1 /* SPDX-License-Identifier: GPL-2.0-or-later */
3 /***************************************************************************
4 * Copyright (C) 2013 by Paul Fertser, fercerpav@gmail.com *
6 * Copyright (C) 2012 by Creative Product Design, marc @ cpdesign.com.au *
7 * Based on at91rm9200.c (c) Anders Larsen *
8 * and RPi GPIO examples by Gert van Loo & Dom *
9 ***************************************************************************/
15 #include <jtag/adapter.h>
16 #include <jtag/interface.h>
17 #include <transport/transport.h>
22 uint32_t bcm2835_peri_base = 0x20000000;
23 #define BCM2835_GPIO_BASE (bcm2835_peri_base + 0x200000) /* GPIO controller */
25 #define BCM2835_PADS_GPIO_0_27 (bcm2835_peri_base + 0x100000)
26 #define BCM2835_PADS_GPIO_0_27_OFFSET (0x2c / 4)
28 /* See "GPIO Function Select Registers (GPFSELn)" in "Broadcom BCM2835 ARM Peripherals" datasheet. */
29 #define BCM2835_GPIO_MODE_INPUT 0
30 #define BCM2835_GPIO_MODE_OUTPUT 1
32 /* GPIO setup macros */
33 #define MODE_GPIO(g) (*(pio_base+((g)/10))>>(((g)%10)*3) & 7)
34 #define INP_GPIO(g) do { *(pio_base+((g)/10)) &= ~(7<<(((g)%10)*3)); } while (0)
35 #define SET_MODE_GPIO(g, m) do { /* clear the mode bits first, then set as necessary */ \
37 *(pio_base+((g)/10)) |= ((m)<<(((g)%10)*3)); } while (0)
38 #define OUT_GPIO(g) SET_MODE_GPIO(g, BCM2835_GPIO_MODE_OUTPUT)
40 #define GPIO_SET (*(pio_base+7)) /* sets bits which are 1, ignores bits which are 0 */
41 #define GPIO_CLR (*(pio_base+10)) /* clears bits which are 1, ignores bits which are 0 */
42 #define GPIO_LEV (*(pio_base+13)) /* current level of the pin */
44 static int dev_mem_fd;
45 static volatile uint32_t *pio_base = MAP_FAILED;
46 static volatile uint32_t *pads_base = MAP_FAILED;
48 /* Transition delay coefficients */
49 static int speed_coeff = 113714;
50 static int speed_offset = 28;
51 static unsigned int jtag_delay;
53 static const struct adapter_gpio_config *adapter_gpio_config;
54 static int initial_gpio_mode[ADAPTER_GPIO_IDX_NUM];
56 static bool is_gpio_config_valid(enum adapter_gpio_config_index idx)
58 /* Only chip 0 is supported, accept unset value (-1) too */
59 return adapter_gpio_config[idx].chip_num >= -1
60 && adapter_gpio_config[idx].chip_num <= 0
61 && adapter_gpio_config[idx].gpio_num >= 0
62 && adapter_gpio_config[idx].gpio_num <= 31;
65 static void set_gpio_value(const struct adapter_gpio_config *gpio_config, int value)
67 value = value ^ (gpio_config->active_low ? 1 : 0);
68 switch (gpio_config->drive) {
69 case ADAPTER_GPIO_DRIVE_MODE_PUSH_PULL:
71 GPIO_SET = 1 << gpio_config->gpio_num;
73 GPIO_CLR = 1 << gpio_config->gpio_num;
74 /* For performance reasons assume the GPIO is already set as an output
75 * and therefore the call can be omitted here.
78 case ADAPTER_GPIO_DRIVE_MODE_OPEN_DRAIN:
80 INP_GPIO(gpio_config->gpio_num);
82 GPIO_CLR = 1 << gpio_config->gpio_num;
83 OUT_GPIO(gpio_config->gpio_num);
86 case ADAPTER_GPIO_DRIVE_MODE_OPEN_SOURCE:
88 GPIO_SET = 1 << gpio_config->gpio_num;
89 OUT_GPIO(gpio_config->gpio_num);
91 INP_GPIO(gpio_config->gpio_num);
97 static void restore_gpio(enum adapter_gpio_config_index idx)
99 if (is_gpio_config_valid(idx))
100 SET_MODE_GPIO(adapter_gpio_config[idx].gpio_num, initial_gpio_mode[idx]);
103 static void initialize_gpio(enum adapter_gpio_config_index idx)
105 if (!is_gpio_config_valid(idx))
108 initial_gpio_mode[idx] = MODE_GPIO(adapter_gpio_config[idx].gpio_num);
109 LOG_DEBUG("saved GPIO mode for %s (GPIO %d %d): %d",
110 adapter_gpio_get_name(idx), adapter_gpio_config[idx].chip_num, adapter_gpio_config[idx].gpio_num,
111 initial_gpio_mode[idx]);
113 if (adapter_gpio_config[idx].pull != ADAPTER_GPIO_PULL_NONE) {
114 LOG_WARNING("BCM2835 GPIO does not support pull-up or pull-down settings (signal %s)",
115 adapter_gpio_get_name(idx));
118 switch (adapter_gpio_config[idx].init_state) {
119 case ADAPTER_GPIO_INIT_STATE_INACTIVE:
120 set_gpio_value(&adapter_gpio_config[idx], 0);
122 case ADAPTER_GPIO_INIT_STATE_ACTIVE:
123 set_gpio_value(&adapter_gpio_config[idx], 1);
125 case ADAPTER_GPIO_INIT_STATE_INPUT:
126 INP_GPIO(adapter_gpio_config[idx].gpio_num);
130 /* Direction for non push-pull is already set by set_gpio_value() */
131 if (adapter_gpio_config[idx].drive == ADAPTER_GPIO_DRIVE_MODE_PUSH_PULL)
132 OUT_GPIO(adapter_gpio_config[idx].gpio_num);
135 static bb_value_t bcm2835gpio_read(void)
137 unsigned int shift = adapter_gpio_config[ADAPTER_GPIO_IDX_TDO].gpio_num;
138 uint32_t value = (GPIO_LEV >> shift) & 1;
139 return value ^ (adapter_gpio_config[ADAPTER_GPIO_IDX_TDO].active_low ? BB_HIGH : BB_LOW);
143 static int bcm2835gpio_write(int tck, int tms, int tdi)
145 uint32_t set = tck << adapter_gpio_config[ADAPTER_GPIO_IDX_TCK].gpio_num |
146 tms << adapter_gpio_config[ADAPTER_GPIO_IDX_TMS].gpio_num |
147 tdi << adapter_gpio_config[ADAPTER_GPIO_IDX_TDI].gpio_num;
148 uint32_t clear = !tck << adapter_gpio_config[ADAPTER_GPIO_IDX_TCK].gpio_num |
149 !tms << adapter_gpio_config[ADAPTER_GPIO_IDX_TMS].gpio_num |
150 !tdi << adapter_gpio_config[ADAPTER_GPIO_IDX_TDI].gpio_num;
155 for (unsigned int i = 0; i < jtag_delay; i++)
161 /* Requires push-pull drive mode for swclk and swdio */
162 static int bcm2835gpio_swd_write_fast(int swclk, int swdio)
164 swclk = swclk ^ (adapter_gpio_config[ADAPTER_GPIO_IDX_SWCLK].active_low ? 1 : 0);
165 swdio = swdio ^ (adapter_gpio_config[ADAPTER_GPIO_IDX_SWDIO].active_low ? 1 : 0);
167 uint32_t set = swclk << adapter_gpio_config[ADAPTER_GPIO_IDX_SWCLK].gpio_num |
168 swdio << adapter_gpio_config[ADAPTER_GPIO_IDX_SWDIO].gpio_num;
169 uint32_t clear = !swclk << adapter_gpio_config[ADAPTER_GPIO_IDX_SWCLK].gpio_num |
170 !swdio << adapter_gpio_config[ADAPTER_GPIO_IDX_SWDIO].gpio_num;
175 for (unsigned int i = 0; i < jtag_delay; i++)
181 /* Generic mode that works for open-drain/open-source drive modes, but slower */
182 static int bcm2835gpio_swd_write_generic(int swclk, int swdio)
184 set_gpio_value(&adapter_gpio_config[ADAPTER_GPIO_IDX_SWDIO], swdio);
185 set_gpio_value(&adapter_gpio_config[ADAPTER_GPIO_IDX_SWCLK], swclk); /* Write clock last */
187 for (unsigned int i = 0; i < jtag_delay; ++i)
193 /* (1) assert or (0) deassert reset lines */
194 static int bcm2835gpio_reset(int trst, int srst)
196 /* As the "adapter reset_config" command keeps the srst and trst gpio drive
197 * mode settings in sync we can use our standard set_gpio_value() function
198 * that honours drive mode and active low.
200 if (is_gpio_config_valid(ADAPTER_GPIO_IDX_SRST))
201 set_gpio_value(&adapter_gpio_config[ADAPTER_GPIO_IDX_SRST], srst);
203 if (is_gpio_config_valid(ADAPTER_GPIO_IDX_TRST))
204 set_gpio_value(&adapter_gpio_config[ADAPTER_GPIO_IDX_TRST], trst);
206 LOG_DEBUG("BCM2835 GPIO: bcm2835gpio_reset(%d, %d), trst_gpio: %d %d, srst_gpio: %d %d",
208 adapter_gpio_config[ADAPTER_GPIO_IDX_TRST].chip_num, adapter_gpio_config[ADAPTER_GPIO_IDX_TRST].gpio_num,
209 adapter_gpio_config[ADAPTER_GPIO_IDX_SRST].chip_num, adapter_gpio_config[ADAPTER_GPIO_IDX_SRST].gpio_num);
213 static void bcm2835_swdio_drive(bool is_output)
216 if (is_gpio_config_valid(ADAPTER_GPIO_IDX_SWDIO_DIR))
217 set_gpio_value(&adapter_gpio_config[ADAPTER_GPIO_IDX_SWDIO_DIR], 1);
218 OUT_GPIO(adapter_gpio_config[ADAPTER_GPIO_IDX_SWDIO].gpio_num);
220 INP_GPIO(adapter_gpio_config[ADAPTER_GPIO_IDX_SWDIO].gpio_num);
221 if (is_gpio_config_valid(ADAPTER_GPIO_IDX_SWDIO_DIR))
222 set_gpio_value(&adapter_gpio_config[ADAPTER_GPIO_IDX_SWDIO_DIR], 0);
226 static int bcm2835_swdio_read(void)
228 unsigned int shift = adapter_gpio_config[ADAPTER_GPIO_IDX_SWDIO].gpio_num;
229 uint32_t value = (GPIO_LEV >> shift) & 1;
230 return value ^ (adapter_gpio_config[ADAPTER_GPIO_IDX_SWDIO].active_low ? 1 : 0);
233 static int bcm2835gpio_khz(int khz, int *jtag_speed)
236 LOG_DEBUG("BCM2835 GPIO: RCLK not supported");
239 *jtag_speed = speed_coeff/khz - speed_offset;
245 static int bcm2835gpio_speed_div(int speed, int *khz)
247 *khz = speed_coeff/(speed + speed_offset);
251 static int bcm2835gpio_speed(int speed)
257 COMMAND_HANDLER(bcm2835gpio_handle_speed_coeffs)
260 COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], speed_coeff);
261 COMMAND_PARSE_NUMBER(int, CMD_ARGV[1], speed_offset);
264 command_print(CMD, "BCM2835 GPIO: speed_coeffs = %d, speed_offset = %d",
265 speed_coeff, speed_offset);
269 COMMAND_HANDLER(bcm2835gpio_handle_peripheral_base)
272 COMMAND_PARSE_NUMBER(u32, CMD_ARGV[0], bcm2835_peri_base);
274 command_print(CMD, "BCM2835 GPIO: peripheral_base = 0x%08x",
279 static const struct command_registration bcm2835gpio_subcommand_handlers[] = {
281 .name = "speed_coeffs",
282 .handler = &bcm2835gpio_handle_speed_coeffs,
283 .mode = COMMAND_CONFIG,
284 .help = "SPEED_COEFF and SPEED_OFFSET for delay calculations.",
285 .usage = "[SPEED_COEFF SPEED_OFFSET]",
288 .name = "peripheral_base",
289 .handler = &bcm2835gpio_handle_peripheral_base,
290 .mode = COMMAND_CONFIG,
291 .help = "peripheral base to access GPIOs (RPi1 0x20000000, RPi2 0x3F000000).",
295 COMMAND_REGISTRATION_DONE
298 static const struct command_registration bcm2835gpio_command_handlers[] = {
300 .name = "bcm2835gpio",
302 .help = "perform bcm2835gpio management",
303 .chain = bcm2835gpio_subcommand_handlers,
306 COMMAND_REGISTRATION_DONE
309 static bool bcm2835gpio_jtag_mode_possible(void)
311 if (!is_gpio_config_valid(ADAPTER_GPIO_IDX_TCK))
313 if (!is_gpio_config_valid(ADAPTER_GPIO_IDX_TMS))
315 if (!is_gpio_config_valid(ADAPTER_GPIO_IDX_TDI))
317 if (!is_gpio_config_valid(ADAPTER_GPIO_IDX_TDO))
322 static bool bcm2835gpio_swd_mode_possible(void)
324 if (!is_gpio_config_valid(ADAPTER_GPIO_IDX_SWCLK))
326 if (!is_gpio_config_valid(ADAPTER_GPIO_IDX_SWDIO))
331 static void bcm2835gpio_munmap(void)
333 if (pio_base != MAP_FAILED) {
334 munmap((void *)pio_base, sysconf(_SC_PAGE_SIZE));
335 pio_base = MAP_FAILED;
338 if (pads_base != MAP_FAILED) {
339 munmap((void *)pads_base, sysconf(_SC_PAGE_SIZE));
340 pads_base = MAP_FAILED;
344 static int bcm2835gpio_blink(int on)
346 if (is_gpio_config_valid(ADAPTER_GPIO_IDX_LED))
347 set_gpio_value(&adapter_gpio_config[ADAPTER_GPIO_IDX_LED], on);
352 static struct bitbang_interface bcm2835gpio_bitbang = {
353 .read = bcm2835gpio_read,
354 .write = bcm2835gpio_write,
355 .swdio_read = bcm2835_swdio_read,
356 .swdio_drive = bcm2835_swdio_drive,
357 .swd_write = bcm2835gpio_swd_write_generic,
358 .blink = bcm2835gpio_blink,
361 static int bcm2835gpio_init(void)
363 LOG_INFO("BCM2835 GPIO JTAG/SWD bitbang driver");
365 bitbang_interface = &bcm2835gpio_bitbang;
366 adapter_gpio_config = adapter_gpio_get_config();
368 if (transport_is_jtag() && !bcm2835gpio_jtag_mode_possible()) {
369 LOG_ERROR("Require tck, tms, tdi and tdo gpios for JTAG mode");
370 return ERROR_JTAG_INIT_FAILED;
373 if (transport_is_swd() && !bcm2835gpio_swd_mode_possible()) {
374 LOG_ERROR("Require swclk and swdio gpio for SWD mode");
375 return ERROR_JTAG_INIT_FAILED;
378 dev_mem_fd = open("/dev/gpiomem", O_RDWR | O_SYNC);
379 if (dev_mem_fd < 0) {
380 LOG_DEBUG("Cannot open /dev/gpiomem, fallback to /dev/mem");
381 dev_mem_fd = open("/dev/mem", O_RDWR | O_SYNC);
383 if (dev_mem_fd < 0) {
384 LOG_ERROR("open: %s", strerror(errno));
385 return ERROR_JTAG_INIT_FAILED;
388 pio_base = mmap(NULL, sysconf(_SC_PAGE_SIZE), PROT_READ | PROT_WRITE,
389 MAP_SHARED, dev_mem_fd, BCM2835_GPIO_BASE);
391 if (pio_base == MAP_FAILED) {
392 LOG_ERROR("mmap: %s", strerror(errno));
394 return ERROR_JTAG_INIT_FAILED;
397 pads_base = mmap(NULL, sysconf(_SC_PAGE_SIZE), PROT_READ | PROT_WRITE,
398 MAP_SHARED, dev_mem_fd, BCM2835_PADS_GPIO_0_27);
400 if (pads_base == MAP_FAILED) {
401 LOG_ERROR("mmap: %s", strerror(errno));
402 bcm2835gpio_munmap();
404 return ERROR_JTAG_INIT_FAILED;
409 /* set 4mA drive strength, slew rate limited, hysteresis on */
410 pads_base[BCM2835_PADS_GPIO_0_27_OFFSET] = 0x5a000008 + 1;
412 /* Configure JTAG/SWD signals. Default directions and initial states are handled
413 * by adapter.c and "adapter gpio" command.
415 if (transport_is_jtag()) {
416 initialize_gpio(ADAPTER_GPIO_IDX_TDO);
417 initialize_gpio(ADAPTER_GPIO_IDX_TDI);
418 initialize_gpio(ADAPTER_GPIO_IDX_TMS);
419 initialize_gpio(ADAPTER_GPIO_IDX_TCK);
420 initialize_gpio(ADAPTER_GPIO_IDX_TRST);
423 if (transport_is_swd()) {
424 /* swdio and its buffer should be initialized in the order that prevents
425 * two outputs from being connected together. This will occur if the
426 * swdio GPIO of the AM335x is configured as an output while its
427 * external buffer is configured to send the swdio signal from the
428 * target to the AM335x.
430 if (adapter_gpio_config[ADAPTER_GPIO_IDX_SWDIO].init_state == ADAPTER_GPIO_INIT_STATE_INPUT) {
431 initialize_gpio(ADAPTER_GPIO_IDX_SWDIO);
432 initialize_gpio(ADAPTER_GPIO_IDX_SWDIO_DIR);
434 initialize_gpio(ADAPTER_GPIO_IDX_SWDIO_DIR);
435 initialize_gpio(ADAPTER_GPIO_IDX_SWDIO);
438 initialize_gpio(ADAPTER_GPIO_IDX_SWCLK);
440 if (adapter_gpio_config[ADAPTER_GPIO_IDX_SWCLK].drive == ADAPTER_GPIO_DRIVE_MODE_PUSH_PULL &&
441 adapter_gpio_config[ADAPTER_GPIO_IDX_SWDIO].drive == ADAPTER_GPIO_DRIVE_MODE_PUSH_PULL) {
442 LOG_DEBUG("BCM2835 GPIO using fast mode for SWD write");
443 bcm2835gpio_bitbang.swd_write = bcm2835gpio_swd_write_fast;
445 LOG_DEBUG("BCM2835 GPIO using generic mode for SWD write");
446 bcm2835gpio_bitbang.swd_write = bcm2835gpio_swd_write_generic;
450 initialize_gpio(ADAPTER_GPIO_IDX_SRST);
451 initialize_gpio(ADAPTER_GPIO_IDX_LED);
456 static int bcm2835gpio_quit(void)
458 if (transport_is_jtag()) {
459 restore_gpio(ADAPTER_GPIO_IDX_TDO);
460 restore_gpio(ADAPTER_GPIO_IDX_TDI);
461 restore_gpio(ADAPTER_GPIO_IDX_TCK);
462 restore_gpio(ADAPTER_GPIO_IDX_TMS);
463 restore_gpio(ADAPTER_GPIO_IDX_TRST);
466 if (transport_is_swd()) {
467 /* Restore swdio/swdio_dir to their initial modes, even if that means
468 * connecting two outputs. Begin by making swdio an input so that the
469 * current and final states of swdio and swdio_dir do not have to be
470 * considered to calculate the safe restoration order.
472 INP_GPIO(adapter_gpio_config[ADAPTER_GPIO_IDX_SWDIO].gpio_num);
473 restore_gpio(ADAPTER_GPIO_IDX_SWDIO_DIR);
474 restore_gpio(ADAPTER_GPIO_IDX_SWDIO);
475 restore_gpio(ADAPTER_GPIO_IDX_SWCLK);
478 restore_gpio(ADAPTER_GPIO_IDX_SRST);
479 restore_gpio(ADAPTER_GPIO_IDX_LED);
481 bcm2835gpio_munmap();
487 static const char * const bcm2835_transports[] = { "jtag", "swd", NULL };
489 static struct jtag_interface bcm2835gpio_interface = {
490 .supported = DEBUG_CAP_TMS_SEQ,
491 .execute_queue = bitbang_execute_queue,
493 struct adapter_driver bcm2835gpio_adapter_driver = {
494 .name = "bcm2835gpio",
495 .transports = bcm2835_transports,
496 .commands = bcm2835gpio_command_handlers,
498 .init = bcm2835gpio_init,
499 .quit = bcm2835gpio_quit,
500 .reset = bcm2835gpio_reset,
501 .speed = bcm2835gpio_speed,
502 .khz = bcm2835gpio_khz,
503 .speed_div = bcm2835gpio_speed_div,
505 .jtag_ops = &bcm2835gpio_interface,
506 .swd_ops = &bitbang_swd,