diff options
Diffstat (limited to 'drivers/gpio')
-rw-r--r-- | drivers/gpio/Kconfig | 13 | ||||
-rw-r--r-- | drivers/gpio/Makefile | 2 | ||||
-rw-r--r-- | drivers/gpio/max7300.c | 94 | ||||
-rw-r--r-- | drivers/gpio/max7301.c | 293 | ||||
-rw-r--r-- | drivers/gpio/max730x.c | 244 |
5 files changed, 386 insertions, 260 deletions
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig index 1f1d88ae68d6..f3549b8779d8 100644 --- a/drivers/gpio/Kconfig +++ b/drivers/gpio/Kconfig | |||
@@ -65,6 +65,9 @@ config GPIO_SYSFS | |||
65 | 65 | ||
66 | # put expanders in the right section, in alphabetical order | 66 | # put expanders in the right section, in alphabetical order |
67 | 67 | ||
68 | config GPIO_MAX730X | ||
69 | tristate | ||
70 | |||
68 | comment "Memory mapped GPIO expanders:" | 71 | comment "Memory mapped GPIO expanders:" |
69 | 72 | ||
70 | config GPIO_PL061 | 73 | config GPIO_PL061 |
@@ -87,6 +90,13 @@ config GPIO_VR41XX | |||
87 | 90 | ||
88 | comment "I2C GPIO expanders:" | 91 | comment "I2C GPIO expanders:" |
89 | 92 | ||
93 | config GPIO_MAX7300 | ||
94 | tristate "Maxim MAX7300 GPIO expander" | ||
95 | depends on I2C | ||
96 | select GPIO_MAX730X | ||
97 | help | ||
98 | GPIO driver for Maxim MAX7301 I2C-based GPIO expander. | ||
99 | |||
90 | config GPIO_MAX732X | 100 | config GPIO_MAX732X |
91 | tristate "MAX7319, MAX7320-7327 I2C Port Expanders" | 101 | tristate "MAX7319, MAX7320-7327 I2C Port Expanders" |
92 | depends on I2C | 102 | depends on I2C |
@@ -226,8 +236,9 @@ comment "SPI GPIO expanders:" | |||
226 | config GPIO_MAX7301 | 236 | config GPIO_MAX7301 |
227 | tristate "Maxim MAX7301 GPIO expander" | 237 | tristate "Maxim MAX7301 GPIO expander" |
228 | depends on SPI_MASTER | 238 | depends on SPI_MASTER |
239 | select GPIO_MAX730X | ||
229 | help | 240 | help |
230 | gpio driver for Maxim MAX7301 SPI GPIO expander. | 241 | GPIO driver for Maxim MAX7301 SPI-based GPIO expander. |
231 | 242 | ||
232 | config GPIO_MCP23S08 | 243 | config GPIO_MCP23S08 |
233 | tristate "Microchip MCP23S08 I/O expander" | 244 | tristate "Microchip MCP23S08 I/O expander" |
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile index 48687238edb1..508a1b202cdb 100644 --- a/drivers/gpio/Makefile +++ b/drivers/gpio/Makefile | |||
@@ -7,6 +7,8 @@ obj-$(CONFIG_GPIOLIB) += gpiolib.o | |||
7 | obj-$(CONFIG_GPIO_ADP5520) += adp5520-gpio.o | 7 | obj-$(CONFIG_GPIO_ADP5520) += adp5520-gpio.o |
8 | obj-$(CONFIG_GPIO_ADP5588) += adp5588-gpio.o | 8 | obj-$(CONFIG_GPIO_ADP5588) += adp5588-gpio.o |
9 | obj-$(CONFIG_GPIO_LANGWELL) += langwell_gpio.o | 9 | obj-$(CONFIG_GPIO_LANGWELL) += langwell_gpio.o |
10 | obj-$(CONFIG_GPIO_MAX730X) += max730x.o | ||
11 | obj-$(CONFIG_GPIO_MAX7300) += max7300.o | ||
10 | obj-$(CONFIG_GPIO_MAX7301) += max7301.o | 12 | obj-$(CONFIG_GPIO_MAX7301) += max7301.o |
11 | obj-$(CONFIG_GPIO_MAX732X) += max732x.o | 13 | obj-$(CONFIG_GPIO_MAX732X) += max732x.o |
12 | obj-$(CONFIG_GPIO_MC33880) += mc33880.o | 14 | obj-$(CONFIG_GPIO_MC33880) += mc33880.o |
diff --git a/drivers/gpio/max7300.c b/drivers/gpio/max7300.c new file mode 100644 index 000000000000..9d74eef1157a --- /dev/null +++ b/drivers/gpio/max7300.c | |||
@@ -0,0 +1,94 @@ | |||
1 | /* | ||
2 | * drivers/gpio/max7300.c | ||
3 | * | ||
4 | * Copyright (C) 2009 Wolfram Sang, Pengutronix | ||
5 | * | ||
6 | * This program is free software; you can redistribute it and/or modify | ||
7 | * it under the terms of the GNU General Public License version 2 as | ||
8 | * published by the Free Software Foundation. | ||
9 | * | ||
10 | * Check max730x.c for further details. | ||
11 | */ | ||
12 | |||
13 | #include <linux/module.h> | ||
14 | #include <linux/init.h> | ||
15 | #include <linux/platform_device.h> | ||
16 | #include <linux/mutex.h> | ||
17 | #include <linux/i2c.h> | ||
18 | #include <linux/spi/max7301.h> | ||
19 | |||
20 | static int max7300_i2c_write(struct device *dev, unsigned int reg, | ||
21 | unsigned int val) | ||
22 | { | ||
23 | struct i2c_client *client = to_i2c_client(dev); | ||
24 | |||
25 | return i2c_smbus_write_byte_data(client, reg, val); | ||
26 | } | ||
27 | |||
28 | static int max7300_i2c_read(struct device *dev, unsigned int reg) | ||
29 | { | ||
30 | struct i2c_client *client = to_i2c_client(dev); | ||
31 | |||
32 | return i2c_smbus_read_byte_data(client, reg); | ||
33 | } | ||
34 | |||
35 | static int __devinit max7300_probe(struct i2c_client *client, | ||
36 | const struct i2c_device_id *id) | ||
37 | { | ||
38 | struct max7301 *ts; | ||
39 | int ret; | ||
40 | |||
41 | if (!i2c_check_functionality(client->adapter, | ||
42 | I2C_FUNC_SMBUS_BYTE_DATA)) | ||
43 | return -EIO; | ||
44 | |||
45 | ts = kzalloc(sizeof(struct max7301), GFP_KERNEL); | ||
46 | if (!ts) | ||
47 | return -ENOMEM; | ||
48 | |||
49 | ts->read = max7300_i2c_read; | ||
50 | ts->write = max7300_i2c_write; | ||
51 | ts->dev = &client->dev; | ||
52 | |||
53 | ret = __max730x_probe(ts); | ||
54 | if (ret) | ||
55 | kfree(ts); | ||
56 | return ret; | ||
57 | } | ||
58 | |||
59 | static int __devexit max7300_remove(struct i2c_client *client) | ||
60 | { | ||
61 | return __max730x_remove(&client->dev); | ||
62 | } | ||
63 | |||
64 | static const struct i2c_device_id max7300_id[] = { | ||
65 | { "max7300", 0 }, | ||
66 | { } | ||
67 | }; | ||
68 | MODULE_DEVICE_TABLE(i2c, max7300_id); | ||
69 | |||
70 | static struct i2c_driver max7300_driver = { | ||
71 | .driver = { | ||
72 | .name = "max7300", | ||
73 | .owner = THIS_MODULE, | ||
74 | }, | ||
75 | .probe = max7300_probe, | ||
76 | .remove = __devexit_p(max7300_remove), | ||
77 | .id_table = max7300_id, | ||
78 | }; | ||
79 | |||
80 | static int __init max7300_init(void) | ||
81 | { | ||
82 | return i2c_add_driver(&max7300_driver); | ||
83 | } | ||
84 | subsys_initcall(max7300_init); | ||
85 | |||
86 | static void __exit max7300_exit(void) | ||
87 | { | ||
88 | i2c_del_driver(&max7300_driver); | ||
89 | } | ||
90 | module_exit(max7300_exit); | ||
91 | |||
92 | MODULE_AUTHOR("Wolfram Sang"); | ||
93 | MODULE_LICENSE("GPL v2"); | ||
94 | MODULE_DESCRIPTION("MAX7300 GPIO-Expander"); | ||
diff --git a/drivers/gpio/max7301.c b/drivers/gpio/max7301.c index 480956f1ca50..965d9b1ea13e 100644 --- a/drivers/gpio/max7301.c +++ b/drivers/gpio/max7301.c | |||
@@ -1,98 +1,41 @@ | |||
1 | /** | 1 | /* |
2 | * drivers/gpio/max7301.c | 2 | * drivers/gpio/max7301.c |
3 | * | 3 | * |
4 | * Copyright (C) 2006 Juergen Beisert, Pengutronix | 4 | * Copyright (C) 2006 Juergen Beisert, Pengutronix |
5 | * Copyright (C) 2008 Guennadi Liakhovetski, Pengutronix | 5 | * Copyright (C) 2008 Guennadi Liakhovetski, Pengutronix |
6 | * Copyright (C) 2009 Wolfram Sang, Pengutronix | ||
6 | * | 7 | * |
7 | * This program is free software; you can redistribute it and/or modify | 8 | * This program is free software; you can redistribute it and/or modify |
8 | * it under the terms of the GNU General Public License version 2 as | 9 | * it under the terms of the GNU General Public License version 2 as |
9 | * published by the Free Software Foundation. | 10 | * published by the Free Software Foundation. |
10 | * | 11 | * |
11 | * The Maxim's MAX7301 device is an SPI driven GPIO expander. There are | 12 | * Check max730x.c for further details. |
12 | * 28 GPIOs. 8 of them can trigger an interrupt. See datasheet for more | ||
13 | * details | ||
14 | * Note: | ||
15 | * - DIN must be stable at the rising edge of clock. | ||
16 | * - when writing: | ||
17 | * - always clock in 16 clocks at once | ||
18 | * - at DIN: D15 first, D0 last | ||
19 | * - D0..D7 = databyte, D8..D14 = commandbyte | ||
20 | * - D15 = low -> write command | ||
21 | * - when reading | ||
22 | * - always clock in 16 clocks at once | ||
23 | * - at DIN: D15 first, D0 last | ||
24 | * - D0..D7 = dummy, D8..D14 = register address | ||
25 | * - D15 = high -> read command | ||
26 | * - raise CS and assert it again | ||
27 | * - always clock in 16 clocks at once | ||
28 | * - at DOUT: D15 first, D0 last | ||
29 | * - D0..D7 contains the data from the first cycle | ||
30 | * | ||
31 | * The driver exports a standard gpiochip interface | ||
32 | */ | 13 | */ |
33 | 14 | ||
15 | #include <linux/module.h> | ||
34 | #include <linux/init.h> | 16 | #include <linux/init.h> |
35 | #include <linux/platform_device.h> | 17 | #include <linux/platform_device.h> |
36 | #include <linux/mutex.h> | 18 | #include <linux/mutex.h> |
37 | #include <linux/spi/spi.h> | 19 | #include <linux/spi/spi.h> |
38 | #include <linux/spi/max7301.h> | 20 | #include <linux/spi/max7301.h> |
39 | #include <linux/gpio.h> | ||
40 | |||
41 | #define DRIVER_NAME "max7301" | ||
42 | |||
43 | /* | ||
44 | * Pin configurations, see MAX7301 datasheet page 6 | ||
45 | */ | ||
46 | #define PIN_CONFIG_MASK 0x03 | ||
47 | #define PIN_CONFIG_IN_PULLUP 0x03 | ||
48 | #define PIN_CONFIG_IN_WO_PULLUP 0x02 | ||
49 | #define PIN_CONFIG_OUT 0x01 | ||
50 | |||
51 | #define PIN_NUMBER 28 | ||
52 | |||
53 | |||
54 | /* | ||
55 | * Some registers must be read back to modify. | ||
56 | * To save time we cache them here in memory | ||
57 | */ | ||
58 | struct max7301 { | ||
59 | struct mutex lock; | ||
60 | u8 port_config[8]; /* field 0 is unused */ | ||
61 | u32 out_level; /* cached output levels */ | ||
62 | struct gpio_chip chip; | ||
63 | struct spi_device *spi; | ||
64 | }; | ||
65 | 21 | ||
66 | /** | 22 | /* A write to the MAX7301 means one message with one transfer */ |
67 | * max7301_write - Write a new register content | 23 | static int max7301_spi_write(struct device *dev, unsigned int reg, |
68 | * @spi: The SPI device | 24 | unsigned int val) |
69 | * @reg: Register offset | ||
70 | * @val: Value to write | ||
71 | * | ||
72 | * A write to the MAX7301 means one message with one transfer | ||
73 | * | ||
74 | * Returns 0 if successful or a negative value on error | ||
75 | */ | ||
76 | static int max7301_write(struct spi_device *spi, unsigned int reg, unsigned int val) | ||
77 | { | 25 | { |
26 | struct spi_device *spi = to_spi_device(dev); | ||
78 | u16 word = ((reg & 0x7F) << 8) | (val & 0xFF); | 27 | u16 word = ((reg & 0x7F) << 8) | (val & 0xFF); |
28 | |||
79 | return spi_write(spi, (const u8 *)&word, sizeof(word)); | 29 | return spi_write(spi, (const u8 *)&word, sizeof(word)); |
80 | } | 30 | } |
81 | 31 | ||
82 | /** | 32 | /* A read from the MAX7301 means two transfers; here, one message each */ |
83 | * max7301_read - Read back register content | 33 | |
84 | * @spi: The SPI device | 34 | static int max7301_spi_read(struct device *dev, unsigned int reg) |
85 | * @reg: Register offset | ||
86 | * | ||
87 | * A read from the MAX7301 means two transfers; here, one message each | ||
88 | * | ||
89 | * Returns positive 8 bit value from device if successful or a | ||
90 | * negative value on error | ||
91 | */ | ||
92 | static int max7301_read(struct spi_device *spi, unsigned int reg) | ||
93 | { | 35 | { |
94 | int ret; | 36 | int ret; |
95 | u16 word; | 37 | u16 word; |
38 | struct spi_device *spi = to_spi_device(dev); | ||
96 | 39 | ||
97 | word = 0x8000 | (reg << 8); | 40 | word = 0x8000 | (reg << 8); |
98 | ret = spi_write(spi, (const u8 *)&word, sizeof(word)); | 41 | ret = spi_write(spi, (const u8 *)&word, sizeof(word)); |
@@ -108,125 +51,13 @@ static int max7301_read(struct spi_device *spi, unsigned int reg) | |||
108 | return word & 0xff; | 51 | return word & 0xff; |
109 | } | 52 | } |
110 | 53 | ||
111 | static int max7301_direction_input(struct gpio_chip *chip, unsigned offset) | ||
112 | { | ||
113 | struct max7301 *ts = container_of(chip, struct max7301, chip); | ||
114 | u8 *config; | ||
115 | int ret; | ||
116 | |||
117 | /* First 4 pins are unused in the controller */ | ||
118 | offset += 4; | ||
119 | |||
120 | config = &ts->port_config[offset >> 2]; | ||
121 | |||
122 | mutex_lock(&ts->lock); | ||
123 | |||
124 | /* Standard GPIO API doesn't support pull-ups, has to be extended. | ||
125 | * Hard-coding no pollup for now. */ | ||
126 | *config = (*config & ~(3 << (offset & 3))) | (1 << (offset & 3)); | ||
127 | |||
128 | ret = max7301_write(ts->spi, 0x08 + (offset >> 2), *config); | ||
129 | |||
130 | mutex_unlock(&ts->lock); | ||
131 | |||
132 | return ret; | ||
133 | } | ||
134 | |||
135 | static int __max7301_set(struct max7301 *ts, unsigned offset, int value) | ||
136 | { | ||
137 | if (value) { | ||
138 | ts->out_level |= 1 << offset; | ||
139 | return max7301_write(ts->spi, 0x20 + offset, 0x01); | ||
140 | } else { | ||
141 | ts->out_level &= ~(1 << offset); | ||
142 | return max7301_write(ts->spi, 0x20 + offset, 0x00); | ||
143 | } | ||
144 | } | ||
145 | |||
146 | static int max7301_direction_output(struct gpio_chip *chip, unsigned offset, | ||
147 | int value) | ||
148 | { | ||
149 | struct max7301 *ts = container_of(chip, struct max7301, chip); | ||
150 | u8 *config; | ||
151 | int ret; | ||
152 | |||
153 | /* First 4 pins are unused in the controller */ | ||
154 | offset += 4; | ||
155 | |||
156 | config = &ts->port_config[offset >> 2]; | ||
157 | |||
158 | mutex_lock(&ts->lock); | ||
159 | |||
160 | *config = (*config & ~(3 << (offset & 3))) | (1 << (offset & 3)); | ||
161 | |||
162 | ret = __max7301_set(ts, offset, value); | ||
163 | |||
164 | if (!ret) | ||
165 | ret = max7301_write(ts->spi, 0x08 + (offset >> 2), *config); | ||
166 | |||
167 | mutex_unlock(&ts->lock); | ||
168 | |||
169 | return ret; | ||
170 | } | ||
171 | |||
172 | static int max7301_get(struct gpio_chip *chip, unsigned offset) | ||
173 | { | ||
174 | struct max7301 *ts = container_of(chip, struct max7301, chip); | ||
175 | int config, level = -EINVAL; | ||
176 | |||
177 | /* First 4 pins are unused in the controller */ | ||
178 | offset += 4; | ||
179 | |||
180 | mutex_lock(&ts->lock); | ||
181 | |||
182 | config = (ts->port_config[offset >> 2] >> ((offset & 3) * 2)) & 3; | ||
183 | |||
184 | switch (config) { | ||
185 | case 1: | ||
186 | /* Output: return cached level */ | ||
187 | level = !!(ts->out_level & (1 << offset)); | ||
188 | break; | ||
189 | case 2: | ||
190 | case 3: | ||
191 | /* Input: read out */ | ||
192 | level = max7301_read(ts->spi, 0x20 + offset) & 0x01; | ||
193 | } | ||
194 | mutex_unlock(&ts->lock); | ||
195 | |||
196 | return level; | ||
197 | } | ||
198 | |||
199 | static void max7301_set(struct gpio_chip *chip, unsigned offset, int value) | ||
200 | { | ||
201 | struct max7301 *ts = container_of(chip, struct max7301, chip); | ||
202 | |||
203 | /* First 4 pins are unused in the controller */ | ||
204 | offset += 4; | ||
205 | |||
206 | mutex_lock(&ts->lock); | ||
207 | |||
208 | __max7301_set(ts, offset, value); | ||
209 | |||
210 | mutex_unlock(&ts->lock); | ||
211 | } | ||
212 | |||
213 | static int __devinit max7301_probe(struct spi_device *spi) | 54 | static int __devinit max7301_probe(struct spi_device *spi) |
214 | { | 55 | { |
215 | struct max7301 *ts; | 56 | struct max7301 *ts; |
216 | struct max7301_platform_data *pdata; | 57 | int ret; |
217 | int i, ret; | ||
218 | |||
219 | pdata = spi->dev.platform_data; | ||
220 | if (!pdata || !pdata->base) { | ||
221 | dev_dbg(&spi->dev, "incorrect or missing platform data\n"); | ||
222 | return -EINVAL; | ||
223 | } | ||
224 | 58 | ||
225 | /* | 59 | /* bits_per_word cannot be configured in platform data */ |
226 | * bits_per_word cannot be configured in platform data | ||
227 | */ | ||
228 | spi->bits_per_word = 16; | 60 | spi->bits_per_word = 16; |
229 | |||
230 | ret = spi_setup(spi); | 61 | ret = spi_setup(spi); |
231 | if (ret < 0) | 62 | if (ret < 0) |
232 | return ret; | 63 | return ret; |
@@ -235,90 +66,35 @@ static int __devinit max7301_probe(struct spi_device *spi) | |||
235 | if (!ts) | 66 | if (!ts) |
236 | return -ENOMEM; | 67 | return -ENOMEM; |
237 | 68 | ||
238 | mutex_init(&ts->lock); | 69 | ts->read = max7301_spi_read; |
239 | 70 | ts->write = max7301_spi_write; | |
240 | dev_set_drvdata(&spi->dev, ts); | 71 | ts->dev = &spi->dev; |
241 | 72 | ||
242 | /* Power up the chip and disable IRQ output */ | 73 | ret = __max730x_probe(ts); |
243 | max7301_write(spi, 0x04, 0x01); | ||
244 | |||
245 | ts->spi = spi; | ||
246 | |||
247 | ts->chip.label = DRIVER_NAME, | ||
248 | |||
249 | ts->chip.direction_input = max7301_direction_input; | ||
250 | ts->chip.get = max7301_get; | ||
251 | ts->chip.direction_output = max7301_direction_output; | ||
252 | ts->chip.set = max7301_set; | ||
253 | |||
254 | ts->chip.base = pdata->base; | ||
255 | ts->chip.ngpio = PIN_NUMBER; | ||
256 | ts->chip.can_sleep = 1; | ||
257 | ts->chip.dev = &spi->dev; | ||
258 | ts->chip.owner = THIS_MODULE; | ||
259 | |||
260 | /* | ||
261 | * tristate all pins in hardware and cache the | ||
262 | * register values for later use. | ||
263 | */ | ||
264 | for (i = 1; i < 8; i++) { | ||
265 | int j; | ||
266 | /* 0xAA means input with internal pullup disabled */ | ||
267 | max7301_write(spi, 0x08 + i, 0xAA); | ||
268 | ts->port_config[i] = 0xAA; | ||
269 | for (j = 0; j < 4; j++) { | ||
270 | int offset = (i - 1) * 4 + j; | ||
271 | ret = max7301_direction_input(&ts->chip, offset); | ||
272 | if (ret) | ||
273 | goto exit_destroy; | ||
274 | } | ||
275 | } | ||
276 | |||
277 | ret = gpiochip_add(&ts->chip); | ||
278 | if (ret) | 74 | if (ret) |
279 | goto exit_destroy; | 75 | kfree(ts); |
280 | |||
281 | return ret; | ||
282 | |||
283 | exit_destroy: | ||
284 | dev_set_drvdata(&spi->dev, NULL); | ||
285 | mutex_destroy(&ts->lock); | ||
286 | kfree(ts); | ||
287 | return ret; | 76 | return ret; |
288 | } | 77 | } |
289 | 78 | ||
290 | static int __devexit max7301_remove(struct spi_device *spi) | 79 | static int __devexit max7301_remove(struct spi_device *spi) |
291 | { | 80 | { |
292 | struct max7301 *ts; | 81 | return __max730x_remove(&spi->dev); |
293 | int ret; | ||
294 | |||
295 | ts = dev_get_drvdata(&spi->dev); | ||
296 | if (ts == NULL) | ||
297 | return -ENODEV; | ||
298 | |||
299 | dev_set_drvdata(&spi->dev, NULL); | ||
300 | |||
301 | /* Power down the chip and disable IRQ output */ | ||
302 | max7301_write(spi, 0x04, 0x00); | ||
303 | |||
304 | ret = gpiochip_remove(&ts->chip); | ||
305 | if (!ret) { | ||
306 | mutex_destroy(&ts->lock); | ||
307 | kfree(ts); | ||
308 | } else | ||
309 | dev_err(&spi->dev, "Failed to remove the GPIO controller: %d\n", | ||
310 | ret); | ||
311 | |||
312 | return ret; | ||
313 | } | 82 | } |
314 | 83 | ||
84 | static const struct spi_device_id max7301_id[] = { | ||
85 | { "max7301", 0 }, | ||
86 | { } | ||
87 | }; | ||
88 | MODULE_DEVICE_TABLE(spi, max7301_id); | ||
89 | |||
315 | static struct spi_driver max7301_driver = { | 90 | static struct spi_driver max7301_driver = { |
316 | .driver = { | 91 | .driver = { |
317 | .name = DRIVER_NAME, | 92 | .name = "max7301", |
318 | .owner = THIS_MODULE, | 93 | .owner = THIS_MODULE, |
319 | }, | 94 | }, |
320 | .probe = max7301_probe, | 95 | .probe = max7301_probe, |
321 | .remove = __devexit_p(max7301_remove), | 96 | .remove = __devexit_p(max7301_remove), |
97 | .id_table = max7301_id, | ||
322 | }; | 98 | }; |
323 | 99 | ||
324 | static int __init max7301_init(void) | 100 | static int __init max7301_init(void) |
@@ -336,7 +112,6 @@ static void __exit max7301_exit(void) | |||
336 | } | 112 | } |
337 | module_exit(max7301_exit); | 113 | module_exit(max7301_exit); |
338 | 114 | ||
339 | MODULE_AUTHOR("Juergen Beisert"); | 115 | MODULE_AUTHOR("Juergen Beisert, Wolfram Sang"); |
340 | MODULE_LICENSE("GPL v2"); | 116 | MODULE_LICENSE("GPL v2"); |
341 | MODULE_DESCRIPTION("MAX7301 SPI based GPIO-Expander"); | 117 | MODULE_DESCRIPTION("MAX7301 GPIO-Expander"); |
342 | MODULE_ALIAS("spi:" DRIVER_NAME); | ||
diff --git a/drivers/gpio/max730x.c b/drivers/gpio/max730x.c new file mode 100644 index 000000000000..c9bced55f82b --- /dev/null +++ b/drivers/gpio/max730x.c | |||
@@ -0,0 +1,244 @@ | |||
1 | /** | ||
2 | * drivers/gpio/max7301.c | ||
3 | * | ||
4 | * Copyright (C) 2006 Juergen Beisert, Pengutronix | ||
5 | * Copyright (C) 2008 Guennadi Liakhovetski, Pengutronix | ||
6 | * Copyright (C) 2009 Wolfram Sang, Pengutronix | ||
7 | * | ||
8 | * This program is free software; you can redistribute it and/or modify | ||
9 | * it under the terms of the GNU General Public License version 2 as | ||
10 | * published by the Free Software Foundation. | ||
11 | * | ||
12 | * The Maxim MAX7300/1 device is an I2C/SPI driven GPIO expander. There are | ||
13 | * 28 GPIOs. 8 of them can trigger an interrupt. See datasheet for more | ||
14 | * details | ||
15 | * Note: | ||
16 | * - DIN must be stable at the rising edge of clock. | ||
17 | * - when writing: | ||
18 | * - always clock in 16 clocks at once | ||
19 | * - at DIN: D15 first, D0 last | ||
20 | * - D0..D7 = databyte, D8..D14 = commandbyte | ||
21 | * - D15 = low -> write command | ||
22 | * - when reading | ||
23 | * - always clock in 16 clocks at once | ||
24 | * - at DIN: D15 first, D0 last | ||
25 | * - D0..D7 = dummy, D8..D14 = register address | ||
26 | * - D15 = high -> read command | ||
27 | * - raise CS and assert it again | ||
28 | * - always clock in 16 clocks at once | ||
29 | * - at DOUT: D15 first, D0 last | ||
30 | * - D0..D7 contains the data from the first cycle | ||
31 | * | ||
32 | * The driver exports a standard gpiochip interface | ||
33 | */ | ||
34 | |||
35 | #include <linux/module.h> | ||
36 | #include <linux/init.h> | ||
37 | #include <linux/platform_device.h> | ||
38 | #include <linux/mutex.h> | ||
39 | #include <linux/spi/max7301.h> | ||
40 | #include <linux/gpio.h> | ||
41 | |||
42 | /* | ||
43 | * Pin configurations, see MAX7301 datasheet page 6 | ||
44 | */ | ||
45 | #define PIN_CONFIG_MASK 0x03 | ||
46 | #define PIN_CONFIG_IN_PULLUP 0x03 | ||
47 | #define PIN_CONFIG_IN_WO_PULLUP 0x02 | ||
48 | #define PIN_CONFIG_OUT 0x01 | ||
49 | |||
50 | #define PIN_NUMBER 28 | ||
51 | |||
52 | static int max7301_direction_input(struct gpio_chip *chip, unsigned offset) | ||
53 | { | ||
54 | struct max7301 *ts = container_of(chip, struct max7301, chip); | ||
55 | u8 *config; | ||
56 | u8 offset_bits; | ||
57 | int ret; | ||
58 | |||
59 | /* First 4 pins are unused in the controller */ | ||
60 | offset += 4; | ||
61 | offset_bits = (offset & 3) << 1; | ||
62 | |||
63 | config = &ts->port_config[offset >> 2]; | ||
64 | |||
65 | mutex_lock(&ts->lock); | ||
66 | |||
67 | /* Standard GPIO API doesn't support pull-ups, has to be extended. | ||
68 | * Hard-coding no pollup for now. */ | ||
69 | *config = (*config & ~(PIN_CONFIG_MASK << offset_bits)) | ||
70 | | (PIN_CONFIG_IN_WO_PULLUP << offset_bits); | ||
71 | |||
72 | ret = ts->write(ts->dev, 0x08 + (offset >> 2), *config); | ||
73 | |||
74 | mutex_unlock(&ts->lock); | ||
75 | |||
76 | return ret; | ||
77 | } | ||
78 | |||
79 | static int __max7301_set(struct max7301 *ts, unsigned offset, int value) | ||
80 | { | ||
81 | if (value) { | ||
82 | ts->out_level |= 1 << offset; | ||
83 | return ts->write(ts->dev, 0x20 + offset, 0x01); | ||
84 | } else { | ||
85 | ts->out_level &= ~(1 << offset); | ||
86 | return ts->write(ts->dev, 0x20 + offset, 0x00); | ||
87 | } | ||
88 | } | ||
89 | |||
90 | static int max7301_direction_output(struct gpio_chip *chip, unsigned offset, | ||
91 | int value) | ||
92 | { | ||
93 | struct max7301 *ts = container_of(chip, struct max7301, chip); | ||
94 | u8 *config; | ||
95 | u8 offset_bits; | ||
96 | int ret; | ||
97 | |||
98 | /* First 4 pins are unused in the controller */ | ||
99 | offset += 4; | ||
100 | offset_bits = (offset & 3) << 1; | ||
101 | |||
102 | config = &ts->port_config[offset >> 2]; | ||
103 | |||
104 | mutex_lock(&ts->lock); | ||
105 | |||
106 | *config = (*config & ~(PIN_CONFIG_MASK << offset_bits)) | ||
107 | | (PIN_CONFIG_OUT << offset_bits); | ||
108 | |||
109 | ret = __max7301_set(ts, offset, value); | ||
110 | |||
111 | if (!ret) | ||
112 | ret = ts->write(ts->dev, 0x08 + (offset >> 2), *config); | ||
113 | |||
114 | mutex_unlock(&ts->lock); | ||
115 | |||
116 | return ret; | ||
117 | } | ||
118 | |||
119 | static int max7301_get(struct gpio_chip *chip, unsigned offset) | ||
120 | { | ||
121 | struct max7301 *ts = container_of(chip, struct max7301, chip); | ||
122 | int config, level = -EINVAL; | ||
123 | |||
124 | /* First 4 pins are unused in the controller */ | ||
125 | offset += 4; | ||
126 | |||
127 | mutex_lock(&ts->lock); | ||
128 | |||
129 | config = (ts->port_config[offset >> 2] >> ((offset & 3) << 1)) | ||
130 | & PIN_CONFIG_MASK; | ||
131 | |||
132 | switch (config) { | ||
133 | case PIN_CONFIG_OUT: | ||
134 | /* Output: return cached level */ | ||
135 | level = !!(ts->out_level & (1 << offset)); | ||
136 | break; | ||
137 | case PIN_CONFIG_IN_WO_PULLUP: | ||
138 | case PIN_CONFIG_IN_PULLUP: | ||
139 | /* Input: read out */ | ||
140 | level = ts->read(ts->dev, 0x20 + offset) & 0x01; | ||
141 | } | ||
142 | mutex_unlock(&ts->lock); | ||
143 | |||
144 | return level; | ||
145 | } | ||
146 | |||
147 | static void max7301_set(struct gpio_chip *chip, unsigned offset, int value) | ||
148 | { | ||
149 | struct max7301 *ts = container_of(chip, struct max7301, chip); | ||
150 | |||
151 | /* First 4 pins are unused in the controller */ | ||
152 | offset += 4; | ||
153 | |||
154 | mutex_lock(&ts->lock); | ||
155 | |||
156 | __max7301_set(ts, offset, value); | ||
157 | |||
158 | mutex_unlock(&ts->lock); | ||
159 | } | ||
160 | |||
161 | int __devinit __max730x_probe(struct max7301 *ts) | ||
162 | { | ||
163 | struct device *dev = ts->dev; | ||
164 | struct max7301_platform_data *pdata; | ||
165 | int i, ret; | ||
166 | |||
167 | pdata = dev->platform_data; | ||
168 | if (!pdata || !pdata->base) { | ||
169 | dev_err(dev, "incorrect or missing platform data\n"); | ||
170 | return -EINVAL; | ||
171 | } | ||
172 | |||
173 | mutex_init(&ts->lock); | ||
174 | dev_set_drvdata(dev, ts); | ||
175 | |||
176 | /* Power up the chip and disable IRQ output */ | ||
177 | ts->write(dev, 0x04, 0x01); | ||
178 | |||
179 | ts->chip.label = dev->driver->name; | ||
180 | |||
181 | ts->chip.direction_input = max7301_direction_input; | ||
182 | ts->chip.get = max7301_get; | ||
183 | ts->chip.direction_output = max7301_direction_output; | ||
184 | ts->chip.set = max7301_set; | ||
185 | |||
186 | ts->chip.base = pdata->base; | ||
187 | ts->chip.ngpio = PIN_NUMBER; | ||
188 | ts->chip.can_sleep = 1; | ||
189 | ts->chip.dev = dev; | ||
190 | ts->chip.owner = THIS_MODULE; | ||
191 | |||
192 | /* | ||
193 | * tristate all pins in hardware and cache the | ||
194 | * register values for later use. | ||
195 | */ | ||
196 | for (i = 1; i < 8; i++) { | ||
197 | int j; | ||
198 | /* 0xAA means input with internal pullup disabled */ | ||
199 | ts->write(dev, 0x08 + i, 0xAA); | ||
200 | ts->port_config[i] = 0xAA; | ||
201 | for (j = 0; j < 4; j++) { | ||
202 | int offset = (i - 1) * 4 + j; | ||
203 | ret = max7301_direction_input(&ts->chip, offset); | ||
204 | if (ret) | ||
205 | goto exit_destroy; | ||
206 | } | ||
207 | } | ||
208 | |||
209 | ret = gpiochip_add(&ts->chip); | ||
210 | if (ret) | ||
211 | goto exit_destroy; | ||
212 | |||
213 | return ret; | ||
214 | |||
215 | exit_destroy: | ||
216 | dev_set_drvdata(dev, NULL); | ||
217 | mutex_destroy(&ts->lock); | ||
218 | return ret; | ||
219 | } | ||
220 | EXPORT_SYMBOL_GPL(__max730x_probe); | ||
221 | |||
222 | int __devexit __max730x_remove(struct device *dev) | ||
223 | { | ||
224 | struct max7301 *ts = dev_get_drvdata(dev); | ||
225 | int ret; | ||
226 | |||
227 | if (ts == NULL) | ||
228 | return -ENODEV; | ||
229 | |||
230 | dev_set_drvdata(dev, NULL); | ||
231 | |||
232 | /* Power down the chip and disable IRQ output */ | ||
233 | ts->write(dev, 0x04, 0x00); | ||
234 | |||
235 | ret = gpiochip_remove(&ts->chip); | ||
236 | if (!ret) { | ||
237 | mutex_destroy(&ts->lock); | ||
238 | kfree(ts); | ||
239 | } else | ||
240 | dev_err(dev, "Failed to remove GPIO controller: %d\n", ret); | ||
241 | |||
242 | return ret; | ||
243 | } | ||
244 | EXPORT_SYMBOL_GPL(__max730x_remove); | ||