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
clock_toggle(struct fsi_master_gpio * master,int count)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
sda_clock_in(struct fsi_master_gpio * master)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
sda_out(struct fsi_master_gpio * master,int value)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
set_sda_input(struct fsi_master_gpio * master)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
set_sda_output(struct fsi_master_gpio * master,int value)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
clock_zeros(struct fsi_master_gpio * master,int count)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
echo_delay(struct fsi_master_gpio * master)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
serial_in(struct fsi_master_gpio * master,struct fsi_gpio_msg * msg,uint8_t num_bits)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
serial_out(struct fsi_master_gpio * master,const struct fsi_gpio_msg * cmd)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
msg_push_bits(struct fsi_gpio_msg * msg,uint64_t data,int bits)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
msg_push_crc(struct fsi_gpio_msg * msg)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
check_same_address(struct fsi_master_gpio * master,int id,uint32_t addr)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
check_relative_address(struct fsi_master_gpio * master,int id,uint32_t addr,uint32_t * rel_addrp)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
last_address_update(struct fsi_master_gpio * master,int id,bool valid,uint32_t addr)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 */
build_ar_command(struct fsi_master_gpio * master,struct fsi_gpio_msg * cmd,uint8_t id,uint32_t addr,size_t size,const void * data)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
build_dpoll_command(struct fsi_gpio_msg * cmd,uint8_t slave_id)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
build_epoll_command(struct fsi_gpio_msg * cmd,uint8_t slave_id)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
build_term_command(struct fsi_gpio_msg * cmd,uint8_t slave_id)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 */
read_one_response(struct fsi_master_gpio * master,uint8_t data_size,struct fsi_gpio_msg * msgp,uint8_t * tagp)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
issue_term(struct fsi_master_gpio * master,uint8_t slave)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
poll_for_response(struct fsi_master_gpio * master,uint8_t slave,uint8_t size,void * data)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
send_request(struct fsi_master_gpio * master,struct fsi_gpio_msg * cmd)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
fsi_master_gpio_xfer(struct fsi_master_gpio * master,uint8_t slave,struct fsi_gpio_msg * cmd,size_t resp_len,void * resp)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
fsi_master_gpio_read(struct fsi_master * _master,int link,uint8_t id,uint32_t addr,void * val,size_t size)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
fsi_master_gpio_write(struct fsi_master * _master,int link,uint8_t id,uint32_t addr,const void * val,size_t size)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
fsi_master_gpio_term(struct fsi_master * _master,int link,uint8_t id)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
fsi_master_gpio_break(struct fsi_master * _master,int link)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
fsi_master_gpio_init(struct fsi_master_gpio * master)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
fsi_master_gpio_init_external(struct fsi_master_gpio * master)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
fsi_master_gpio_link_enable(struct fsi_master * _master,int link,bool enable)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
fsi_master_gpio_link_config(struct fsi_master * _master,int link,u8 t_send_delay,u8 t_echo_delay)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
external_mode_show(struct device * dev,struct device_attribute * attr,char * buf)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
external_mode_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)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
fsi_master_gpio_release(struct device * dev)7628ef9ccf8SBenjamin Herrenschmidt static void fsi_master_gpio_release(struct device *dev)
7638ef9ccf8SBenjamin Herrenschmidt {
764*d5d8dfb0SEddie James struct fsi_master_gpio *master = to_fsi_master_gpio(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
fsi_master_gpio_probe(struct platform_device * pdev)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
fsi_master_gpio_remove(struct platform_device * pdev)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 };
88519a52178SZou Wei MODULE_DEVICE_TABLE(of, fsi_master_gpio_match);
886ac0385d9SChristopher Bostic
887ac0385d9SChristopher Bostic static struct platform_driver fsi_master_gpio_driver = {
888ac0385d9SChristopher Bostic .driver = {
889ac0385d9SChristopher Bostic .name = "fsi-master-gpio",
890ac0385d9SChristopher Bostic .of_match_table = fsi_master_gpio_match,
891ac0385d9SChristopher Bostic },
892ac0385d9SChristopher Bostic .probe = fsi_master_gpio_probe,
893ac0385d9SChristopher Bostic .remove = fsi_master_gpio_remove,
894ac0385d9SChristopher Bostic };
895ac0385d9SChristopher Bostic
896ac0385d9SChristopher Bostic module_platform_driver(fsi_master_gpio_driver);
897ac0385d9SChristopher Bostic MODULE_LICENSE("GPL");
898