From: Balaji Venkatachalam <[email protected]> Patch [V1.24] for NXP's PCA9698 GPIO Expander controlled via I2C (@ 100KHz). I tested it on my custom board with ARM9 (Freescale i.MX233) with Kernel 2.6.31.14.
Todo List: 1. Test enabling the CONFIG_OF_GPIO 2. Arrive at strategy to implement GPIO All Call Command via sys interface Any comments are welcome. Signed-off-by: Balaji Venkatachalam <[email protected]> --- diff -uprN -X a/Documentation/dontdiff a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig --- a/drivers/gpio/Kconfig 2010-07-05 22:41:43.000000000 +0530 +++ b/drivers/gpio/Kconfig 2011-02-20 20:07:09.000000000 +0530 @@ -124,6 +124,18 @@ config GPIO_PCA953X This driver can also be built as a module. If so, the module will be called pca953x. +config GPIO_PCA9698 + tristate "PCA9698 I/O ports" + depends on I2C + help + Say yes here to provide access to several register of PCA9698 + + 40 bits: pca9698 + + This driver can also be built as a module. If so, the module + will be called pca9698. + + config GPIO_PCF857X tristate "PCF857x, PCA{85,96}7x, and MAX732[89] I2C GPIO expanders" depends on I2C diff -uprN -X a/Documentation/dontdiff a/drivers/gpio/Makefile b/drivers/gpio/Makefile --- a/drivers/gpio/Makefile 2010-07-05 22:41:43.000000000 +0530 +++ b/drivers/gpio/Makefile 2011-02-20 20:07:42.000000000 +0530 @@ -8,6 +8,7 @@ obj-$(CONFIG_GPIO_MAX7301) += max7301.o obj-$(CONFIG_GPIO_MAX732X) += max732x.o obj-$(CONFIG_GPIO_MCP23S08) += mcp23s08.o obj-$(CONFIG_GPIO_PCA953X) += pca953x.o +obj-$(CONFIG_GPIO_PCA9698) += pca9698.o obj-$(CONFIG_GPIO_PCF857X) += pcf857x.o obj-$(CONFIG_GPIO_PL061) += pl061.o obj-$(CONFIG_GPIO_TWL4030) += twl4030-gpio.o diff -uprN -X a/Documentation/dontdiff a/drivers/gpio/pca9698.c b/drivers/gpio/pca9698.c --- a/drivers/gpio/pca9698.c 1970-01-01 05:30:00.000000000 +0530 +++ b/drivers/gpio/pca9698.c 2011-02-20 21:33:45.000000000 +0530 @@ -0,0 +1,401 @@ +/* + * NXP pca9698.c - 40 bit I/O Expander on I2C bus + * + * Copyright (C) 2011 Thotaka Technologies Pvt Ltd + * Author: Balaji Venkatachalam <[email protected]> + * based on pca953x.c written by eric miao <[email protected]> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + */ + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/i2c.h> +#include <linux/i2c/pca9698.h> + +#ifdef CONFIG_OF_GPIO +/*TODO: Not Tested. As it is adopted from PCA959x.c*/ +#include <linux/of_platform.h> +#include <linux/of_gpio.h> +#endif + +#include <linux/gpio.h> + +#define DRV_NAME "pca9698" + +#define PCA9698_INPUT 0 +#define PCA9698_OUTPUT 1 +#define PCA9698_INVERT 2 +#define PCA9698_DIRECTION 3 + + + +static const struct i2c_device_id pca9698_id[] = { + { "pca9698", 40, }, + { } +}; +MODULE_DEVICE_TABLE(i2c, pca9698_id); + +struct pca9698_chip { + unsigned gpio_start; + uint8_t reg_output[PCA9698_MAX_BANKS]; + uint8_t reg_direction[PCA9698_MAX_BANKS]; + struct i2c_client *client; + struct pca9698_platform_data *dyn_pdata; + struct gpio_chip gpio_chip; + char **names; +}; +uint8_t i2cdataaddr[5] = {0, 0, 0, 0, 0}; + +static int pca9698_write_reg(struct pca9698_chip *chip, int reg, uint8_t *val) +{ + int ret; + ret = i2c_smbus_write_i2c_block_data(chip->client, + ((reg << 3)|0x80), 5, val); + + if (ret < 0) { + dev_err(&chip->client->dev, "failed writing register\n"); + return ret; + } + return 0; +} + +static int pca9698_read_reg(struct pca9698_chip *chip, int reg, uint8_t *val) +{ + int ret; + ret = i2c_smbus_read_i2c_block_data(chip->client, + ((reg << 3)|0x80), 5, val); + if (ret < 0) { + dev_err(&chip->client->dev, "failed reading register\n"); + return ret; + } + return 0; +} + +static int pca9698_gpio_direction_input(struct gpio_chip *gc, unsigned off) +{ + struct pca9698_chip *chip; + int ret, bankid; + + chip = container_of(gc, struct pca9698_chip, gpio_chip); + bankid = 0; + do { + i2cdataaddr[bankid] = chip->reg_direction[bankid] | (1u << off); + } while (++bankid <= PCA9698_MAX_BANKS); + ret = pca9698_write_reg(chip, PCA9698_DIRECTION, i2cdataaddr); + if (ret) + return ret; + bankid = 0; + do { + chip->reg_direction[bankid] = i2cdataaddr[bankid]; + } while (++bankid <= PCA9698_MAX_BANKS); + + return 0; +} + +static int pca9698_gpio_direction_output(struct gpio_chip *gc, + unsigned off, int val) +{ + struct pca9698_chip *chip; + int ret, bankid = 0; + unsigned int port = 0; + chip = container_of(gc, struct pca9698_chip, gpio_chip); + + port = off/8; + off = off%8; + bankid = 0; + do { + if (bankid == port) { + if (val) + i2cdataaddr[bankid] = + chip->reg_output[bankid] | (1u << off); + else + i2cdataaddr[bankid] = + chip->reg_output[bankid] & ~(1u << off); + } else + i2cdataaddr[bankid] = chip->reg_output[bankid]; + } while (++bankid <= PCA9698_MAX_BANKS); + ret = pca9698_write_reg(chip, PCA9698_OUTPUT, i2cdataaddr); + if (ret) + return ret; + bankid = 0; + do { + chip->reg_output[bankid] = i2cdataaddr[bankid]; + } while (++bankid <= PCA9698_MAX_BANKS); + bankid = 0; + do { + if (bankid == port) + i2cdataaddr[bankid] = + chip->reg_direction[bankid] & ~(1u << off); + else + i2cdataaddr[bankid] = chip->reg_direction[bankid]; + } while (++bankid <= PCA9698_MAX_BANKS); + ret = pca9698_write_reg(chip, PCA9698_DIRECTION, i2cdataaddr); + if (ret) + return ret; + bankid = 0; + do { + chip->reg_direction[bankid] = i2cdataaddr[bankid]; + } while (++bankid <= PCA9698_MAX_BANKS); + return 0; +} + +static int pca9698_gpio_get_value(struct gpio_chip *gc, unsigned off) +{ + struct pca9698_chip *chip; + int ret; + unsigned int port = 0; + chip = container_of(gc, struct pca9698_chip, gpio_chip); + + ret = pca9698_read_reg(chip, PCA9698_INPUT, i2cdataaddr); + if (ret < 0) { + /* NOTE: diagnostic already emitted; that's all we should + * do unless gpio_*_value_cansleep() calls become different + * from their nonsleeping siblings (and report faults). + */ + return 0; + } + port = off/8; + off = off%8; + return (i2cdataaddr[port] & (1u << off)) ? 1 : 0; +} + +static void pca9698_gpio_set_value(struct gpio_chip *gc, unsigned off, int val) +{ + struct pca9698_chip *chip; + int ret, bankid = 0; + unsigned int port = 0; + chip = container_of(gc, struct pca9698_chip, gpio_chip); + port = off/8; + off = off%8; + bankid = 0; + do { + if (bankid == port) { + if (val) + i2cdataaddr[bankid] = + chip->reg_output[bankid] | (1u << off); + else + i2cdataaddr[bankid] = + chip->reg_output[bankid] & ~(1u << off); + } else { + i2cdataaddr[bankid] = chip->reg_output[bankid]; + } + } while (++bankid <= PCA9698_MAX_BANKS); + ret = pca9698_write_reg(chip, PCA9698_OUTPUT, i2cdataaddr); + if (ret) + return; + bankid = 0; + do { + chip->reg_output[bankid] = i2cdataaddr[bankid]; + } while (++bankid <= PCA9698_MAX_BANKS); +} + +static void pca9698_setup_gpio(struct pca9698_chip *chip, int gpios) +{ + struct gpio_chip *gc; + gc = &chip->gpio_chip; + + gc->direction_input = pca9698_gpio_direction_input; + gc->direction_output = pca9698_gpio_direction_output; + gc->get = pca9698_gpio_get_value; + gc->set = pca9698_gpio_set_value; + gc->can_sleep = 1; + + gc->base = chip->gpio_start; + gc->ngpio = gpios; + gc->label = chip->client->name; + gc->dev = &chip->client->dev; + gc->owner = THIS_MODULE; + gc->names = chip->names; +} + +/* + * Handlers for alternative sources of platform_data + */ +#ifdef CONFIG_OF_GPIO +/* + * TODO: To be tested. As it is adopted from PCA953x.c + */ + */ +/* + * Translate OpenFirmware node properties into platform_data + */ +static struct pca9698_platform_data * +pca9698_get_alt_pdata(struct i2c_client *client) +{ + struct pca9698_platform_data *pdata; + struct device_node *node; + const uint16_t *val; + node = dev_archdata_get_node(&client->dev.archdata); + if (node == NULL) + return NULL; + + pdata = kzalloc(sizeof(struct pca9698_platform_data), GFP_KERNEL); + if (pdata == NULL) { + dev_err(&client->dev, "Unable to allocate platform_data\n"); + return NULL; + } + + pdata->gpio_base = -1; + val = of_get_property(node, "linux,gpio-base", NULL); + if (val) { + if (*val < 0) + dev_warn(&client->dev, + "invalid gpio-base in device tree\n"); + else + pdata->gpio_base = *val; + } + + val = of_get_property(node, "polarity", NULL); + if (val) + pdata->invert = *val; + + return pdata; +} +#else +static struct pca9698_platform_data * +pca9698_get_alt_pdata(struct i2c_client *client) +{ + return NULL; +} +#endif + +static int __devinit pca9698_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct pca9698_platform_data *pdata; + + struct pca9698_chip *chip; + int ret, bankid = 0; + chip = kzalloc(sizeof(struct pca9698_chip), GFP_KERNEL); + if (chip == NULL) + return -ENOMEM; + + pdata = client->dev.platform_data; + + if (pdata == NULL) { + pdata = pca9698_get_alt_pdata(client); + /* + * Unlike normal platform_data, this is allocated + * dynamically and must be freed in the driver + */ + chip->dyn_pdata = pdata; + } + if (pdata == NULL) { + dev_dbg(&client->dev, "no platform data\n"); + ret = -EINVAL; + goto out_failed; + } + chip->client = client; + chip->gpio_start = pdata->gpio_base; + chip->names = pdata->names; + /* initialize cached registers from their original values. + * we can't share this chip with another i2c master. + */ + pca9698_setup_gpio(chip, id->driver_data); + ret = pca9698_read_reg(chip, PCA9698_OUTPUT, i2cdataaddr); + + if (ret) + goto out_failed; + + bankid = 0; + do { + chip->reg_output[bankid] = i2cdataaddr[0]; + } while (++bankid <= PCA9698_MAX_BANKS); + + ret = pca9698_read_reg(chip, PCA9698_DIRECTION, i2cdataaddr); + + if (ret) + goto out_failed; + + bankid = 0; + do { + chip->reg_direction[bankid] = i2cdataaddr[bankid]; + } while (++bankid <= PCA9698_MAX_BANKS); + + bankid = 0; + do { + i2cdataaddr[bankid] = pdata->invert[bankid]; + } while (++bankid <= PCA9698_MAX_BANKS); + /* set platform specific polarity inversion */ + ret = pca9698_write_reg(chip, PCA9698_INVERT, i2cdataaddr); + if (ret) + goto out_failed; + + ret = gpiochip_add(&chip->gpio_chip); + if (ret) + goto out_failed; + if (pdata->setup) { + ret = pdata->setup(client, chip->gpio_chip.base, + chip->gpio_chip.ngpio, pdata->context); + if (ret < 0) + dev_warn(&client->dev, "setup failed, %d\n", ret); + } + i2c_set_clientdata(client, chip); + dev_info(&client->dev, DRV_NAME " driver registered\n"); + return 0; + +out_failed: + kfree(chip->dyn_pdata); + kfree(chip); + return ret; +} + +static int pca9698_remove(struct i2c_client *client) +{ + struct pca9698_platform_data *pdata = client->dev.platform_data; + struct pca9698_chip *chip = i2c_get_clientdata(client); + int ret = 0; + if (pdata->teardown) { + ret = pdata->teardown(client, chip->gpio_chip.base, + chip->gpio_chip.ngpio, pdata->context); + if (ret < 0) { + dev_err(&client->dev, "%s failed, %d\n", + "teardown", ret); + return ret; + } + } + + ret = gpiochip_remove(&chip->gpio_chip); + if (ret) { + dev_err(&client->dev, "%s failed, %d\n", + "gpiochip_remove()", ret); + return ret; + } + + kfree(chip->dyn_pdata); + kfree(chip); + return 0; +} + +static struct i2c_driver pca9698_driver = { + .driver = { + .name = DRV_NAME, + }, + .probe = pca9698_probe, + .remove = pca9698_remove, + .id_table = pca9698_id, +}; + +static int __init pca9698_init(void) +{ + return i2c_add_driver(&pca9698_driver); +} +/* register after i2c postcore initcall and before + * subsys initcalls that may rely on these GPIOs + */ +subsys_initcall(pca9698_init); + +static void __exit pca9698_exit(void) +{ + i2c_del_driver(&pca9698_driver); +} +module_exit(pca9698_exit); + +MODULE_AUTHOR("Balaji Venkatachalam <balaji.v@thotakaa>"); +MODULE_DESCRIPTION("GPIO expander driver for PCA9698"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("i2c:" DRV_NAME); diff -uprN -X a/Documentation/dontdiff a/include/linux/i2c/pca9698.h b/include/linux/i2c/pca9698.h --- a/include/linux/i2c/pca9698.h 1970-01-01 05:30:00.000000000 +0530 +++ b/include/linux/i2c/pca9698.h 2011-02-20 19:10:38.000000000 +0530 @@ -0,0 +1,19 @@ +/* platform data for the PCA9698 16-bit I/O expander driver */ +#define PCA9698_MAX_BANKS 5 +struct pca9698_platform_data { + /* number of the first GPIO */ + unsigned gpio_base; + + /* initial polarity inversion setting */ + uint8_t invert[PCA9698_MAX_BANKS]; + + void *context; /* param to setup/teardown */ + + int (*setup)(struct i2c_client *client, + unsigned gpio, unsigned ngpio, + void *context); + int (*teardown)(struct i2c_client *client, + unsigned gpio, unsigned ngpio, + void *context); + char **names; +}; -- 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
