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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * dm355evm_msp.c - driver for MSP430 firmware on DM355EVM board
4 *
5 * Copyright (C) 2008 David Brownell
6 */
7
8#include <linux/init.h>
9#include <linux/mutex.h>
10#include <linux/platform_device.h>
11#include <linux/clk.h>
12#include <linux/module.h>
13#include <linux/err.h>
14#include <linux/gpio.h>
15#include <linux/leds.h>
16#include <linux/i2c.h>
17#include <linux/mfd/dm355evm_msp.h>
18
19
20/*
21 * The DM355 is a DaVinci chip with video support but no C64+ DSP. Its
22 * EVM board has an MSP430 programmed with firmware for various board
23 * support functions. This driver exposes some of them directly, and
24 * supports other drivers (e.g. RTC, input) for more complex access.
25 *
26 * Because this firmware is entirely board-specific, this file embeds
27 * knowledge that would be passed as platform_data in a generic driver.
28 *
29 * This driver was tested with firmware revision A4.
30 */
31
32#if IS_ENABLED(CONFIG_INPUT_DM355EVM)
33#define msp_has_keyboard() true
34#else
35#define msp_has_keyboard() false
36#endif
37
38#if IS_ENABLED(CONFIG_LEDS_GPIO)
39#define msp_has_leds() true
40#else
41#define msp_has_leds() false
42#endif
43
44#if IS_ENABLED(CONFIG_RTC_DRV_DM355EVM)
45#define msp_has_rtc() true
46#else
47#define msp_has_rtc() false
48#endif
49
50#if IS_ENABLED(CONFIG_VIDEO_TVP514X)
51#define msp_has_tvp() true
52#else
53#define msp_has_tvp() false
54#endif
55
56
57/*----------------------------------------------------------------------*/
58
59/* REVISIT for paranoia's sake, retry reads/writes on error */
60
61static struct i2c_client *msp430;
62
63/**
64 * dm355evm_msp_write - Writes a register in dm355evm_msp
65 * @value: the value to be written
66 * @reg: register address
67 *
68 * Returns result of operation - 0 is success, else negative errno
69 */
70int dm355evm_msp_write(u8 value, u8 reg)
71{
72 return i2c_smbus_write_byte_data(msp430, reg, value);
73}
74EXPORT_SYMBOL(dm355evm_msp_write);
75
76/**
77 * dm355evm_msp_read - Reads a register from dm355evm_msp
78 * @reg: register address
79 *
80 * Returns result of operation - value, or negative errno
81 */
82int dm355evm_msp_read(u8 reg)
83{
84 return i2c_smbus_read_byte_data(msp430, reg);
85}
86EXPORT_SYMBOL(dm355evm_msp_read);
87
88/*----------------------------------------------------------------------*/
89
90/*
91 * Many of the msp430 pins are just used as fixed-direction GPIOs.
92 * We could export a few more of them this way, if we wanted.
93 */
94#define MSP_GPIO(bit, reg) ((DM355EVM_MSP_ ## reg) << 3 | (bit))
95
96static const u8 msp_gpios[] = {
97 /* eight leds */
98 MSP_GPIO(0, LED), MSP_GPIO(1, LED),
99 MSP_GPIO(2, LED), MSP_GPIO(3, LED),
100 MSP_GPIO(4, LED), MSP_GPIO(5, LED),
101 MSP_GPIO(6, LED), MSP_GPIO(7, LED),
102 /* SW6 and the NTSC/nPAL jumper */
103 MSP_GPIO(0, SWITCH1), MSP_GPIO(1, SWITCH1),
104 MSP_GPIO(2, SWITCH1), MSP_GPIO(3, SWITCH1),
105 MSP_GPIO(4, SWITCH1),
106 /* switches on MMC/SD sockets */
107 /*
108 * Note: EVMDM355_ECP_VA4.pdf suggests that Bit 2 and 4 should be
109 * checked for card detection. However on the EVM bit 1 and 3 gives
110 * this status, for 0 and 1 instance respectively. The pdf also
111 * suggests that Bit 1 and 3 should be checked for write protection.
112 * However on the EVM bit 2 and 4 gives this status,for 0 and 1
113 * instance respectively.
114 */
115 MSP_GPIO(2, SDMMC), MSP_GPIO(1, SDMMC), /* mmc0 WP, nCD */
116 MSP_GPIO(4, SDMMC), MSP_GPIO(3, SDMMC), /* mmc1 WP, nCD */
117};
118
119#define MSP_GPIO_REG(offset) (msp_gpios[(offset)] >> 3)
120#define MSP_GPIO_MASK(offset) BIT(msp_gpios[(offset)] & 0x07)
121
122static int msp_gpio_in(struct gpio_chip *chip, unsigned offset)
123{
124 switch (MSP_GPIO_REG(offset)) {
125 case DM355EVM_MSP_SWITCH1:
126 case DM355EVM_MSP_SWITCH2:
127 case DM355EVM_MSP_SDMMC:
128 return 0;
129 default:
130 return -EINVAL;
131 }
132}
133
134static u8 msp_led_cache;
135
136static int msp_gpio_get(struct gpio_chip *chip, unsigned offset)
137{
138 int reg, status;
139
140 reg = MSP_GPIO_REG(offset);
141 status = dm355evm_msp_read(reg);
142 if (status < 0)
143 return status;
144 if (reg == DM355EVM_MSP_LED)
145 msp_led_cache = status;
146 return !!(status & MSP_GPIO_MASK(offset));
147}
148
149static int msp_gpio_out(struct gpio_chip *chip, unsigned offset, int value)
150{
151 int mask, bits;
152
153 /* NOTE: there are some other signals that could be
154 * packaged as output GPIOs, but they aren't as useful
155 * as the LEDs ... so for now we don't.
156 */
157 if (MSP_GPIO_REG(offset) != DM355EVM_MSP_LED)
158 return -EINVAL;
159
160 mask = MSP_GPIO_MASK(offset);
161 bits = msp_led_cache;
162
163 bits &= ~mask;
164 if (value)
165 bits |= mask;
166 msp_led_cache = bits;
167
168 return dm355evm_msp_write(bits, DM355EVM_MSP_LED);
169}
170
171static void msp_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
172{
173 msp_gpio_out(chip, offset, value);
174}
175
176static struct gpio_chip dm355evm_msp_gpio = {
177 .label = "dm355evm_msp",
178 .owner = THIS_MODULE,
179 .direction_input = msp_gpio_in,
180 .get = msp_gpio_get,
181 .direction_output = msp_gpio_out,
182 .set = msp_gpio_set,
183 .base = -EINVAL, /* dynamic assignment */
184 .ngpio = ARRAY_SIZE(msp_gpios),
185 .can_sleep = true,
186};
187
188/*----------------------------------------------------------------------*/
189
190static struct device *add_child(struct i2c_client *client, const char *name,
191 void *pdata, unsigned pdata_len,
192 bool can_wakeup, int irq)
193{
194 struct platform_device *pdev;
195 int status;
196
197 pdev = platform_device_alloc(name, -1);
198 if (!pdev)
199 return ERR_PTR(-ENOMEM);
200
201 device_init_wakeup(&pdev->dev, can_wakeup);
202 pdev->dev.parent = &client->dev;
203
204 if (pdata) {
205 status = platform_device_add_data(pdev, pdata, pdata_len);
206 if (status < 0) {
207 dev_dbg(&pdev->dev, "can't add platform_data\n");
208 goto put_device;
209 }
210 }
211
212 if (irq) {
213 struct resource r = {
214 .start = irq,
215 .flags = IORESOURCE_IRQ,
216 };
217
218 status = platform_device_add_resources(pdev, &r, 1);
219 if (status < 0) {
220 dev_dbg(&pdev->dev, "can't add irq\n");
221 goto put_device;
222 }
223 }
224
225 status = platform_device_add(pdev);
226 if (status)
227 goto put_device;
228
229 return &pdev->dev;
230
231put_device:
232 platform_device_put(pdev);
233 dev_err(&client->dev, "failed to add device %s\n", name);
234 return ERR_PTR(status);
235}
236
237static int add_children(struct i2c_client *client)
238{
239 static const struct {
240 int offset;
241 char *label;
242 } config_inputs[] = {
243 /* 8 == right after the LEDs */
244 { 8 + 0, "sw6_1", },
245 { 8 + 1, "sw6_2", },
246 { 8 + 2, "sw6_3", },
247 { 8 + 3, "sw6_4", },
248 { 8 + 4, "NTSC/nPAL", },
249 };
250
251 struct device *child;
252 int status;
253 int i;
254
255 /* GPIO-ish stuff */
256 dm355evm_msp_gpio.parent = &client->dev;
257 status = gpiochip_add_data(&dm355evm_msp_gpio, NULL);
258 if (status < 0)
259 return status;
260
261 /* LED output */
262 if (msp_has_leds()) {
263#define GPIO_LED(l) .name = l, .active_low = true
264 static struct gpio_led evm_leds[] = {
265 { GPIO_LED("dm355evm::ds14"),
266 .default_trigger = "heartbeat", },
267 { GPIO_LED("dm355evm::ds15"),
268 .default_trigger = "mmc0", },
269 { GPIO_LED("dm355evm::ds16"),
270 /* could also be a CE-ATA drive */
271 .default_trigger = "mmc1", },
272 { GPIO_LED("dm355evm::ds17"),
273 .default_trigger = "nand-disk", },
274 { GPIO_LED("dm355evm::ds18"), },
275 { GPIO_LED("dm355evm::ds19"), },
276 { GPIO_LED("dm355evm::ds20"), },
277 { GPIO_LED("dm355evm::ds21"), },
278 };
279#undef GPIO_LED
280
281 struct gpio_led_platform_data evm_led_data = {
282 .num_leds = ARRAY_SIZE(evm_leds),
283 .leds = evm_leds,
284 };
285
286 for (i = 0; i < ARRAY_SIZE(evm_leds); i++)
287 evm_leds[i].gpio = i + dm355evm_msp_gpio.base;
288
289 /* NOTE: these are the only fully programmable LEDs
290 * on the board, since GPIO-61/ds22 (and many signals
291 * going to DC7) must be used for AEMIF address lines
292 * unless the top 1 GB of NAND is unused...
293 */
294 child = add_child(client, "leds-gpio",
295 &evm_led_data, sizeof(evm_led_data),
296 false, 0);
297 if (IS_ERR(child))
298 return PTR_ERR(child);
299 }
300
301 /* configuration inputs */
302 for (i = 0; i < ARRAY_SIZE(config_inputs); i++) {
303 int gpio = dm355evm_msp_gpio.base + config_inputs[i].offset;
304
305 gpio_request_one(gpio, GPIOF_IN, config_inputs[i].label);
306
307 /* make it easy for userspace to see these */
308 gpio_export(gpio, false);
309 }
310
311 /* MMC/SD inputs -- right after the last config input */
312 if (dev_get_platdata(&client->dev)) {
313 void (*mmcsd_setup)(unsigned) = dev_get_platdata(&client->dev);
314
315 mmcsd_setup(dm355evm_msp_gpio.base + 8 + 5);
316 }
317
318 /* RTC is a 32 bit counter, no alarm */
319 if (msp_has_rtc()) {
320 child = add_child(client, "rtc-dm355evm",
321 NULL, 0, false, 0);
322 if (IS_ERR(child))
323 return PTR_ERR(child);
324 }
325
326 /* input from buttons and IR remote (uses the IRQ) */
327 if (msp_has_keyboard()) {
328 child = add_child(client, "dm355evm_keys",
329 NULL, 0, true, client->irq);
330 if (IS_ERR(child))
331 return PTR_ERR(child);
332 }
333
334 return 0;
335}
336
337/*----------------------------------------------------------------------*/
338
339static void dm355evm_command(unsigned command)
340{
341 int status;
342
343 status = dm355evm_msp_write(command, DM355EVM_MSP_COMMAND);
344 if (status < 0)
345 dev_err(&msp430->dev, "command %d failure %d\n",
346 command, status);
347}
348
349static void dm355evm_power_off(void)
350{
351 dm355evm_command(MSP_COMMAND_POWEROFF);
352}
353
354static int dm355evm_msp_remove(struct i2c_client *client)
355{
356 pm_power_off = NULL;
357 msp430 = NULL;
358 return 0;
359}
360
361static int
362dm355evm_msp_probe(struct i2c_client *client, const struct i2c_device_id *id)
363{
364 int status;
365 const char *video = msp_has_tvp() ? "TVP5146" : "imager";
366
367 if (msp430)
368 return -EBUSY;
369 msp430 = client;
370
371 /* display revision status; doubles as sanity check */
372 status = dm355evm_msp_read(DM355EVM_MSP_FIRMREV);
373 if (status < 0)
374 goto fail;
375 dev_info(&client->dev, "firmware v.%02X, %s as video-in\n",
376 status, video);
377
378 /* mux video input: either tvp5146 or some external imager */
379 status = dm355evm_msp_write(msp_has_tvp() ? 0 : MSP_VIDEO_IMAGER,
380 DM355EVM_MSP_VIDEO_IN);
381 if (status < 0)
382 dev_warn(&client->dev, "error %d muxing %s as video-in\n",
383 status, video);
384
385 /* init LED cache, and turn off the LEDs */
386 msp_led_cache = 0xff;
387 dm355evm_msp_write(msp_led_cache, DM355EVM_MSP_LED);
388
389 /* export capabilities we support */
390 status = add_children(client);
391 if (status < 0)
392 goto fail;
393
394 /* PM hookup */
395 pm_power_off = dm355evm_power_off;
396
397 return 0;
398
399fail:
400 /* FIXME remove children ... */
401 dm355evm_msp_remove(client);
402 return status;
403}
404
405static const struct i2c_device_id dm355evm_msp_ids[] = {
406 { "dm355evm_msp", 0 },
407 { /* end of list */ },
408};
409MODULE_DEVICE_TABLE(i2c, dm355evm_msp_ids);
410
411static struct i2c_driver dm355evm_msp_driver = {
412 .driver.name = "dm355evm_msp",
413 .id_table = dm355evm_msp_ids,
414 .probe = dm355evm_msp_probe,
415 .remove = dm355evm_msp_remove,
416};
417
418static int __init dm355evm_msp_init(void)
419{
420 return i2c_add_driver(&dm355evm_msp_driver);
421}
422subsys_initcall(dm355evm_msp_init);
423
424static void __exit dm355evm_msp_exit(void)
425{
426 i2c_del_driver(&dm355evm_msp_driver);
427}
428module_exit(dm355evm_msp_exit);
429
430MODULE_DESCRIPTION("Interface to MSP430 firmware on DM355EVM");
431MODULE_LICENSE("GPL");