From e952805d2d2e706aed182723e5ab3ec0b1f91de3 Mon Sep 17 00:00:00 2001 From: Wolfram Sang Date: Fri, 5 Mar 2010 13:44:33 -0800 Subject: [PATCH] gpio: add driver for MAX7300 I2C GPIO extender Add the MAX7300-I2C variant of the MAX7301-SPI version. Both chips share the same core logic, so the generic part of the in-kernel SPI-driver is refactored into a generic part. The I2C and SPI specific funtions are then wrapped into seperate drivers picking up the generic part. Signed-off-by: Wolfram Sang Cc: Juergen Beisert Cc: David Brownell Cc: Jean Delvare Cc: Anton Vorontsov Cc: Randy Dunlap Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/gpio/Kconfig | 13 +- drivers/gpio/Makefile | 2 + drivers/gpio/max7300.c | 94 ++++++++++++ drivers/gpio/max7301.c | 293 +++++------------------------------- drivers/gpio/max730x.c | 244 ++++++++++++++++++++++++++++++ include/linux/spi/max7301.h | 18 +++ 6 files changed, 404 insertions(+), 260 deletions(-) create mode 100644 drivers/gpio/max7300.c create mode 100644 drivers/gpio/max730x.c 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 # put expanders in the right section, in alphabetical order +config GPIO_MAX730X + tristate + comment "Memory mapped GPIO expanders:" config GPIO_PL061 @@ -87,6 +90,13 @@ config GPIO_VR41XX comment "I2C GPIO expanders:" +config GPIO_MAX7300 + tristate "Maxim MAX7300 GPIO expander" + depends on I2C + select GPIO_MAX730X + help + GPIO driver for Maxim MAX7301 I2C-based GPIO expander. + config GPIO_MAX732X tristate "MAX7319, MAX7320-7327 I2C Port Expanders" depends on I2C @@ -226,8 +236,9 @@ comment "SPI GPIO expanders:" config GPIO_MAX7301 tristate "Maxim MAX7301 GPIO expander" depends on SPI_MASTER + select GPIO_MAX730X help - gpio driver for Maxim MAX7301 SPI GPIO expander. + GPIO driver for Maxim MAX7301 SPI-based GPIO expander. config GPIO_MCP23S08 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-$(CONFIG_GPIOLIB) += gpiolib.o obj-$(CONFIG_GPIO_ADP5520) += adp5520-gpio.o obj-$(CONFIG_GPIO_ADP5588) += adp5588-gpio.o obj-$(CONFIG_GPIO_LANGWELL) += langwell_gpio.o +obj-$(CONFIG_GPIO_MAX730X) += max730x.o +obj-$(CONFIG_GPIO_MAX7300) += max7300.o obj-$(CONFIG_GPIO_MAX7301) += max7301.o obj-$(CONFIG_GPIO_MAX732X) += max732x.o 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 @@ +/* + * drivers/gpio/max7300.c + * + * Copyright (C) 2009 Wolfram Sang, Pengutronix + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * Check max730x.c for further details. + */ + +#include +#include +#include +#include +#include +#include + +static int max7300_i2c_write(struct device *dev, unsigned int reg, + unsigned int val) +{ + struct i2c_client *client = to_i2c_client(dev); + + return i2c_smbus_write_byte_data(client, reg, val); +} + +static int max7300_i2c_read(struct device *dev, unsigned int reg) +{ + struct i2c_client *client = to_i2c_client(dev); + + return i2c_smbus_read_byte_data(client, reg); +} + +static int __devinit max7300_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct max7301 *ts; + int ret; + + if (!i2c_check_functionality(client->adapter, + I2C_FUNC_SMBUS_BYTE_DATA)) + return -EIO; + + ts = kzalloc(sizeof(struct max7301), GFP_KERNEL); + if (!ts) + return -ENOMEM; + + ts->read = max7300_i2c_read; + ts->write = max7300_i2c_write; + ts->dev = &client->dev; + + ret = __max730x_probe(ts); + if (ret) + kfree(ts); + return ret; +} + +static int __devexit max7300_remove(struct i2c_client *client) +{ + return __max730x_remove(&client->dev); +} + +static const struct i2c_device_id max7300_id[] = { + { "max7300", 0 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, max7300_id); + +static struct i2c_driver max7300_driver = { + .driver = { + .name = "max7300", + .owner = THIS_MODULE, + }, + .probe = max7300_probe, + .remove = __devexit_p(max7300_remove), + .id_table = max7300_id, +}; + +static int __init max7300_init(void) +{ + return i2c_add_driver(&max7300_driver); +} +subsys_initcall(max7300_init); + +static void __exit max7300_exit(void) +{ + i2c_del_driver(&max7300_driver); +} +module_exit(max7300_exit); + +MODULE_AUTHOR("Wolfram Sang"); +MODULE_LICENSE("GPL v2"); +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 @@ -/** +/* * drivers/gpio/max7301.c * * Copyright (C) 2006 Juergen Beisert, Pengutronix * Copyright (C) 2008 Guennadi Liakhovetski, Pengutronix + * Copyright (C) 2009 Wolfram Sang, Pengutronix * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * - * The Maxim's MAX7301 device is an SPI driven GPIO expander. There are - * 28 GPIOs. 8 of them can trigger an interrupt. See datasheet for more - * details - * Note: - * - DIN must be stable at the rising edge of clock. - * - when writing: - * - always clock in 16 clocks at once - * - at DIN: D15 first, D0 last - * - D0..D7 = databyte, D8..D14 = commandbyte - * - D15 = low -> write command - * - when reading - * - always clock in 16 clocks at once - * - at DIN: D15 first, D0 last - * - D0..D7 = dummy, D8..D14 = register address - * - D15 = high -> read command - * - raise CS and assert it again - * - always clock in 16 clocks at once - * - at DOUT: D15 first, D0 last - * - D0..D7 contains the data from the first cycle - * - * The driver exports a standard gpiochip interface + * Check max730x.c for further details. */ +#include #include #include #include #include #include -#include - -#define DRIVER_NAME "max7301" - -/* - * Pin configurations, see MAX7301 datasheet page 6 - */ -#define PIN_CONFIG_MASK 0x03 -#define PIN_CONFIG_IN_PULLUP 0x03 -#define PIN_CONFIG_IN_WO_PULLUP 0x02 -#define PIN_CONFIG_OUT 0x01 - -#define PIN_NUMBER 28 - - -/* - * Some registers must be read back to modify. - * To save time we cache them here in memory - */ -struct max7301 { - struct mutex lock; - u8 port_config[8]; /* field 0 is unused */ - u32 out_level; /* cached output levels */ - struct gpio_chip chip; - struct spi_device *spi; -}; -/** - * max7301_write - Write a new register content - * @spi: The SPI device - * @reg: Register offset - * @val: Value to write - * - * A write to the MAX7301 means one message with one transfer - * - * Returns 0 if successful or a negative value on error - */ -static int max7301_write(struct spi_device *spi, unsigned int reg, unsigned int val) +/* A write to the MAX7301 means one message with one transfer */ +static int max7301_spi_write(struct device *dev, unsigned int reg, + unsigned int val) { + struct spi_device *spi = to_spi_device(dev); u16 word = ((reg & 0x7F) << 8) | (val & 0xFF); + return spi_write(spi, (const u8 *)&word, sizeof(word)); } -/** - * max7301_read - Read back register content - * @spi: The SPI device - * @reg: Register offset - * - * A read from the MAX7301 means two transfers; here, one message each - * - * Returns positive 8 bit value from device if successful or a - * negative value on error - */ -static int max7301_read(struct spi_device *spi, unsigned int reg) +/* A read from the MAX7301 means two transfers; here, one message each */ + +static int max7301_spi_read(struct device *dev, unsigned int reg) { int ret; u16 word; + struct spi_device *spi = to_spi_device(dev); word = 0x8000 | (reg << 8); ret = spi_write(spi, (const u8 *)&word, sizeof(word)); @@ -108,125 +51,13 @@ static int max7301_read(struct spi_device *spi, unsigned int reg) return word & 0xff; } -static int max7301_direction_input(struct gpio_chip *chip, unsigned offset) -{ - struct max7301 *ts = container_of(chip, struct max7301, chip); - u8 *config; - int ret; - - /* First 4 pins are unused in the controller */ - offset += 4; - - config = &ts->port_config[offset >> 2]; - - mutex_lock(&ts->lock); - - /* Standard GPIO API doesn't support pull-ups, has to be extended. - * Hard-coding no pollup for now. */ - *config = (*config & ~(3 << (offset & 3))) | (1 << (offset & 3)); - - ret = max7301_write(ts->spi, 0x08 + (offset >> 2), *config); - - mutex_unlock(&ts->lock); - - return ret; -} - -static int __max7301_set(struct max7301 *ts, unsigned offset, int value) -{ - if (value) { - ts->out_level |= 1 << offset; - return max7301_write(ts->spi, 0x20 + offset, 0x01); - } else { - ts->out_level &= ~(1 << offset); - return max7301_write(ts->spi, 0x20 + offset, 0x00); - } -} - -static int max7301_direction_output(struct gpio_chip *chip, unsigned offset, - int value) -{ - struct max7301 *ts = container_of(chip, struct max7301, chip); - u8 *config; - int ret; - - /* First 4 pins are unused in the controller */ - offset += 4; - - config = &ts->port_config[offset >> 2]; - - mutex_lock(&ts->lock); - - *config = (*config & ~(3 << (offset & 3))) | (1 << (offset & 3)); - - ret = __max7301_set(ts, offset, value); - - if (!ret) - ret = max7301_write(ts->spi, 0x08 + (offset >> 2), *config); - - mutex_unlock(&ts->lock); - - return ret; -} - -static int max7301_get(struct gpio_chip *chip, unsigned offset) -{ - struct max7301 *ts = container_of(chip, struct max7301, chip); - int config, level = -EINVAL; - - /* First 4 pins are unused in the controller */ - offset += 4; - - mutex_lock(&ts->lock); - - config = (ts->port_config[offset >> 2] >> ((offset & 3) * 2)) & 3; - - switch (config) { - case 1: - /* Output: return cached level */ - level = !!(ts->out_level & (1 << offset)); - break; - case 2: - case 3: - /* Input: read out */ - level = max7301_read(ts->spi, 0x20 + offset) & 0x01; - } - mutex_unlock(&ts->lock); - - return level; -} - -static void max7301_set(struct gpio_chip *chip, unsigned offset, int value) -{ - struct max7301 *ts = container_of(chip, struct max7301, chip); - - /* First 4 pins are unused in the controller */ - offset += 4; - - mutex_lock(&ts->lock); - - __max7301_set(ts, offset, value); - - mutex_unlock(&ts->lock); -} - static int __devinit max7301_probe(struct spi_device *spi) { struct max7301 *ts; - struct max7301_platform_data *pdata; - int i, ret; - - pdata = spi->dev.platform_data; - if (!pdata || !pdata->base) { - dev_dbg(&spi->dev, "incorrect or missing platform data\n"); - return -EINVAL; - } + int ret; - /* - * bits_per_word cannot be configured in platform data - */ + /* bits_per_word cannot be configured in platform data */ spi->bits_per_word = 16; - ret = spi_setup(spi); if (ret < 0) return ret; @@ -235,90 +66,35 @@ static int __devinit max7301_probe(struct spi_device *spi) if (!ts) return -ENOMEM; - mutex_init(&ts->lock); - - dev_set_drvdata(&spi->dev, ts); + ts->read = max7301_spi_read; + ts->write = max7301_spi_write; + ts->dev = &spi->dev; - /* Power up the chip and disable IRQ output */ - max7301_write(spi, 0x04, 0x01); - - ts->spi = spi; - - ts->chip.label = DRIVER_NAME, - - ts->chip.direction_input = max7301_direction_input; - ts->chip.get = max7301_get; - ts->chip.direction_output = max7301_direction_output; - ts->chip.set = max7301_set; - - ts->chip.base = pdata->base; - ts->chip.ngpio = PIN_NUMBER; - ts->chip.can_sleep = 1; - ts->chip.dev = &spi->dev; - ts->chip.owner = THIS_MODULE; - - /* - * tristate all pins in hardware and cache the - * register values for later use. - */ - for (i = 1; i < 8; i++) { - int j; - /* 0xAA means input with internal pullup disabled */ - max7301_write(spi, 0x08 + i, 0xAA); - ts->port_config[i] = 0xAA; - for (j = 0; j < 4; j++) { - int offset = (i - 1) * 4 + j; - ret = max7301_direction_input(&ts->chip, offset); - if (ret) - goto exit_destroy; - } - } - - ret = gpiochip_add(&ts->chip); + ret = __max730x_probe(ts); if (ret) - goto exit_destroy; - - return ret; - -exit_destroy: - dev_set_drvdata(&spi->dev, NULL); - mutex_destroy(&ts->lock); - kfree(ts); + kfree(ts); return ret; } static int __devexit max7301_remove(struct spi_device *spi) { - struct max7301 *ts; - int ret; - - ts = dev_get_drvdata(&spi->dev); - if (ts == NULL) - return -ENODEV; - - dev_set_drvdata(&spi->dev, NULL); - - /* Power down the chip and disable IRQ output */ - max7301_write(spi, 0x04, 0x00); - - ret = gpiochip_remove(&ts->chip); - if (!ret) { - mutex_destroy(&ts->lock); - kfree(ts); - } else - dev_err(&spi->dev, "Failed to remove the GPIO controller: %d\n", - ret); - - return ret; + return __max730x_remove(&spi->dev); } +static const struct spi_device_id max7301_id[] = { + { "max7301", 0 }, + { } +}; +MODULE_DEVICE_TABLE(spi, max7301_id); + static struct spi_driver max7301_driver = { .driver = { - .name = DRIVER_NAME, - .owner = THIS_MODULE, + .name = "max7301", + .owner = THIS_MODULE, }, - .probe = max7301_probe, - .remove = __devexit_p(max7301_remove), + .probe = max7301_probe, + .remove = __devexit_p(max7301_remove), + .id_table = max7301_id, }; static int __init max7301_init(void) @@ -336,7 +112,6 @@ static void __exit max7301_exit(void) } module_exit(max7301_exit); -MODULE_AUTHOR("Juergen Beisert"); +MODULE_AUTHOR("Juergen Beisert, Wolfram Sang"); MODULE_LICENSE("GPL v2"); -MODULE_DESCRIPTION("MAX7301 SPI based GPIO-Expander"); -MODULE_ALIAS("spi:" DRIVER_NAME); +MODULE_DESCRIPTION("MAX7301 GPIO-Expander"); 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 @@ +/** + * drivers/gpio/max7301.c + * + * Copyright (C) 2006 Juergen Beisert, Pengutronix + * Copyright (C) 2008 Guennadi Liakhovetski, Pengutronix + * Copyright (C) 2009 Wolfram Sang, Pengutronix + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * The Maxim MAX7300/1 device is an I2C/SPI driven GPIO expander. There are + * 28 GPIOs. 8 of them can trigger an interrupt. See datasheet for more + * details + * Note: + * - DIN must be stable at the rising edge of clock. + * - when writing: + * - always clock in 16 clocks at once + * - at DIN: D15 first, D0 last + * - D0..D7 = databyte, D8..D14 = commandbyte + * - D15 = low -> write command + * - when reading + * - always clock in 16 clocks at once + * - at DIN: D15 first, D0 last + * - D0..D7 = dummy, D8..D14 = register address + * - D15 = high -> read command + * - raise CS and assert it again + * - always clock in 16 clocks at once + * - at DOUT: D15 first, D0 last + * - D0..D7 contains the data from the first cycle + * + * The driver exports a standard gpiochip interface + */ + +#include +#include +#include +#include +#include +#include + +/* + * Pin configurations, see MAX7301 datasheet page 6 + */ +#define PIN_CONFIG_MASK 0x03 +#define PIN_CONFIG_IN_PULLUP 0x03 +#define PIN_CONFIG_IN_WO_PULLUP 0x02 +#define PIN_CONFIG_OUT 0x01 + +#define PIN_NUMBER 28 + +static int max7301_direction_input(struct gpio_chip *chip, unsigned offset) +{ + struct max7301 *ts = container_of(chip, struct max7301, chip); + u8 *config; + u8 offset_bits; + int ret; + + /* First 4 pins are unused in the controller */ + offset += 4; + offset_bits = (offset & 3) << 1; + + config = &ts->port_config[offset >> 2]; + + mutex_lock(&ts->lock); + + /* Standard GPIO API doesn't support pull-ups, has to be extended. + * Hard-coding no pollup for now. */ + *config = (*config & ~(PIN_CONFIG_MASK << offset_bits)) + | (PIN_CONFIG_IN_WO_PULLUP << offset_bits); + + ret = ts->write(ts->dev, 0x08 + (offset >> 2), *config); + + mutex_unlock(&ts->lock); + + return ret; +} + +static int __max7301_set(struct max7301 *ts, unsigned offset, int value) +{ + if (value) { + ts->out_level |= 1 << offset; + return ts->write(ts->dev, 0x20 + offset, 0x01); + } else { + ts->out_level &= ~(1 << offset); + return ts->write(ts->dev, 0x20 + offset, 0x00); + } +} + +static int max7301_direction_output(struct gpio_chip *chip, unsigned offset, + int value) +{ + struct max7301 *ts = container_of(chip, struct max7301, chip); + u8 *config; + u8 offset_bits; + int ret; + + /* First 4 pins are unused in the controller */ + offset += 4; + offset_bits = (offset & 3) << 1; + + config = &ts->port_config[offset >> 2]; + + mutex_lock(&ts->lock); + + *config = (*config & ~(PIN_CONFIG_MASK << offset_bits)) + | (PIN_CONFIG_OUT << offset_bits); + + ret = __max7301_set(ts, offset, value); + + if (!ret) + ret = ts->write(ts->dev, 0x08 + (offset >> 2), *config); + + mutex_unlock(&ts->lock); + + return ret; +} + +static int max7301_get(struct gpio_chip *chip, unsigned offset) +{ + struct max7301 *ts = container_of(chip, struct max7301, chip); + int config, level = -EINVAL; + + /* First 4 pins are unused in the controller */ + offset += 4; + + mutex_lock(&ts->lock); + + config = (ts->port_config[offset >> 2] >> ((offset & 3) << 1)) + & PIN_CONFIG_MASK; + + switch (config) { + case PIN_CONFIG_OUT: + /* Output: return cached level */ + level = !!(ts->out_level & (1 << offset)); + break; + case PIN_CONFIG_IN_WO_PULLUP: + case PIN_CONFIG_IN_PULLUP: + /* Input: read out */ + level = ts->read(ts->dev, 0x20 + offset) & 0x01; + } + mutex_unlock(&ts->lock); + + return level; +} + +static void max7301_set(struct gpio_chip *chip, unsigned offset, int value) +{ + struct max7301 *ts = container_of(chip, struct max7301, chip); + + /* First 4 pins are unused in the controller */ + offset += 4; + + mutex_lock(&ts->lock); + + __max7301_set(ts, offset, value); + + mutex_unlock(&ts->lock); +} + +int __devinit __max730x_probe(struct max7301 *ts) +{ + struct device *dev = ts->dev; + struct max7301_platform_data *pdata; + int i, ret; + + pdata = dev->platform_data; + if (!pdata || !pdata->base) { + dev_err(dev, "incorrect or missing platform data\n"); + return -EINVAL; + } + + mutex_init(&ts->lock); + dev_set_drvdata(dev, ts); + + /* Power up the chip and disable IRQ output */ + ts->write(dev, 0x04, 0x01); + + ts->chip.label = dev->driver->name; + + ts->chip.direction_input = max7301_direction_input; + ts->chip.get = max7301_get; + ts->chip.direction_output = max7301_direction_output; + ts->chip.set = max7301_set; + + ts->chip.base = pdata->base; + ts->chip.ngpio = PIN_NUMBER; + ts->chip.can_sleep = 1; + ts->chip.dev = dev; + ts->chip.owner = THIS_MODULE; + + /* + * tristate all pins in hardware and cache the + * register values for later use. + */ + for (i = 1; i < 8; i++) { + int j; + /* 0xAA means input with internal pullup disabled */ + ts->write(dev, 0x08 + i, 0xAA); + ts->port_config[i] = 0xAA; + for (j = 0; j < 4; j++) { + int offset = (i - 1) * 4 + j; + ret = max7301_direction_input(&ts->chip, offset); + if (ret) + goto exit_destroy; + } + } + + ret = gpiochip_add(&ts->chip); + if (ret) + goto exit_destroy; + + return ret; + +exit_destroy: + dev_set_drvdata(dev, NULL); + mutex_destroy(&ts->lock); + return ret; +} +EXPORT_SYMBOL_GPL(__max730x_probe); + +int __devexit __max730x_remove(struct device *dev) +{ + struct max7301 *ts = dev_get_drvdata(dev); + int ret; + + if (ts == NULL) + return -ENODEV; + + dev_set_drvdata(dev, NULL); + + /* Power down the chip and disable IRQ output */ + ts->write(dev, 0x04, 0x00); + + ret = gpiochip_remove(&ts->chip); + if (!ret) { + mutex_destroy(&ts->lock); + kfree(ts); + } else + dev_err(dev, "Failed to remove GPIO controller: %d\n", ret); + + return ret; +} +EXPORT_SYMBOL_GPL(__max730x_remove); diff --git a/include/linux/spi/max7301.h b/include/linux/spi/max7301.h index 6dfd83f19b4b..34af0a3477bf 100644 --- a/include/linux/spi/max7301.h +++ b/include/linux/spi/max7301.h @@ -1,9 +1,27 @@ #ifndef LINUX_SPI_MAX7301_H #define LINUX_SPI_MAX7301_H +#include + +/* + * Some registers must be read back to modify. + * To save time we cache them here in memory + */ +struct max7301 { + struct mutex lock; + u8 port_config[8]; /* field 0 is unused */ + u32 out_level; /* cached output levels */ + struct gpio_chip chip; + struct device *dev; + int (*write)(struct device *dev, unsigned int reg, unsigned int val); + int (*read)(struct device *dev, unsigned int reg); +}; + struct max7301_platform_data { /* number assigned to the first GPIO */ unsigned base; }; +extern int __max730x_remove(struct device *dev); +extern int __max730x_probe(struct max7301 *ts); #endif -- 2.20.1