Add the MAX7300-I2C variant to the MAX7301-SPI version. They share most parts of the driver (i.e. the logic) and the read/write-register functions get encapsulated. It is thus possible to use both variants simultaneously.
Signed-off-by: Wolfram Sang <[email protected]> Cc: Juergen Beisert <[email protected]> Cc: David Brownell <[email protected]> Cc: Jean Delvare <[email protected]> Cc: Andrew Morton <[email protected]> --- drivers/gpio/Kconfig | 24 +++- drivers/gpio/max7301.c | 274 +++++++++++++++++++++++++++++++----------------- 2 files changed, 197 insertions(+), 101 deletions(-) diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig index 2ad0128..a1d2608 100644 --- a/drivers/gpio/Kconfig +++ b/drivers/gpio/Kconfig @@ -65,6 +65,24 @@ config GPIO_SYSFS # put expanders in the right section, in alphabetical order +comment "GPIO expanders for multiple busses" + +config GPIO_MAX7301 + tristate "Maxim MAX730x GPIO expander" + help + GPIO driver for Maxim MAX7300/7301 GPIO expanders. + Also select which bus you want to use. + +if GPIO_MAX7301 +config GPIO_MAX7301_I2C + bool "I2C support (for MAX7300)" + depends on I2C + +config GPIO_MAX7301_SPI + bool "SPI support (for MAX7301)" + depends on SPI_MASTER +endif + comment "Memory mapped GPIO expanders:" config GPIO_PL061 @@ -198,12 +216,6 @@ config GPIO_LANGWELL comment "SPI GPIO expanders:" -config GPIO_MAX7301 - tristate "Maxim MAX7301 GPIO expander" - depends on SPI_MASTER - help - gpio driver for Maxim MAX7301 SPI GPIO expander. - config GPIO_MCP23S08 tristate "Microchip MCP23S08 I/O expander" depends on SPI_MASTER diff --git a/drivers/gpio/max7301.c b/drivers/gpio/max7301.c index 480956f..4ac5175 100644 --- a/drivers/gpio/max7301.c +++ b/drivers/gpio/max7301.c @@ -3,6 +3,7 @@ * * 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 @@ -34,12 +35,11 @@ #include <linux/init.h> #include <linux/platform_device.h> #include <linux/mutex.h> +#include <linux/i2c.h> #include <linux/spi/spi.h> #include <linux/spi/max7301.h> #include <linux/gpio.h> -#define DRIVER_NAME "max7301" - /* * Pin configurations, see MAX7301 datasheet page 6 */ @@ -60,62 +60,21 @@ struct max7301 { u8 port_config[8]; /* field 0 is unused */ u32 out_level; /* cached output levels */ struct gpio_chip chip; - struct spi_device *spi; + struct device *dev; + int (*write)(struct device *dev, unsigned int reg, unsigned int val); + int (*read)(struct device *dev, unsigned int reg); }; -/** - * 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) -{ - 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) -{ - int ret; - u16 word; - - word = 0x8000 | (reg << 8); - ret = spi_write(spi, (const u8 *)&word, sizeof(word)); - if (ret) - return ret; - /* - * This relies on the fact, that a transfer with NULL tx_buf shifts out - * zero bytes (=NOOP for MAX7301) - */ - ret = spi_read(spi, (u8 *)&word, sizeof(word)); - if (ret) - return ret; - 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; + 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]; @@ -123,9 +82,9 @@ static int max7301_direction_input(struct gpio_chip *chip, unsigned offset) /* 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)); + *config = (*config & ~(3 << offset_bits)) | (2 << offset_bits); - ret = max7301_write(ts->spi, 0x08 + (offset >> 2), *config); + ret = ts->write(ts->dev, 0x08 + (offset >> 2), *config); mutex_unlock(&ts->lock); @@ -136,10 +95,10 @@ 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); + return ts->write(ts->dev, 0x20 + offset, 0x01); } else { ts->out_level &= ~(1 << offset); - return max7301_write(ts->spi, 0x20 + offset, 0x00); + return ts->write(ts->dev, 0x20 + offset, 0x00); } } @@ -148,21 +107,23 @@ static int max7301_direction_output(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); - *config = (*config & ~(3 << (offset & 3))) | (1 << (offset & 3)); + *config = (*config & ~(3 << offset_bits)) | (1 << offset_bits); ret = __max7301_set(ts, offset, value); if (!ret) - ret = max7301_write(ts->spi, 0x08 + (offset >> 2), *config); + ret = ts->write(ts->dev, 0x08 + (offset >> 2), *config); mutex_unlock(&ts->lock); @@ -189,7 +150,7 @@ static int max7301_get(struct gpio_chip *chip, unsigned offset) case 2: case 3: /* Input: read out */ - level = max7301_read(ts->spi, 0x20 + offset) & 0x01; + level = ts->read(ts->dev, 0x20 + offset) & 0x01; } mutex_unlock(&ts->lock); @@ -210,41 +171,25 @@ static void max7301_set(struct gpio_chip *chip, unsigned offset, int value) mutex_unlock(&ts->lock); } -static int __devinit max7301_probe(struct spi_device *spi) +static int __devinit __max7301_probe(struct max7301 *ts) { - struct max7301 *ts; + struct device *dev = ts->dev; struct max7301_platform_data *pdata; int i, ret; - pdata = spi->dev.platform_data; + pdata = dev->platform_data; if (!pdata || !pdata->base) { - dev_dbg(&spi->dev, "incorrect or missing platform data\n"); + dev_err(dev, "incorrect or missing platform data\n"); return -EINVAL; } - /* - * bits_per_word cannot be configured in platform data - */ - spi->bits_per_word = 16; - - ret = spi_setup(spi); - if (ret < 0) - return ret; - - ts = kzalloc(sizeof(struct max7301), GFP_KERNEL); - if (!ts) - return -ENOMEM; - mutex_init(&ts->lock); - - dev_set_drvdata(&spi->dev, ts); + dev_set_drvdata(dev, ts); /* Power up the chip and disable IRQ output */ - max7301_write(spi, 0x04, 0x01); - - ts->spi = spi; + ts->write(dev, 0x04, 0x01); - ts->chip.label = DRIVER_NAME, + ts->chip.label = dev->driver->name; ts->chip.direction_input = max7301_direction_input; ts->chip.get = max7301_get; @@ -254,7 +199,7 @@ static int __devinit max7301_probe(struct spi_device *spi) ts->chip.base = pdata->base; ts->chip.ngpio = PIN_NUMBER; ts->chip.can_sleep = 1; - ts->chip.dev = &spi->dev; + ts->chip.dev = dev; ts->chip.owner = THIS_MODULE; /* @@ -264,7 +209,7 @@ static int __devinit max7301_probe(struct spi_device *spi) for (i = 1; i < 8; i++) { int j; /* 0xAA means input with internal pullup disabled */ - max7301_write(spi, 0x08 + i, 0xAA); + ts->write(dev, 0x08 + i, 0xAA); ts->port_config[i] = 0xAA; for (j = 0; j < 4; j++) { int offset = (i - 1) * 4 + j; @@ -281,49 +226,188 @@ static int __devinit max7301_probe(struct spi_device *spi) return ret; exit_destroy: - dev_set_drvdata(&spi->dev, NULL); + dev_set_drvdata(dev, NULL); mutex_destroy(&ts->lock); - kfree(ts); return ret; } -static int __devexit max7301_remove(struct spi_device *spi) +static int __devexit __max7301_remove(struct device *dev) { - struct max7301 *ts; + struct max7301 *ts = dev_get_drvdata(dev); int ret; - ts = dev_get_drvdata(&spi->dev); if (ts == NULL) return -ENODEV; - dev_set_drvdata(&spi->dev, NULL); + dev_set_drvdata(dev, NULL); /* Power down the chip and disable IRQ output */ - max7301_write(spi, 0x04, 0x00); + ts->write(dev, 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); + dev_err(dev, "Failed to remove GPIO controller: %d\n", ret); return ret; } +#ifdef CONFIG_GPIO_MAX7301_SPI + +/* 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)); +} + +/* 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)); + if (ret) + return ret; + /* + * This relies on the fact, that a transfer with NULL tx_buf shifts out + * zero bytes (=NOOP for MAX7301) + */ + ret = spi_read(spi, (u8 *)&word, sizeof(word)); + if (ret) + return ret; + return word & 0xff; +} + +static int __devinit max7301_probe(struct spi_device *spi) +{ + struct max7301 *ts; + int ret; + + /* bits_per_word cannot be configured in platform data */ + spi->bits_per_word = 16; + ret = spi_setup(spi); + if (ret < 0) + return ret; + + ts = kzalloc(sizeof(struct max7301), GFP_KERNEL); + if (!ts) + return -ENOMEM; + + ts->read = max7301_spi_read; + ts->write = max7301_spi_write; + ts->dev = &spi->dev; + + ret = __max7301_probe(ts); + if (ret) + kfree(ts); + return ret; +} + +static int __devexit max7301_remove(struct spi_device *spi) +{ + return __max7301_remove(&spi->dev); +} + static struct spi_driver max7301_driver = { .driver = { - .name = DRIVER_NAME, + .name = "max7301", .owner = THIS_MODULE, }, .probe = max7301_probe, .remove = __devexit_p(max7301_remove), }; +MODULE_ALIAS("spi:max7301"); + +#define max7301_add_driver(drv) spi_register_driver(drv) +#define max7301_del_driver(drv) spi_unregister_driver(drv) +#else +#define max7301_add_driver(drv) (0) +#define max7301_del_driver(drv) do { } while(0) +#endif /* CONFIG_GPIO_MAX7301_SPI */ + +#ifdef CONFIG_GPIO_MAX7301_I2C + +static int max7301_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 max7301_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 = max7301_i2c_read; + ts->write = max7301_i2c_write; + ts->dev = &client->dev; + + ret = __max7301_probe(ts); + if (ret) + kfree(ts); + return ret; +} + +static int __devexit max7300_remove(struct i2c_client *client) +{ + return __max7301_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, +}; + +#define max7300_add_driver(drv) i2c_add_driver(drv) +#define max7300_del_driver(drv) i2c_del_driver(drv) +#else +#define max7300_add_driver(drv) (0) +#define max7300_del_driver(drv) do { } while(0) +#endif /* CONFIG_GPIO_MAX7301_I2C */ + static int __init max7301_init(void) { - return spi_register_driver(&max7301_driver); + int ret; + ret = max7300_add_driver(&max7300_driver); + if (ret) + return ret; + ret = max7301_add_driver(&max7301_driver); + return ret; } /* register after spi postcore initcall and before * subsys initcalls that may rely on these GPIOs @@ -332,11 +416,11 @@ subsys_initcall(max7301_init); static void __exit max7301_exit(void) { - spi_unregister_driver(&max7301_driver); + max7300_del_driver(&max7300_driver); + max7301_del_driver(&max7301_driver); } 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("MAX7300/1 based GPIO-Expander"); -- 1.6.3.3 -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
