2 * SPI driver for the CPLD chip on the Mikrotik RB4xx boards
4 * Copyright (C) 2010 Gabor Juhos <juhosg@openwrt.org>
6 * This file was based on the patches for Linux 2.6.27.39 published by
7 * MikroTik for their RouterBoard 4xx series devices.
9 * This program is free software; you can redistribute it and/or modify it
10 * under the terms of the GNU General Public License version 2 as published
11 * by the Free Software Foundation.
14 #include <linux/types.h>
15 #include <linux/kernel.h>
16 #include <linux/module.h>
17 #include <linux/init.h>
18 #include <linux/module.h>
19 #include <linux/device.h>
20 #include <linux/bitops.h>
21 #include <linux/spi/spi.h>
22 #include <linux/gpio.h>
23 #include <linux/slab.h>
24 #include <linux/version.h>
26 #include <asm/mach-ath79/rb4xx_cpld.h>
28 #define DRV_NAME "spi-rb4xx-cpld"
29 #define DRV_DESC "RB4xx CPLD driver"
30 #define DRV_VERSION "0.1.0"
32 #define CPLD_CMD_WRITE_NAND 0x08 /* send cmd, n x send data, send indle */
33 #define CPLD_CMD_WRITE_CFG 0x09 /* send cmd, n x send cfg */
34 #define CPLD_CMD_READ_NAND 0x0a /* send cmd, send idle, n x read data */
35 #define CPLD_CMD_READ_FAST 0x0b /* send cmd, 4 x idle, n x read data */
36 #define CPLD_CMD_LED5_ON 0x0c /* send cmd */
37 #define CPLD_CMD_LED5_OFF 0x0d /* send cmd */
40 struct spi_device *spi;
42 struct gpio_chip chip;
46 static struct rb4xx_cpld *rb4xx_cpld;
48 static inline struct rb4xx_cpld *gpio_to_cpld(struct gpio_chip *chip)
50 return container_of(chip, struct rb4xx_cpld, chip);
53 static int rb4xx_cpld_write_cmd(struct rb4xx_cpld *cpld, unsigned char cmd)
55 struct spi_transfer t[1];
57 unsigned char tx_buf[1];
61 memset(&t, 0, sizeof(t));
64 t[0].len = sizeof(tx_buf);
65 spi_message_add_tail(&t[0], &m);
69 err = spi_sync(cpld->spi, &m);
73 static int rb4xx_cpld_write_cfg(struct rb4xx_cpld *cpld, unsigned char config)
75 struct spi_transfer t[1];
81 memset(&t, 0, sizeof(t));
84 t[0].len = sizeof(cmd);
85 spi_message_add_tail(&t[0], &m);
87 cmd[0] = CPLD_CMD_WRITE_CFG;
90 err = spi_sync(cpld->spi, &m);
94 static int __rb4xx_cpld_change_cfg(struct rb4xx_cpld *cpld, unsigned mask,
100 config = cpld->config & ~mask;
103 if ((cpld->config ^ config) & 0xff) {
104 err = rb4xx_cpld_write_cfg(cpld, config);
109 if ((cpld->config ^ config) & CPLD_CFG_nLED5) {
110 err = rb4xx_cpld_write_cmd(cpld, (value) ? CPLD_CMD_LED5_ON :
116 cpld->config = config;
120 int rb4xx_cpld_change_cfg(unsigned mask, unsigned value)
124 if (rb4xx_cpld == NULL)
127 mutex_lock(&rb4xx_cpld->lock);
128 ret = __rb4xx_cpld_change_cfg(rb4xx_cpld, mask, value);
129 mutex_unlock(&rb4xx_cpld->lock);
133 EXPORT_SYMBOL_GPL(rb4xx_cpld_change_cfg);
135 int rb4xx_cpld_read(unsigned char *rx_buf, unsigned count)
137 static const unsigned char cmd[2] = { CPLD_CMD_READ_NAND, 0 };
138 struct spi_transfer t[2] = {
147 struct spi_message m;
149 if (rb4xx_cpld == NULL)
152 spi_message_init(&m);
153 spi_message_add_tail(&t[0], &m);
154 spi_message_add_tail(&t[1], &m);
155 return spi_sync(rb4xx_cpld->spi, &m);
157 EXPORT_SYMBOL_GPL(rb4xx_cpld_read);
159 int rb4xx_cpld_write(const unsigned char *buf, unsigned count)
161 static const unsigned char cmd = CPLD_CMD_WRITE_NAND;
162 struct spi_transfer t[3] = {
169 .tx_nbits = SPI_NBITS_DUAL,
172 .tx_nbits = SPI_NBITS_DUAL,
175 struct spi_message m;
177 if (rb4xx_cpld == NULL)
180 spi_message_init(&m);
181 spi_message_add_tail(&t[0], &m);
182 spi_message_add_tail(&t[1], &m);
183 spi_message_add_tail(&t[2], &m);
184 return spi_sync(rb4xx_cpld->spi, &m);
186 EXPORT_SYMBOL_GPL(rb4xx_cpld_write);
188 static int rb4xx_cpld_gpio_get(struct gpio_chip *chip, unsigned offset)
190 struct rb4xx_cpld *cpld = gpio_to_cpld(chip);
193 mutex_lock(&cpld->lock);
194 ret = (cpld->config >> offset) & 1;
195 mutex_unlock(&cpld->lock);
200 static void rb4xx_cpld_gpio_set(struct gpio_chip *chip, unsigned offset,
203 struct rb4xx_cpld *cpld = gpio_to_cpld(chip);
205 mutex_lock(&cpld->lock);
206 __rb4xx_cpld_change_cfg(cpld, (1 << offset), !!value << offset);
207 mutex_unlock(&cpld->lock);
210 static int rb4xx_cpld_gpio_direction_input(struct gpio_chip *chip,
216 static int rb4xx_cpld_gpio_direction_output(struct gpio_chip *chip,
220 struct rb4xx_cpld *cpld = gpio_to_cpld(chip);
223 mutex_lock(&cpld->lock);
224 ret = __rb4xx_cpld_change_cfg(cpld, (1 << offset), !!value << offset);
225 mutex_unlock(&cpld->lock);
230 static int rb4xx_cpld_gpio_init(struct rb4xx_cpld *cpld, unsigned int base)
235 cpld->config = CPLD_CFG_nLED1 | CPLD_CFG_nLED2 | CPLD_CFG_nLED3 |
236 CPLD_CFG_nLED4 | CPLD_CFG_nCE;
237 rb4xx_cpld_write_cfg(cpld, cpld->config);
239 /* setup GPIO chip */
240 cpld->chip.label = DRV_NAME;
242 cpld->chip.get = rb4xx_cpld_gpio_get;
243 cpld->chip.set = rb4xx_cpld_gpio_set;
244 cpld->chip.direction_input = rb4xx_cpld_gpio_direction_input;
245 cpld->chip.direction_output = rb4xx_cpld_gpio_direction_output;
247 cpld->chip.base = base;
248 cpld->chip.ngpio = CPLD_NUM_GPIOS;
249 cpld->chip.can_sleep = 1;
250 #if LINUX_VERSION_CODE < KERNEL_VERSION(4,5,0)
251 cpld->chip.dev = &cpld->spi->dev;
253 cpld->chip.parent = &cpld->spi->dev;
255 cpld->chip.owner = THIS_MODULE;
257 err = gpiochip_add(&cpld->chip);
259 dev_err(&cpld->spi->dev, "adding GPIO chip failed, err=%d\n",
265 static int rb4xx_cpld_probe(struct spi_device *spi)
267 struct rb4xx_cpld *cpld;
268 struct rb4xx_cpld_platform_data *pdata;
271 pdata = spi->dev.platform_data;
273 dev_dbg(&spi->dev, "no platform data\n");
277 cpld = kzalloc(sizeof(*cpld), GFP_KERNEL);
279 dev_err(&spi->dev, "no memory for private data\n");
283 mutex_init(&cpld->lock);
284 cpld->spi = spi_dev_get(spi);
285 dev_set_drvdata(&spi->dev, cpld);
287 spi->mode = SPI_MODE_0 | SPI_TX_DUAL;
288 spi->bits_per_word = 8;
289 err = spi_setup(spi);
291 dev_err(&spi->dev, "spi_setup failed, err=%d\n", err);
295 err = rb4xx_cpld_gpio_init(cpld, pdata->gpio_base);
304 dev_set_drvdata(&spi->dev, NULL);
310 static int rb4xx_cpld_remove(struct spi_device *spi)
312 struct rb4xx_cpld *cpld;
315 cpld = dev_get_drvdata(&spi->dev);
316 dev_set_drvdata(&spi->dev, NULL);
322 static struct spi_driver rb4xx_cpld_driver = {
325 .bus = &spi_bus_type,
326 .owner = THIS_MODULE,
328 .probe = rb4xx_cpld_probe,
329 .remove = rb4xx_cpld_remove,
332 static int __init rb4xx_cpld_init(void)
334 return spi_register_driver(&rb4xx_cpld_driver);
336 module_init(rb4xx_cpld_init);
338 static void __exit rb4xx_cpld_exit(void)
340 spi_unregister_driver(&rb4xx_cpld_driver);
342 module_exit(rb4xx_cpld_exit);
344 MODULE_DESCRIPTION(DRV_DESC);
345 MODULE_VERSION(DRV_VERSION);
346 MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
347 MODULE_LICENSE("GPL v2");