) - 1; 467ac0385d9SChristopher Bostic 468ac0385d9SChristopher Bostic for (i = 0; i < size; i++) { 469ac0385d9SChristopher Bostic data_byte[size-i-1] = val; 470ac0385d9SChristopher Bostic val >>= 8; 471ac0385d9SChristopher Bostic } 472ac0385d9SChristopher Bostic } 473ac0385d9SChristopher Bostic break; 47455382d30SBenjamin Herrenschmidt case FSI_RESP_BUSY: 475ac0385d9SChristopher Bostic /* 476ac0385d9SChristopher Bostic * Its necessary to clock slave before issuing 477ac0385d9SChristopher Bostic * d-poll, not indicated in the hardware protocol 478ac0385d9SChristopher Bostic * spec. < 20 clocks causes slave to hang, 21 ok. 479ac0385d9SChristopher Bostic */ 48055382d30SBenjamin Herrenschmidt if (busy_count++ < FSI_MASTER_MAX_BUSY) { 481ac0385d9SChristopher Bostic build_dpoll_command(&cmd, slave); 48226d79b27SJeremy Kerr local_irq_save(flags); 48355382d30SBenjamin Herrenschmidt clock_zeros(master, FSI_MASTER_DPOLL_CLOCKS); 484ac0385d9SChristopher Bostic serial_out(master, &cmd); 485ac0385d9SChristopher Bostic echo_delay(master); 48626d79b27SJeremy Kerr local_irq_restore(flags); 487ac0385d9SChristopher Bostic goto retry; 488ac0385d9SChristopher Bostic } 489ac0385d9SChristopher Bostic dev_warn(master->dev, 490ac0385d9SChristopher Bostic "ERR slave is stuck in busy state, issuing TERM\n"); 49126d79b27SJeremy Kerr local_irq_save(flags); 49255382d30SBenjamin Herrenschmidt clock_zeros(master, FSI_MASTER_DPOLL_CLOCKS); 49326d79b27SJeremy Kerr local_irq_restore(flags); 494ac0385d9SChristopher Bostic issue_term(master, slave); 495ac0385d9SChristopher Bostic rc = -EIO; 496ac0385d9SChristopher Bostic break; 497ac0385d9SChristopher Bostic 49855382d30SBenjamin Herrenschmidt case FSI_RESP_ERRA: 4994e56828aSBenjamin Herrenschmidt dev_dbg(master->dev, "ERRA received: 0x%x\n", (int)response.msg); 500ac0385d9SChristopher Bostic rc = -EIO; 501ac0385d9SChristopher Bostic break; 50255382d30SBenjamin Herrenschmidt case FSI_RESP_ERRC: 5034e56828aSBenjamin Herrenschmidt dev_dbg(master->dev, "ERRC received: 0x%x\n", (int)response.msg); 5044e56828aSBenjamin Herrenschmidt trace_fsi_master_gpio_crc_cmd_error(master); 5054e56828aSBenjamin Herrenschmidt rc = -EAGAIN; 5064e56828aSBenjamin Herrenschmidt break; 507ac0385d9SChristopher Bostic } 508ac0385d9SChristopher Bostic 509918da951SAndrew Jeffery if (busy_count > 0) 510918da951SAndrew Jeffery trace_fsi_master_gpio_poll_response_busy(master, busy_count); 5114e56828aSBenjamin Herrenschmidt fail: 512edc24851SBenjamin Herrenschmidt /* 513edc24851SBenjamin Herrenschmidt * tSendDelay clocks, avoids signal reflections when switching 514edc24851SBenjamin Herrenschmidt * from receive of response back to send of data. 515edc24851SBenjamin Herrenschmidt */ 51626d79b27SJeremy Kerr local_irq_save(flags); 51775854c14SBenjamin Herrenschmidt clock_zeros(master, master->t_send_delay); 51826d79b27SJeremy Kerr local_irq_restore(flags); 51926d79b27SJeremy Kerr 520ac0385d9SChristopher Bostic return rc; 521ac0385d9SChristopher Bostic } 522ac0385d9SChristopher Bostic 523e5538139SJeremy Kerr static int send_request(struct fsi_master_gpio *master, 524e5538139SJeremy Kerr struct fsi_gpio_msg *cmd) 525ac0385d9SChristopher Bostic { 526ac0385d9SChristopher Bostic unsigned long flags; 527ac0385d9SChristopher Bostic 52826d79b27SJeremy Kerr if (master->external_mode) 529b8bd146dSJeremy Kerr return -EBUSY; 530b8bd146dSJeremy Kerr 53126d79b27SJeremy Kerr local_irq_save(flags); 532ac0385d9SChristopher Bostic serial_out(master, cmd); 533ac0385d9SChristopher Bostic echo_delay(master); 53426d79b27SJeremy Kerr local_irq_restore(flags); 535e5538139SJeremy Kerr 536e5538139SJeremy Kerr return 0; 537e5538139SJeremy Kerr } 538e5538139SJeremy Kerr 539e5538139SJeremy Kerr static int fsi_master_gpio_xfer(struct fsi_master_gpio *master, uint8_t slave, 540e5538139SJeremy Kerr struct fsi_gpio_msg *cmd, size_t resp_len, void *resp) 541e5538139SJeremy Kerr { 5424e56828aSBenjamin Herrenschmidt int rc = -EAGAIN, retries = 0; 543e5538139SJeremy Kerr 5444e56828aSBenjamin Herrenschmidt while ((retries++) < FSI_CRC_ERR_RETRIES) { 545e5538139SJeremy Kerr rc = send_request(master, cmd); 5464e56828aSBenjamin Herrenschmidt if (rc) 5474e56828aSBenjamin Herrenschmidt break; 548ac0385d9SChristopher Bostic rc = poll_for_response(master, slave, resp_len, resp); 5494e56828aSBenjamin Herrenschmidt if (rc != -EAGAIN) 5504e56828aSBenjamin Herrenschmidt break; 5514e56828aSBenjamin Herrenschmidt rc = -EIO; 5524e56828aSBenjamin Herrenschmidt dev_warn(master->dev, "ECRC retry %d\n", retries); 5534e56828aSBenjamin Herrenschmidt 5544e56828aSBenjamin Herrenschmidt /* Pace it a bit before retry */ 5554e56828aSBenjamin Herrenschmidt msleep(1); 5564e56828aSBenjamin Herrenschmidt } 557e5538139SJeremy Kerr 558ac0385d9SChristopher Bostic return rc; 559ac0385d9SChristopher Bostic } 560ac0385d9SChristopher Bostic 561ac0385d9SChristopher Bostic static int fsi_master_gpio_read(struct fsi_master *_master, int link, 562ac0385d9SChristopher Bostic uint8_t id, uint32_t addr, void *val, size_t size) 563ac0385d9SChristopher Bostic { 564ac0385d9SChristopher Bostic struct fsi_master_gpio *master = to_fsi_master_gpio(_master); 565ac0385d9SChristopher Bostic struct fsi_gpio_msg cmd; 5668193fb44SJeremy Kerr int rc; 567ac0385d9SChristopher Bostic 568ac0385d9SChristopher Bostic if (link != 0) 569ac0385d9SChristopher Bostic return -ENODEV; 570ac0385d9SChristopher Bostic 5718193fb44SJeremy Kerr mutex_lock(&master->cmd_lock); 5720e82e5c1SJeremy Kerr build_ar_command(master, &cmd, id, addr, size, NULL); 5738193fb44SJeremy Kerr rc = fsi_master_gpio_xfer(master, id, &cmd, size, val); 5740e82e5c1SJeremy Kerr last_address_update(master, id, rc == 0, addr); 5758193fb44SJeremy Kerr mutex_unlock(&master->cmd_lock); 5768193fb44SJeremy Kerr 5778193fb44SJeremy Kerr return rc; 578ac0385d9SChristopher Bostic } 579ac0385d9SChristopher Bostic 580ac0385d9SChristopher Bostic static int fsi_master_gpio_write(struct fsi_master *_master, int link, 581ac0385d9SChristopher Bostic uint8_t id, uint32_t addr, const void *val, size_t size) 582ac0385d9SChristopher Bostic { 583ac0385d9SChristopher Bostic struct fsi_master_gpio *master = to_fsi_master_gpio(_master); 584ac0385d9SChristopher Bostic struct fsi_gpio_msg cmd; 5858193fb44SJeremy Kerr int rc; 586ac0385d9SChristopher Bostic 587ac0385d9SChristopher Bostic if (link != 0) 588ac0385d9SChristopher Bostic return -ENODEV; 589ac0385d9SChristopher Bostic 5908193fb44SJeremy Kerr mutex_lock(&master->cmd_lock); 5910e82e5c1SJeremy Kerr build_ar_command(master, &cmd, id, addr, size, val); 5928193fb44SJeremy Kerr rc = fsi_master_gpio_xfer(master, id, &cmd, 0, NULL); 5930e82e5c1SJeremy Kerr last_address_update(master, id, rc == 0, addr); 5948193fb44SJeremy Kerr mutex_unlock(&master->cmd_lock); 5958193fb44SJeremy Kerr 5968193fb44SJeremy Kerr return rc; 597ac0385d9SChristopher Bostic } 598ac0385d9SChristopher Bostic 599ac0385d9SChristopher Bostic static int fsi_master_gpio_term(struct fsi_master *_master, 600ac0385d9SChristopher Bostic int link, uint8_t id) 601ac0385d9SChristopher Bostic { 602ac0385d9SChristopher Bostic struct fsi_master_gpio *master = to_fsi_master_gpio(_master); 603ac0385d9SChristopher Bostic struct fsi_gpio_msg cmd; 6048193fb44SJeremy Kerr int rc; 605ac0385d9SChristopher Bostic 606ac0385d9SChristopher Bostic if (link != 0) 607ac0385d9SChristopher Bostic return -ENODEV; 608ac0385d9SChristopher Bostic 6098193fb44SJeremy Kerr mutex_lock(&master->cmd_lock); 610ac0385d9SChristopher Bostic build_term_command(&cmd, id); 6118193fb44SJeremy Kerr rc = fsi_master_gpio_xfer(master, id, &cmd, 0, NULL); 6120e82e5c1SJeremy Kerr last_address_update(master, id, false, 0); 6138193fb44SJeremy Kerr mutex_unlock(&master->cmd_lock); 6148193fb44SJeremy Kerr 6158193fb44SJeremy Kerr return rc; 616ac0385d9SChristopher Bostic } 617ac0385d9SChristopher Bostic 618ac0385d9SChristopher Bostic static int fsi_master_gpio_break(struct fsi_master *_master, int link) 619ac0385d9SChristopher Bostic { 620ac0385d9SChristopher Bostic struct fsi_master_gpio *master = to_fsi_master_gpio(_master); 62129d9b927SJeremy Kerr unsigned long flags; 622ac0385d9SChristopher Bostic 623ac0385d9SChristopher Bostic if (link != 0) 624ac0385d9SChristopher Bostic return -ENODEV; 625ac0385d9SChristopher Bostic 6261247cf7aSJeremy Kerr trace_fsi_master_gpio_break(master); 6271247cf7aSJeremy Kerr 628e5538139SJeremy Kerr mutex_lock(&master->cmd_lock); 629b8bd146dSJeremy Kerr if (master->external_mode) { 630e5538139SJeremy Kerr mutex_unlock(&master->cmd_lock); 631b8bd146dSJeremy Kerr return -EBUSY; 632b8bd146dSJeremy Kerr } 633e5538139SJeremy Kerr 63426d79b27SJeremy Kerr local_irq_save(flags); 635e5538139SJeremy Kerr 636ac0385d9SChristopher Bostic set_sda_output(master, 1); 637ac0385d9SChristopher Bostic sda_out(master, 1); 638ac0385d9SChristopher Bostic clock_toggle(master, FSI_PRE_BREAK_CLOCKS); 639ac0385d9SChristopher Bostic sda_out(master, 0); 640ac0385d9SChristopher Bostic clock_toggle(master, FSI_BREAK_CLOCKS); 641ac0385d9SChristopher Bostic echo_delay(master); 642ac0385d9SChristopher Bostic sda_out(master, 1); 643ac0385d9SChristopher Bostic clock_toggle(master, FSI_POST_BREAK_CLOCKS); 644e5538139SJeremy Kerr 64526d79b27SJeremy Kerr local_irq_restore(flags); 64626d79b27SJeremy Kerr 6470e82e5c1SJeremy Kerr last_address_update(master, 0, false, 0); 648e5538139SJeremy Kerr mutex_unlock(&master->cmd_lock); 649ac0385d9SChristopher Bostic 650ac0385d9SChristopher Bostic /* Wait for logic reset to take effect */ 651ac0385d9SChristopher Bostic udelay(200); 652ac0385d9SChristopher Bostic 653ac0385d9SChristopher Bostic return 0; 654ac0385d9SChristopher Bostic } 655ac0385d9SChristopher Bostic 656ac0385d9SChristopher Bostic static void fsi_master_gpio_init(struct fsi_master_gpio *master) 657ac0385d9SChristopher Bostic { 658e5538139SJeremy Kerr unsigned long flags; 659e5538139SJeremy Kerr 660ac0385d9SChristopher Bostic gpiod_direction_output(master->gpio_mux, 1); 661ac0385d9SChristopher Bostic gpiod_direction_output(master->gpio_trans, 1); 662ac0385d9SChristopher Bostic gpiod_direction_output(master->gpio_enable, 1); 663ac0385d9SChristopher Bostic gpiod_direction_output(master->gpio_clk, 1); 664ac0385d9SChristopher Bostic gpiod_direction_output(master->gpio_data, 1); 665ac0385d9SChristopher Bostic 666ac0385d9SChristopher Bostic /* todo: evaluate if clocks can be reduced */ 66726d79b27SJeremy Kerr local_irq_save(flags); 668ac0385d9SChristopher Bostic clock_zeros(master, FSI_INIT_CLOCKS); 66926d79b27SJeremy Kerr local_irq_restore(flags); 670ac0385d9SChristopher Bostic } 671ac0385d9SChristopher Bostic 672b8bd146dSJeremy Kerr static void fsi_master_gpio_init_external(struct fsi_master_gpio *master) 673b8bd146dSJeremy Kerr { 674b8bd146dSJeremy Kerr gpiod_direction_output(master->gpio_mux, 0); 675b8bd146dSJeremy Kerr gpiod_direction_output(master->gpio_trans, 0); 676b8bd146dSJeremy Kerr gpiod_direction_output(master->gpio_enable, 1); 677b8bd146dSJeremy Kerr gpiod_direction_input(master->gpio_clk); 678b8bd146dSJeremy Kerr gpiod_direction_input(master->gpio_data); 679b8bd146dSJeremy Kerr } 680b8bd146dSJeremy Kerr 68104635a30SEddie James static int fsi_master_gpio_link_enable(struct fsi_master *_master, int link, 68204635a30SEddie James bool enable) 683ac0385d9SChristopher Bostic { 684ac0385d9SChristopher Bostic struct fsi_master_gpio *master = to_fsi_master_gpio(_master); 685b8bd146dSJeremy Kerr int rc = -EBUSY; 686ac0385d9SChristopher Bostic 687ac0385d9SChristopher Bostic if (link != 0) 688ac0385d9SChristopher Bostic return -ENODEV; 68929d9b927SJeremy Kerr 690e5538139SJeremy Kerr mutex_lock(&master->cmd_lock); 691b8bd146dSJeremy Kerr if (!master->external_mode) { 69204635a30SEddie James gpiod_set_value(master->gpio_enable, enable ? 1 : 0); 693b8bd146dSJeremy Kerr rc = 0; 694b8bd146dSJeremy Kerr } 695e5538139SJeremy Kerr mutex_unlock(&master->cmd_lock); 696ac0385d9SChristopher Bostic 697b8bd146dSJeremy Kerr return rc; 698ac0385d9SChristopher Bostic } 699ac0385d9SChristopher Bostic 70075854c14SBenjamin Herrenschmidt static int fsi_master_gpio_link_config(struct fsi_master *_master, int link, 70175854c14SBenjamin Herrenschmidt u8 t_send_delay, u8 t_echo_delay) 70275854c14SBenjamin Herrenschmidt { 70375854c14SBenjamin Herrenschmidt struct fsi_master_gpio *master = to_fsi_master_gpio(_master); 70475854c14SBenjamin Herrenschmidt 70575854c14SBenjamin Herrenschmidt if (link != 0) 70675854c14SBenjamin Herrenschmidt return -ENODEV; 70775854c14SBenjamin Herrenschmidt 70875854c14SBenjamin Herrenschmidt mutex_lock(&master->cmd_lock); 70975854c14SBenjamin Herrenschmidt master->t_send_delay = t_send_delay; 71075854c14SBenjamin Herrenschmidt master->t_echo_delay = t_echo_delay; 71175854c14SBenjamin Herrenschmidt mutex_unlock(&master->cmd_lock); 71275854c14SBenjamin Herrenschmidt 71375854c14SBenjamin Herrenschmidt return 0; 71475854c14SBenjamin Herrenschmidt } 71575854c14SBenjamin Herrenschmidt 716b8bd146dSJeremy Kerr static ssize_t external_mode_show(struct device *dev, 717b8bd146dSJeremy Kerr struct device_attribute *attr, char *buf) 718b8bd146dSJeremy Kerr { 719b8bd146dSJeremy Kerr struct fsi_master_gpio *master = dev_get_drvdata(dev); 720b8bd146dSJeremy Kerr 721b8bd146dSJeremy Kerr return snprintf(buf, PAGE_SIZE - 1, "%u\n", 722b8bd146dSJeremy Kerr master->external_mode ? 1 : 0); 723b8bd146dSJeremy Kerr } 724b8bd146dSJeremy Kerr 725b8bd146dSJeremy Kerr static ssize_t external_mode_store(struct device *dev, 726b8bd146dSJeremy Kerr struct device_attribute *attr, const char *buf, size_t count) 727b8bd146dSJeremy Kerr { 728b8bd146dSJeremy Kerr struct fsi_master_gpio *master = dev_get_drvdata(dev); 729e5538139SJeremy Kerr unsigned long val; 730b8bd146dSJeremy Kerr bool external_mode; 731b8bd146dSJeremy Kerr int err; 732b8bd146dSJeremy Kerr 733b8bd146dSJeremy Kerr err = kstrtoul(buf, 0, &val); 734b8bd146dSJeremy Kerr if (err) 735b8bd146dSJeremy Kerr return err; 736b8bd146dSJeremy Kerr 737b8bd146dSJeremy Kerr external_mode = !!val; 738b8bd146dSJeremy Kerr 739e5538139SJeremy Kerr mutex_lock(&master->cmd_lock); 740b8bd146dSJeremy Kerr 741b8bd146dSJeremy Kerr if (external_mode == master->external_mode) { 742e5538139SJeremy Kerr mutex_unlock(&master->cmd_lock); 743b8bd146dSJeremy Kerr return count; 744b8bd146dSJeremy Kerr } 745b8bd146dSJeremy Kerr 746b8bd146dSJeremy Kerr master->external_mode = external_mode; 747b8bd146dSJeremy Kerr if (master->external_mode) 748b8bd146dSJeremy Kerr fsi_master_gpio_init_external(master); 749b8bd146dSJeremy Kerr else 750b8bd146dSJeremy Kerr fsi_master_gpio_init(master); 751e5538139SJeremy Kerr 752e5538139SJeremy Kerr mutex_unlock(&master->cmd_lock); 753b8bd146dSJeremy Kerr 754b8bd146dSJeremy Kerr fsi_master_rescan(&master->master); 755b8bd146dSJeremy Kerr 756b8bd146dSJeremy Kerr return count; 757b8bd146dSJeremy Kerr } 758b8bd146dSJeremy Kerr 759b8bd146dSJeremy Kerr static DEVICE_ATTR(external_mode, 0664, 760b8bd146dSJeremy Kerr external_mode_show, external_mode_store); 761b8bd146dSJeremy Kerr 7628ef9ccf8SBenjamin Herrenschmidt static void fsi_master_gpio_release(struct device *dev) 7638ef9ccf8SBenjamin Herrenschmidt { 7648ef9ccf8SBenjamin Herrenschmidt struct fsi_master_gpio *master = to_fsi_master_gpio(dev_to_fsi_master(dev)); 7658ef9ccf8SBenjamin Herrenschmidt 7668ef9ccf8SBenjamin Herrenschmidt of_node_put(dev_of_node(master->dev)); 7678ef9ccf8SBenjamin Herrenschmidt 7688ef9ccf8SBenjamin Herrenschmidt kfree(master); 7698ef9ccf8SBenjamin Herrenschmidt } 7708ef9ccf8SBenjamin Herrenschmidt 771ac0385d9SChristopher Bostic static int fsi_master_gpio_probe(struct platform_device *pdev) 772ac0385d9SChristopher Bostic { 773ac0385d9SChristopher Bostic struct fsi_master_gpio *master; 774ac0385d9SChristopher Bostic struct gpio_desc *gpio; 775b8bd146dSJeremy Kerr int rc; 776ac0385d9SChristopher Bostic 7778ef9ccf8SBenjamin Herrenschmidt master = kzalloc(sizeof(*master), GFP_KERNEL); 778ac0385d9SChristopher Bostic if (!master) 779ac0385d9SChristopher Bostic return -ENOMEM; 780ac0385d9SChristopher Bostic 781ac0385d9SChristopher Bostic master->dev = &pdev->dev; 782ac0385d9SChristopher Bostic master->master.dev.parent = master->dev; 783f6a2f8ebSJeremy Kerr master->master.dev.of_node = of_node_get(dev_of_node(master->dev)); 7848ef9ccf8SBenjamin Herrenschmidt master->master.dev.release = fsi_master_gpio_release; 7850e82e5c1SJeremy Kerr master->last_addr = LAST_ADDR_INVALID; 786ac0385d9SChristopher Bostic 787ac0385d9SChristopher Bostic gpio = devm_gpiod_get(&pdev->dev, "clock", 0); 788ac0385d9SChristopher Bostic if (IS_ERR(gpio)) { 789ac0385d9SChristopher Bostic dev_err(&pdev->dev, "failed to get clock gpio\n"); 7908ef9ccf8SBenjamin Herrenschmidt rc = PTR_ERR(gpio); 7918ef9ccf8SBenjamin Herrenschmidt goto err_free; 792ac0385d9SChristopher Bostic } 793ac0385d9SChristopher Bostic master->gpio_clk = gpio; 794ac0385d9SChristopher Bostic 795ac0385d9SChristopher Bostic gpio = devm_gpiod_get(&pdev->dev, "data", 0); 796ac0385d9SChristopher Bostic if (IS_ERR(gpio)) { 797ac0385d9SChristopher Bostic dev_err(&pdev->dev, "failed to get data gpio\n"); 7988ef9ccf8SBenjamin Herrenschmidt rc = PTR_ERR(gpio); 7998ef9ccf8SBenjamin Herrenschmidt goto err_free; 800ac0385d9SChristopher Bostic } 801ac0385d9SChristopher Bostic master->gpio_data = gpio; 802ac0385d9SChristopher Bostic 803ac0385d9SChristopher Bostic /* Optional GPIOs */ 804ac0385d9SChristopher Bostic gpio = devm_gpiod_get_optional(&pdev->dev, "trans", 0); 805ac0385d9SChristopher Bostic if (IS_ERR(gpio)) { 806ac0385d9SChristopher Bostic dev_err(&pdev->dev, "failed to get trans gpio\n"); 8078ef9ccf8SBenjamin Herrenschmidt rc = PTR_ERR(gpio); 8088ef9ccf8SBenjamin Herrenschmidt goto err_free; 809ac0385d9SChristopher Bostic } 810ac0385d9SChristopher Bostic master->gpio_trans = gpio; 811ac0385d9SChristopher Bostic 812ac0385d9SChristopher Bostic gpio = devm_gpiod_get_optional(&pdev->dev, "enable", 0); 813ac0385d9SChristopher Bostic if (IS_ERR(gpio)) { 814ac0385d9SChristopher Bostic dev_err(&pdev->dev, "failed to get enable gpio\n"); 8158ef9ccf8SBenjamin Herrenschmidt rc = PTR_ERR(gpio); 8168ef9ccf8SBenjamin Herrenschmidt goto err_free; 817ac0385d9SChristopher Bostic } 818ac0385d9SChristopher Bostic master->gpio_enable = gpio; 819ac0385d9SChristopher Bostic 820ac0385d9SChristopher Bostic gpio = devm_gpiod_get_optional(&pdev->dev, "mux", 0); 821ac0385d9SChristopher Bostic if (IS_ERR(gpio)) { 822ac0385d9SChristopher Bostic dev_err(&pdev->dev, "failed to get mux gpio\n"); 8238ef9ccf8SBenjamin Herrenschmidt rc = PTR_ERR(gpio); 8248ef9ccf8SBenjamin Herrenschmidt goto err_free; 825ac0385d9SChristopher Bostic } 826ac0385d9SChristopher Bostic master->gpio_mux = gpio; 827ac0385d9SChristopher Bostic 828bc1099d2SBenjamin Herrenschmidt /* 829bc1099d2SBenjamin Herrenschmidt * Check if GPIO block is slow enought that no extra delays 830bc1099d2SBenjamin Herrenschmidt * are necessary. This improves performance on ast2500 by 831bc1099d2SBenjamin Herrenschmidt * an order of magnitude. 832bc1099d2SBenjamin Herrenschmidt */ 833bc1099d2SBenjamin Herrenschmidt master->no_delays = device_property_present(&pdev->dev, "no-gpio-delays"); 834bc1099d2SBenjamin Herrenschmidt 83575854c14SBenjamin Herrenschmidt /* Default FSI command delays */ 83675854c14SBenjamin Herrenschmidt master->t_send_delay = FSI_SEND_DELAY_CLOCKS; 83775854c14SBenjamin Herrenschmidt master->t_echo_delay = FSI_ECHO_DELAY_CLOCKS; 83875854c14SBenjamin Herrenschmidt 839ac0385d9SChristopher Bostic master->master.n_links = 1; 8404af889b0SJeremy Kerr master->master.flags = FSI_MASTER_FLAG_SWCLOCK; 841ac0385d9SChristopher Bostic master->master.read = fsi_master_gpio_read; 842ac0385d9SChristopher Bostic master->master.write = fsi_master_gpio_write; 843ac0385d9SChristopher Bostic master->master.term = fsi_master_gpio_term; 844ac0385d9SChristopher Bostic master->master.send_break = fsi_master_gpio_break; 845ac0385d9SChristopher Bostic master->master.link_enable = fsi_master_gpio_link_enable; 84675854c14SBenjamin Herrenschmidt master->master.link_config = fsi_master_gpio_link_config; 847ac0385d9SChristopher Bostic platform_set_drvdata(pdev, master); 848e5538139SJeremy Kerr mutex_init(&master->cmd_lock); 849ac0385d9SChristopher Bostic 850ac0385d9SChristopher Bostic fsi_master_gpio_init(master); 851ac0385d9SChristopher Bostic 852b8bd146dSJeremy Kerr rc = device_create_file(&pdev->dev, &dev_attr_external_mode); 853b8bd146dSJeremy Kerr if (rc) 8548ef9ccf8SBenjamin Herrenschmidt goto err_free; 855b8bd146dSJeremy Kerr 8568ef9ccf8SBenjamin Herrenschmidt rc = fsi_master_register(&master->master); 8578ef9ccf8SBenjamin Herrenschmidt if (rc) { 8588ef9ccf8SBenjamin Herrenschmidt device_remove_file(&pdev->dev, &dev_attr_external_mode); 8598ef9ccf8SBenjamin Herrenschmidt put_device(&master->master.dev); 8608ef9ccf8SBenjamin Herrenschmidt return rc; 861ac0385d9SChristopher Bostic } 8628ef9ccf8SBenjamin Herrenschmidt return 0; 8638ef9ccf8SBenjamin Herrenschmidt err_free: 8648ef9ccf8SBenjamin Herrenschmidt kfree(master); 8658ef9ccf8SBenjamin Herrenschmidt return rc; 8668ef9ccf8SBenjamin Herrenschmidt } 8678ef9ccf8SBenjamin Herrenschmidt 868ac0385d9SChristopher Bostic 869ac0385d9SChristopher Bostic 870ac0385d9SChristopher Bostic static int fsi_master_gpio_remove(struct platform_device *pdev) 871ac0385d9SChristopher Bostic { 872ac0385d9SChristopher Bostic struct fsi_master_gpio *master = platform_get_drvdata(pdev); 873ac0385d9SChristopher Bostic 8748ef9ccf8SBenjamin Herrenschmidt device_remove_file(&pdev->dev, &dev_attr_external_mode); 875ac0385d9SChristopher Bostic 8768ef9ccf8SBenjamin Herrenschmidt fsi_master_unregister(&master->master); 877f6a2f8ebSJeremy Kerr 878ac0385d9SChristopher Bostic return 0; 879ac0385d9SChristopher Bostic } 880ac0385d9SChristopher Bostic 881ac0385d9SChristopher Bostic static const struct of_device_id fsi_master_gpio_match[] = { 882ac0385d9SChristopher Bostic { .compatible = "fsi-master-gpio" }, 883ac0385d9SChristopher Bostic { }, 884ac0385d9SChristopher Bostic }; 885ac0385d9SChristopher Bostic 886ac0385d9SChristopher Bostic static struct platform_driver fsi_master_gpio_driver = { 887ac0385d9SChristopher Bostic .driver = { 888ac0385d9SChristopher Bostic .name = "fsi-master-gpio", 889ac0385d9SChristopher Bostic .of_match_table = fsi_master_gpio_match, 890ac0385d9SChristopher Bostic }, 891ac0385d9SChristopher Bostic .probe = fsi_master_gpio_probe, 892ac0385d9SChristopher Bostic .remove = fsi_master_gpio_remove, 893ac0385d9SChristopher Bostic }; 894ac0385d9SChristopher Bostic 895ac0385d9SChristopher Bostic module_platform_driver(fsi_master_gpio_driver); 896ac0385d9SChristopher Bostic MODULE_LICENSE("GPL"); 897