From: Balaji Venkatachalam <balaji.v@xxxxxxxxxxxx>
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 <balaji.v@xxxxxxxxxxxx>
---
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 <balaji.v@xxxxxxxxxxxx>
+ * based on pca953x.c written by eric miao <eric.miao@xxxxxxxxxxx>
+ *
+ * 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;
+};
--
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