/*
* Driver for ISSI IS31FL32xx family of I2C LED controllers
*
* Copyright 2015 Allworx Corp.
*
*
* 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
* published by the Free Software Foundation.
*
* Datasheets:
* http://www.issi.com/US/product-analog-fxled-driver.shtml
* http://www.si-en.com/product.asp?parentid=890
*/
#include <linux/device.h>
#include <linux/i2c.h>
#include <linux/kernel.h>
#include <linux/leds.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
/* Used to indicate a device has no such register */
#define IS31FL32XX_REG_NONE 0xFF
/* Software Shutdown bit in Shutdown Register */
#define IS31FL32XX_SHUTDOWN_SSD_ENABLE 0
#define IS31FL32XX_SHUTDOWN_SSD_DISABLE BIT(0)
/* IS31FL3216 has a number of unique registers */
#define IS31FL3216_CONFIG_REG 0x00
#define IS31FL3216_LIGHTING_EFFECT_REG 0x03
#define IS31FL3216_CHANNEL_CONFIG_REG 0x04
/* Software Shutdown bit in 3216 Config Register */
#define IS31FL3216_CONFIG_SSD_ENABLE BIT(7)
#define IS31FL3216_CONFIG_SSD_DISABLE 0
struct is31fl32xx_priv;
struct is31fl32xx_led_data {
struct led_classdev cdev;
u8 channel; /* 1-based, max priv->cdef->channels */
struct is31fl32xx_priv *priv;
};
struct is31fl32xx_priv {
const struct is31fl32xx_chipdef *cdef;
struct i2c_client *client;
unsigned int num_leds;
struct is31fl32xx_led_data leds[0];
};
/**
* struct is31fl32xx_chipdef - chip-specific attributes
* @channels : Number of LED channels
* @shutdown_reg : address of Shutdown register (optional)
* @pwm_update_reg : address of PWM Update register
* @global_control_reg : address of Global Control register (optional)
* @reset_reg : address of Reset register (optional)
* @pwm_register_base : address of first PWM register
* @pwm_registers_reversed: : true if PWM registers count down instead of up
* @led_control_register_base : address of first LED control register (optional)
* @enable_bits_per_led_control_register: number of LEDs enable bits in each
* @reset_func: : pointer to reset function
*
* For all optional register addresses, the sentinel value %IS31FL32XX_REG_NONE
* indicates that this chip has no such register.
*
* If non-NULL, @reset_func will be called during probing to set all
* necessary registers to a known initialization state. This is needed
* for chips that do not have a @reset_reg.
*
* @enable_bits_per_led_control_register must be >=1 if
* @led_control_register_base != %IS31FL32XX_REG_NONE.
*/
struct is31fl32xx_chipdef {
u8 channels;
u8 shutdown_reg;
u8 pwm_update_reg;
u8 global_control_reg;
u8 reset_reg;
u8 pwm_register_base;
bool pwm_registers_reversed;
u8 led_control_register_base;
u8 enable_bits_per_led_control_register;
int (*reset_func)(struct is31fl32xx_priv *priv);
int (*sw_shutdown_func)(struct is31fl32xx_priv *priv, bool enable);
};
static const struct is31fl32xx_chipdef is31fl3236_cdef = {
.channels = 36,
.shutdown_reg = 0x00,
.pwm_update_reg = 0x25,
.global_control_reg = 0x4a,
.reset_reg = 0x4f,
.pwm_register_base = 0x01,
.led_control_register_base = 0x26,
.enable_bits_per_led_control_register = 1,
};
static const struct is31fl32xx_chipdef is31fl3235_cdef = {
.channels = 28,
.shutdown_reg = 0x00,
.pwm_update_reg = 0x25,
.global_control_reg = 0x4a,
.reset_reg = 0x4f,
.pwm_register_base = 0x05,
.led_control_register_base = 0x2a,
.enable_bits_per_led_control_register = 1,
};
static const struct is31fl32xx_chipdef is31fl3218_cdef = {
.channels = 18,
.shutdown_reg = 0x00,
.pwm_update_reg = 0x16,
.global_control_reg = IS31FL32XX_REG_NONE,
.reset_reg = 0x17,
.pwm_register_base = 0x01,
.led_control_register_base = 0x13,
.enable_bits_per_led_control_register = 6,
};
static int is31fl3216_reset(struct is31fl32xx_priv *priv);
static int is31fl3216_software_shutdown(struct is31fl32xx_priv *priv,
bool enable);
static const struct is31fl32xx_chipdef is31fl3216_cdef = {
.channels = 16,
.shutdown_reg = IS31FL32XX_REG_NONE,
.pwm_update_reg = 0xB0,
.global_control_reg = IS31FL32XX_REG_NONE,
.reset_reg = IS31FL32XX_REG_NONE,
.pwm_register_base = 0x10,
.pwm_registers_reversed = true,
.led_control_register_base = 0x01,
.enable_bits_per_led_control_register = 8,
.reset_func = is31fl3216_reset,
.sw_shutdown_func = is31fl3216_software_shutdown,
};
static int is31fl32xx_write(struct is31fl32xx_priv *priv, u8 reg, u8 val)
{
int ret;
dev_dbg(&priv->client->dev, "writing register 0x%02X=0x%02X", reg, val);
ret = i2c_smbus_write_byte_data(priv->client, reg, val);
if (ret) {
dev_err(&priv->client->dev,
"register write to 0x%02X failed (error %d)",
reg, ret);
}
return ret;
}
/*
* Custom reset function for IS31FL3216 because it does not have a RESET
* register the way that the other IS31FL32xx chips do. We don't bother
* writing the GPIO and animation registers, because the registers we
* do write ensure those will have no effect.
*/
static int is31fl3216_reset(struct is31fl32xx_priv *priv)
{
unsigned int i;
int ret;
ret = is31fl32xx_write(priv, IS31FL3216_CONFIG_REG,
IS31FL3216_CONFIG_SSD_ENABLE);
if (ret)
return ret;
for (i = 0; i < priv->cdef->channels; i++) {
ret = is31fl32xx_write(priv, priv->cdef->pwm_register_base+i,
0x00);
if (ret)
return ret;
}
ret = is31fl32xx_write(priv, priv->cdef->pwm_update_reg, 0);
if (ret)
return ret;
ret = is31fl32xx_write(priv, IS31FL3216_LIGHTING_EFFECT_REG, 0x00);
if (ret)
return ret;
ret = is31fl32xx_write(priv, IS31FL3216_CHANNEL_CONFIG_REG, 0x00);
if (ret)
return ret;
return 0;
}
/*
* Custom Software-Shutdown function for IS31FL3216 because it does not have
* a SHUTDOWN register the way that the other IS31FL32xx chips do.
* We don't bother doing a read/modify/write on the CONFIG register because
* we only ever use a value of '0' for the other fields in that register.
*/
static int is31fl3216_software_shutdown(struct is31fl32xx_priv *priv,
bool enable)
{
u8 value = enable ? IS31FL3216_CONFIG_SSD_ENABLE :
IS31FL3216_CONFIG_SSD_DISABLE;
return is31fl32xx_write(priv, IS31FL3216_CONFIG_REG, value);
}
/*
* NOTE: A mutex is not needed in this function because:
* - All referenced data is read-only after probe()
* - The I2C core has a mutex on to protect the bus
* - There are no read/modify/write operations
* - Intervening operations between the write of the PWM register
* and the Update register are harmless.
*
* Example:
* PWM_REG_1 write 16
* UPDATE_REG write 0
* PWM_REG_2 write 128
* UPDATE_REG write 0
* vs:
* PWM_REG_1 write 16
* PWM_REG_2 write 128
* UPDATE_REG write 0
* UPDATE_REG write 0
* are equivalent. Poking the Update register merely applies all PWM
* register writes up to that point.
*/
static int is31fl32xx_brightness_set(struct led_classdev *led_cdev,
enum led_brightness brightness)
{
const struct is31fl32xx_led_data *led_data =
container_of(led_cdev, struct is31fl32xx_led_data, cdev);
const struct is31fl32xx_chipdef *cdef = led_data->priv->cdef;
u8 pwm_register_offset;
int ret;
dev_dbg(led_cdev->dev, "%s: %d\n", __func__, brightness);
/* NOTE: led_data->channel is 1-based */
if (cdef->pwm_registers_reversed)
pwm_register_offset = cdef->channels - led_data->channel;
else
pwm_register_offset = led_data->channel - 1;
ret = is31fl32xx_write(led_data->priv,
cdef->pwm_register_base + pwm_register_offset,
brightness);
if (ret)
return ret;
return is31fl32xx_write(led_data->priv, cdef->pwm_update_reg, 0);
}
static int is31fl32xx_reset_regs(struct is31fl32xx_priv *priv)
{
const struct is31fl32xx_chipdef *cdef = priv->cdef;
int ret;
if (cdef->reset_reg != IS31FL32XX_REG_NONE) {
ret = is31fl32xx_write(priv, cdef->reset_reg, 0);
if (ret)
return ret;
}
if (cdef->reset_func)
return cdef->reset_func(priv);
return 0;
}
static int is31fl32xx_software_shutdown(struct is31fl32xx_priv *priv,
bool enable)
{
const struct is31fl32xx_chipdef *cdef = priv->cdef;
int ret;
if (cdef->shutdown_reg != IS31FL32XX_REG_NONE) {
u8 value = enable ? IS31FL32XX_SHUTDOWN_SSD_ENABLE :
IS31FL32XX_SHUTDOWN_SSD_DISABLE;
ret = is31fl32xx_write(priv, cdef->shutdown_reg, value);
if (ret)
return ret;
}
if (cdef->sw_shutdown_func)
return cdef->sw_shutdown_func(priv, enable);
return 0;
}
static int is31fl32xx_init_regs(struct is31fl32xx_priv *priv)
{
const struct is31fl32xx_chipdef *cdef = priv->cdef;
int ret;
ret = is31fl32xx_reset_regs(priv);
if (ret)
return ret;
/*
* Set enable bit for all channels.
* We will control state with PWM registers alone.
*/
if (cdef->led_control_register_base != IS31FL32XX_REG_NONE) {
u8 value =
GENMASK(cdef->enable_bits_per_led_control_register-1, 0);
u8 num_regs = cdef->channels /
cdef->enable_bits_per_led_control_register;
int i;
for (i = 0; i < num_regs; i++) {
ret = is31fl32xx_write(priv,
cdef->led_control_register_base+i,
value);
if (ret)
return ret;
}
}
ret = is31fl32xx_software_shutdown(priv, false);
if (ret)
return ret;
if (cdef->global_control_reg != IS31FL32XX_REG_NONE) {
ret = is31fl32xx_write(priv, cdef->global_control_reg, 0x00);
if (ret)
return ret;
}
return 0;
}
static inline size_t sizeof_is31fl32xx_priv(int num_leds)
{
return sizeof(struct is31fl32xx_priv) +
(sizeof(struct is31fl32xx_led_data) * num_leds);
}
static int is31fl32xx_parse_child_dt(const struct device *dev,
const struct device_node *child,
struct is31fl32xx_led_data *led_data)
{
struct led_classdev *cdev = &led_data->cdev;
int ret = 0;
u32 reg;
if (of_property_read_string(child, "label", &cdev->name))
cdev->name = child->name;
ret = of_property_read_u32(child, "reg", ®);
if (ret || reg < 1 || reg > led_data->priv->cdef->channels) {
dev_err(dev,
"Child node %s does not have a valid reg property\n",
child->full_name);
return -EINVAL;
}
led_data->channel = reg;
of_property_read_string(child, "linux,default-trigger",
&cdev->default_trigger);
cdev->brightness_set_blocking = is31fl32xx_brightness_set;
return 0;
}
static struct is31fl32xx_led_data *is31fl32xx_find_led_data(
struct is31fl32xx_priv *priv,
u8 channel)
{
size_t i;
for (i = 0; i < priv->num_leds; i++) {
if (priv->leds[i].channel == channel)
return &priv->leds[i];
}
return NULL;
}
static int is31fl32xx_parse_dt(struct device *dev,
struct is31fl32xx_priv *priv)
{
struct device_node *child;
int ret = 0;
for_each_child_of_node(dev->of_node, child) {
struct is31fl32xx_led_data *led_data =
&priv->leds[priv->num_leds];
const struct is31fl32xx_led_data *other_led_data;
led_data->priv = priv;
ret = is31fl32xx_parse_child_dt(dev, child, led_data);
if (ret)
goto err;
/* Detect if channel is already in use by another child */
other_led_data = is31fl32xx_find_led_data(priv,
led_data->channel);
if (other_led_data) {
dev_err(dev,
"%s and %s both attempting to use channel %d\n",
led_data->cdev.name,
other_led_data->cdev.name,
led_data->channel);
goto err;
}
ret = devm_led_classdev_register(dev, &led_data->cdev);
if (ret) {
dev_err(dev, "failed to register PWM led for %s: %d\n",
led_data->cdev.name, ret);
goto err;
}
priv->num_leds++;
}
return 0;
err:
of_node_put(child);
return ret;
}
static const struct of_device_id of_is31fl32xx_match[] = {
{ .compatible = "issi,is31fl3236", .data = &is31fl3236_cdef, },
{ .compatible = "issi,is31fl3235", .data = &is31fl3235_cdef, },
{ .compatible = "issi,is31fl3218", .data = &is31fl3218_cdef, },
{ .compatible = "si-en,sn3218", .data = &is31fl3218_cdef, },
{ .compatible = "issi,is31fl3216", .data = &is31fl3216_cdef, },
{ .compatible = "si-en,sn3216", .data = &is31fl3216_cdef, },
{},
};
MODULE_DEVICE_TABLE(of, of_is31fl32xx_match);
static int is31fl32xx_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
const struct is31fl32xx_chipdef *cdef;
const struct of_device_id *of_dev_id;
struct device *dev = &client->dev;
struct is31fl32xx_priv *priv;
int count;
int ret = 0;
of_dev_id = of_match_device(of_is31fl32xx_match, dev);
if (!of_dev_id)
return -EINVAL;
cdef = of_dev_id->data;
count = of_get_child_count(dev->of_node);
if (!count)
return -EINVAL;
priv = devm_kzalloc(dev, sizeof_is31fl32xx_priv(count),
GFP_KERNEL);
if (!priv)
return -ENOMEM;
priv->client = client;
priv->cdef = cdef;
i2c_set_clientdata(client, priv);
ret = is31fl32xx_init_regs(priv);
if (ret)
return ret;
ret = is31fl32xx_parse_dt(dev, priv);
if (ret)
return ret;
return 0;
}
static int is31fl32xx_remove(struct i2c_client *client)
{
struct is31fl32xx_priv *priv = i2c_get_clientdata(client);
return is31fl32xx_reset_regs(priv);
}
/*
* i2c-core (and modalias) requires that id_table be properly filled,
* even though it is not used for DeviceTree based instantiation.
*/
static const struct i2c_device_id is31fl32xx_id[] = {
{ "is31fl3236" },
{ "is31fl3235" },
{ "is31fl3218" },
{ "sn3218" },
{ "is31fl3216" },
{ "sn3216" },
{},
};
MODULE_DEVICE_TABLE(i2c, is31fl32xx_id);
static struct i2c_driver is31fl32xx_driver = {
.driver = {
.name = "is31fl32xx",
.of_match_table = of_is31fl32xx_match,
},
.probe = is31fl32xx_probe,
.remove = is31fl32xx_remove,
.id_table = is31fl32xx_id,
};
module_i2c_driver(is31fl32xx_driver);
MODULE_AUTHOR("David Rivshin <drivshin@allworx.com>");
MODULE_DESCRIPTION("ISSI IS31FL32xx LED driver");
MODULE_LICENSE("GPL v2");
