/* Copyright (c) 2010, Code Aurora Forum. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
* only version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*/
#include <linux/gpio.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/slab.h>
#include <linux/workqueue.h>
#include <linux/i2c/sx150x.h>
#define NO_UPDATE_PENDING -1
struct sx150x_device_data {
u8 reg_pullup;
u8 reg_pulldn;
u8 reg_drain;
u8 reg_polarity;
u8 reg_dir;
u8 reg_data;
u8 reg_irq_mask;
u8 reg_irq_src;
u8 reg_sense;
u8 reg_clock;
u8 reg_misc;
u8 reg_reset;
u8 ngpios;
};
struct sx150x_chip {
struct gpio_chip gpio_chip;
struct i2c_client *client;
const struct sx150x_device_data *dev_cfg;
int irq_summary;
int irq_base;
int irq_update;
u32 irq_sense;
u32 irq_masked;
u32 dev_sense;
u32 dev_masked;
struct irq_chip irq_chip;
struct mutex lock;
};
static const struct sx150x_device_data sx150x_devices[] = {
[0] = { /* sx1508q */
.reg_pullup = 0x03,
.reg_pulldn = 0x04,
.reg_drain = 0x05,
.reg_polarity = 0x06,
.reg_dir = 0x07,
.reg_data = 0x08,
.reg_irq_mask = 0x09,
.reg_irq_src = 0x0c,
.reg_sense = 0x0b,
.reg_clock = 0x0f,
.reg_misc = 0x10,
.reg_reset = 0x7d,
.ngpios = 8
},
[1] = { /* sx1509q */
.reg_pullup = 0x07,
.reg_pulldn = 0x09,
.reg_drain = 0x0b,
.reg_polarity = 0x0d,
.reg_dir = 0x0f,
.reg_data = 0x11,
.reg_irq_mask = 0x13,
.reg_irq_src = 0x19,
.reg_sense = 0x17,
.reg_clock = 0x1e,
.reg_misc = 0x1f,
.reg_reset = 0x7d,
.ngpios = 16
},
};
static const struct i2c_device_id sx150x_id[] = {
{"sx1508q", 0},
{"sx1509q", 1},
{}
};
MODULE_DEVICE_TABLE(i2c, sx150x_id);
static s32 sx150x_i2c_write(struct i2c_client *client, u8 reg, u8 val)
{
s32 err = i2c_smbus_write_byte_data(client, reg, val);
if (err < 0)
dev_warn(&client->dev,
"i2c write fail: can't write %02x to %02x: %d\n",
val, reg, err);
return err;
}
static s32 sx150x_i2c_read(struct i2c_client *client, u8 reg, u8 *val)
{
s32 err = i2c_smbus_read_byte_data(client, reg);
if (err >= 0)
*val = err;
else
dev_warn(&client->dev,
"i2c read fail: can't read from %02x: %d\n",
reg, err);
return err;
}
static inline bool offset_is_oscio(struct sx150x_chip *chip, unsigned offset)
{
return (chip->dev_cfg->ngpios == offset);
}
/*
* These utility functions solve the common problem of locating and setting
* configuration bits. Configuration bits are grouped into registers
* whose indexes increase downwards. For example, with eight-bit registers,
* sixteen gpios would have their config bits grouped in the following order:
* REGISTER N-1 [ f e d c b a 9 8 ]
* N [ 7 6 5 4 3 2 1 0 ]
*
* For multi-bit configurations, the pattern gets wider:
* REGISTER N-3 [ f f e e d d c c ]
* N-2 [ b b a a 9 9 8 8 ]
* N-1 [ 7 7 6 6 5 5 4 4 ]
* N [ 3 3 2 2 1 1 0 0 ]
*
* Given the address of the starting register 'N', the index of the gpio
* whose configuration we seek to change, and the width in bits of that
* configuration, these functions allow us to locate the correct
* register and mask the correct bits.
*/
static inline void sx150x_find_cfg(u8 offset, u8 width,
u8 *reg, u8 *mask, u8 *shift)
{
*reg -= offset * width / 8;
*mask = (1 << width) - 1;
*shift = (offset * width) % 8;
*mask <<= *shift;
}
static s32 sx150x_write_cfg(struct sx150x_chip *chip,
u8 offset, u8 width, u8 reg, u8 val)
{
u8 mask;
u8 data;
u8 shift;
s32 err;
sx150x_find_cfg(offset, width, ®, &mask, &shift);
err = sx150x_i2c_read(chip->client, reg, &data);
if (err < 0)
return err;
data &= ~mask;
data |= (val << shift) & mask;
return sx150x_i2c_write(chip->client, reg, data);
}
static int sx150x_get_io(struct sx150x_chip *chip, unsigned offset)
{
u8 reg = chip->dev_cfg->reg_data;
u8 mask;
u8 data;
u8 shift;
s32 err;
sx150x_find_cfg(offset, 1, ®, &mask, &shift);
err = sx150x_i2c_read(chip->client, reg, &data);
if (err >= 0)
err = (data & mask) != 0 ? 1 : 0;
return err;
}
static void sx150x_set_oscio(struct sx150x_chip *chip, int val)
{
sx150x_i2c_write(chip->client,
chip->dev_cfg->reg_clock,
(val ? 0x1f : 0x10));
}
static void sx150x_set_io(struct sx150x_chip *chip, unsigned offset, int val)
{
sx150x_write_cfg(chip,
offset,
1,
chip->dev_cfg->reg_data,
(val ? 1 : 0));
}
static int sx150x_io_input(struct sx150x_chip *chip, unsigned offset)
{
return sx150x_write_cfg(chip,
offset,
1,
chip->dev_cfg->reg_dir,
1);
}
static int sx150x_io_output(struct sx150x_chip *chip, unsigned offset, int val)
{
int err;
err = sx150x_write_cfg(chip,
offset,
1,
chip->dev_cfg->reg_data,
(val ? 1 : 0));
if (err >= 0)
err = sx150x_write_cfg(chip,
offset,
1,
chip->dev_cfg->reg_dir,
0);
return err;
}
static int sx150x_gpio_get(struct gpio_chip *gc, unsigned offset)
{
struct sx150x_chip *chip;
int status = -EINVAL;
chip = container_of(gc, struct sx150x_chip, gpio_chip);
if (!offset_is_oscio(chip, offset)) {
mutex_lock(&chip->lock);
status = sx150x_get_io(chip, offset);
mutex_unlock(&chip->lock);
}
return status;
}
static void sx150x_gpio_set(struct gpio_chip *gc, unsigned offset, int val)
{
struct sx150x_chip *chip;
chip = container_of(gc, struct sx150x_chip, gpio_chip);
mutex_lock(&chip->lock);
if (offset_is_oscio(chip, offset))
sx150x_set_oscio(chip, val);
else
sx150x_set_io(chip, offset, val);
mutex_unlock(&chip->lock);
}
static int sx150x_gpio_direction_input(struct gpio_chip *gc, unsigned offset)
{
struct sx150x_chip *chip;
int status = -EINVAL;
chip = container_of(gc, struct sx150x_chip, gpio_chip);
if (!offset_is_oscio(chip, offset)) {
mutex_lock(&chip->lock);
status = sx150x_io_input(chip, offset);
mutex_unlock(&chip->lock);
}
return status;
}
static int sx150x_gpio_direction_output(struct gpio_chip *gc,
unsigned offset,
int val)
{
struct sx150x_chip *chip;
int status = 0;
chip = container_of(gc, struct sx150x_chip, gpio_chip);
if (!offset_is_oscio(chip, offset)) {
mutex_lock(&chip->lock);
status = sx150x_io_output(chip, offset, val);
mutex_unlock(&chip->lock);
}
return status;
}
static int sx150x_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
{
struct sx150x_chip *chip;
chip = container_of(gc, struct sx150x_chip, gpio_chip);
if (offset >= chip->dev_cfg->ngpios)
return -EINVAL;
if (chip->irq_base < 0)
return -EINVAL;
return chip->irq_base + offset;
}
static void sx150x_irq_mask(struct irq_data *d)
{
struct sx150x_chip *chip = irq_data_get_irq_chip_data(d);
unsigned n;
n = d->irq - chip->irq_base;
chip->irq_masked |= (1 << n);
chip->irq_update = n;
}
static void sx150x_irq_unmask(struct irq_data *d)
{
struct sx150x_chip *chip = irq_data_get_irq_chip_data(d);
unsigned n;
n = d->irq - chip->irq_base;
chip->irq_masked &= ~(1 << n);
chip->irq_update = n;
}
static int sx150x_irq_set_type(struct irq_data *d, unsigned int flow_type)
{
struct sx150x_chip *chip = irq_data_get_irq_chip_data(d);
unsigned n, val = 0;
if (flow_type & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW))
return -EINVAL;
n = d->irq - chip->irq_base;
if (flow_type & IRQ_TYPE_EDGE_RISING)
val |= 0x1;
if (flow_type & IRQ_TYPE_EDGE_FALLING)
val |= 0x2;
chip->irq_sense &= ~(3UL << (n * 2));
chip->irq_sense |= val << (n * 2);
chip->irq_update = n;
return 0;
}
static irqreturn_t sx150x_irq_thread_fn(int irq, void *dev_id)
{
struct sx150x_chip *chip = (struct sx150x_chip *)dev_id;
unsigned nhandled = 0;
unsigned sub_irq;
unsigned n;
s32 err;
u8 val;
int i;
for (i = (chip->dev_cfg->ngpios / 8) - 1; i >= 0; --i) {
err = sx150x_i2c_read(chip->client,
chip->dev_cfg->reg_irq_src - i,
&val);
if (err < 0)
continue;
sx150x_i2c_write(chip->client,
chip->dev_cfg->reg_irq_src - i,
val);
for (n = 0; n < 8; ++n) {
if (val & (1 << n)) {
sub_irq = chip->irq_base + (i * 8) + n;
handle_nested_irq(sub_irq);
++nhandled;
}
}
}
return (nhandled > 0 ? IRQ_HANDLED : IRQ_NONE);
}
static void sx150x_irq_bus_lock(struct irq_data *d)
{
struct sx150x_chip *chip = irq_data_get_irq_chip_data(d);
mutex_lock(&chip->lock);
}
static void sx150x_irq_bus_sync_unlock(struct irq_data *d)
{
struct sx150x_chip *chip = irq_data_get_irq_chip_data(d);
unsigned n;
if (chip->irq_update == NO_UPDATE_PENDING)
goto out;
n = chip->irq_update;
chip->irq_update = NO_UPDATE_PENDING;
/* Avoid updates if nothing changed */
if (chip->dev_sense == chip->irq_sense &&
chip->dev_sense == chip->irq_masked)
goto out;
chip->dev_sense = chip->irq_sense;
chip->dev_masked = chip->irq_masked;
if (chip->irq_masked & (1 << n)) {
sx150x_write_cfg(chip, n, 1, chip->dev_cfg->reg_irq_mask, 1);
sx150x_write_cfg(chip, n, 2, chip->dev_cfg->reg_sense, 0);
} else {
sx150x_write_cfg(chip, n, 1, chip->dev_cfg->reg_irq_mask, 0);
sx150x_write_cfg(chip, n, 2, chip->dev_cfg->reg_sense,
chip->irq_sense >> (n * 2));
}
out:
mutex_unlock(&chip->lock);
}
static void sx150x_init_chip(struct sx150x_chip *chip,
struct i2c_client *client,
kernel_ulong_t driver_data,
struct sx150x_platform_data *pdata)
{
mutex_init(&chip->lock);
chip->client = client;
chip->dev_cfg = &sx150x_devices[driver_data];
chip->gpio_chip.label = client->name;
chip->gpio_chip.direction_input = sx150x_gpio_direction_input;
chip->gpio_chip.direction_output = sx150x_gpio_direction_output;
chip->gpio_chip.get = sx150x_gpio_get;
chip->gpio_chip.set = sx150x_gpio_set;
chip->gpio_chip.to_irq = sx150x_gpio_to_irq;
chip->gpio_chip.base = pdata->gpio_base;
chip->gpio_chip.can_sleep = 1;
chip->gpio_chip.ngpio = chip->dev_cfg->ngpios;
if (pdata->oscio_is_gpo)
++chip->gpio_chip.ngpio;
chip->irq_chip.name = client->name;
chip->irq_chip.irq_mask = sx150x_irq_mask;
chip->irq_chip.irq_unmask = sx150x_irq_unmask;
chip->irq_chip.irq_set_type = sx150x_irq_set_type;
chip->irq_chip.irq_bus_lock = sx150x_irq_bus_lock;
chip->irq_chip.irq_bus_sync_unlock = sx150x_irq_bus_sync_unlock;
chip->irq_summary = -1;
chip->irq_base = -1;
chip->irq_masked = ~0;
chip->irq_sense = 0;
chip->dev_masked = ~0;
chip->dev_sense = 0;
chip->irq_update = NO_UPDATE_PENDING;
}
static int sx150x_init_io(struct sx150x_chip *chip, u8 base, u16 cfg)
{
int err = 0;
unsigned n;
for (n = 0; err >= 0 && n < (chip->dev_cfg->ngpios / 8); ++n)
err = sx150x_i2c_write(chip->client, base - n, cfg >> (n * 8));
return err;
}
static int sx150x_reset(struct sx150x_chip *chip)
{
int err;
err = i2c_smbus_write_byte_data(chip->client,
chip->dev_cfg->reg_reset,
0x12);
if (err < 0)
return err;
err = i2c_smbus_write_byte_data(chip->client,
chip->dev_cfg->reg_reset,
0x34);
return err;
}
static int sx150x_init_hw(struct sx150x_chip *chip,
struct sx150x_platform_data *pdata)
{
int err = 0;
if (pdata->reset_during_probe) {
err = sx150x_reset(chip);
if (err < 0)
return err;
}
err = sx150x_i2c_write(chip->client,
chip->dev_cfg->reg_misc,
0x01);
if (err < 0)
return err;
err = sx150x_init_io(chip, chip->dev_cfg->reg_pullup,
pdata->io_pullup_ena);
if (err < 0)
return err;
err = sx150x_init_io(chip, chip->dev_cfg->reg_pulldn,
pdata->io_pulldn_ena);
if (err < 0)
return err;
err = sx150x_init_io(chip, chip->dev_cfg->reg_drain,
pdata->io_open_drain_ena);
if (err < 0)
return err;
err = sx150x_init_io(chip, chip->dev_cfg->reg_polarity,
pdata->io_polarity);
if (err < 0)
return err;
if (pdata->oscio_is_gpo)
sx150x_set_oscio(chip, 0);
return err;
}
static int sx150x_install_irq_chip(struct sx150x_chip *chip,
int irq_summary,
int irq_base)
{
int err;
unsigned n;
unsigned irq;
chip->irq_summary = irq_summary;
chip->irq_base = irq_base;
for (n = 0; n < chip->dev_cfg->ngpios; ++n) {
irq = irq_base + n;
irq_set_chip_data(irq, chip);
irq_set_chip_and_handler(irq, &chip->irq_chip, handle_edge_irq);
irq_set_nested_thread(irq, 1);
#ifdef CONFIG_ARM
set_irq_flags(irq, IRQF_VALID);
#else
irq_set_noprobe(irq);
#endif
}
err = request_threaded_irq(irq_summary,
NULL,
sx150x_irq_thread_fn,
IRQF_SHARED | IRQF_TRIGGER_FALLING,
chip->irq_chip.name,
chip);
if (err < 0) {
chip->irq_summary = -1;
chip->irq_base = -1;
}
return err;
}
static void sx150x_remove_irq_chip(struct sx150x_chip *chip)
{
unsigned n;
unsigned irq;
free_irq(chip->irq_summary, chip);
for (n = 0; n < chip->dev_cfg->ngpios; ++n) {
irq = chip->irq_base + n;
irq_set_chip_and_handler(irq, NULL, NULL);
}
}
static int sx150x_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
static const u32 i2c_funcs = I2C_FUNC_SMBUS_BYTE_DATA |
I2C_FUNC_SMBUS_WRITE_WORD_DATA;
struct sx150x_platform_data *pdata;
struct sx150x_chip *chip;
int rc;
pdata = client->dev.platform_data;
if (!pdata)
return -EINVAL;
if (!i2c_check_functionality(client->adapter, i2c_funcs))
return -ENOSYS;
chip = kzalloc(sizeof(struct sx150x_chip), GFP_KERNEL);
if (!chip)
return -ENOMEM;
sx150x_init_chip(chip, client, id->driver_data, pdata);
rc = sx150x_init_hw(chip, pdata);
if (rc < 0)
goto probe_fail_pre_gpiochip_add;
rc = gpiochip_add(&chip->gpio_chip);
if (rc < 0)
goto probe_fail_pre_gpiochip_add;
if (pdata->irq_summary >= 0) {
rc = sx150x_install_irq_chip(chip,
pdata->irq_summary,
pdata->irq_base);
if (rc < 0)
goto probe_fail_post_gpiochip_add;
}
i2c_set_clientdata(client, chip);
return 0;
probe_fail_post_gpiochip_add:
WARN_ON(gpiochip_remove(&chip->gpio_chip) < 0);
probe_fail_pre_gpiochip_add:
kfree(chip);
return rc;
}
static int sx150x_remove(struct i2c_client *client)
{
struct sx150x_chip *chip;
int rc;
chip = i2c_get_clientdata(client);
rc = gpiochip_remove(&chip->gpio_chip);
if (rc < 0)
return rc;
if (chip->irq_summary >= 0)
sx150x_remove_irq_chip(chip);
kfree(chip);
return 0;
}
static struct i2c_driver sx150x_driver = {
.driver = {
.name = "sx150x",
.owner = THIS_MODULE
},
.probe = sx150x_probe,
.remove = sx150x_remove,
.id_table = sx150x_id,
};
static int __init sx150x_init(void)
{
return i2c_add_driver(&sx150x_driver);
}
subsys_initcall(sx150x_init);
static void __exit sx150x_exit(void)
{
return i2c_del_driver(&sx150x_driver);
}
module_exit(sx150x_exit);
MODULE_AUTHOR("Gregory Bean <gbean@codeaurora.org>");
MODULE_DESCRIPTION("Driver for Semtech SX150X I2C GPIO Expanders");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("i2c:sx150x");