pca9698_gpio.rar_PCA9698_pca9698.c

/* * 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] = i2cd