// SPDX-License-Identifier: GPL-2.0-only
|
/*
|
* Copyright 2007-2008 Extreme Engineering Solutions, Inc.
|
*
|
* Author: Nate Case <ncase@xes-inc.com>
|
*
|
* LED driver for various PCA955x I2C LED drivers
|
*
|
* Supported devices:
|
*
|
* Device Description 7-bit slave address
|
* ------ ----------- -------------------
|
* PCA9550 2-bit driver 0x60 .. 0x61
|
* PCA9551 8-bit driver 0x60 .. 0x67
|
* PCA9552 16-bit driver 0x60 .. 0x67
|
* PCA9553/01 4-bit driver 0x62
|
* PCA9553/02 4-bit driver 0x63
|
*
|
* Philips PCA955x LED driver chips follow a register map as shown below:
|
*
|
* Control Register Description
|
* ---------------- -----------
|
* 0x0 Input register 0
|
* ..
|
* NUM_INPUT_REGS - 1 Last Input register X
|
*
|
* NUM_INPUT_REGS Frequency prescaler 0
|
* NUM_INPUT_REGS + 1 PWM register 0
|
* NUM_INPUT_REGS + 2 Frequency prescaler 1
|
* NUM_INPUT_REGS + 3 PWM register 1
|
*
|
* NUM_INPUT_REGS + 4 LED selector 0
|
* NUM_INPUT_REGS + 4
|
* + NUM_LED_REGS - 1 Last LED selector
|
*
|
* where NUM_INPUT_REGS and NUM_LED_REGS vary depending on how many
|
* bits the chip supports.
|
*/
|
|
#include <linux/ctype.h>
|
#include <linux/delay.h>
|
#include <linux/err.h>
|
#include <linux/gpio/driver.h>
|
#include <linux/i2c.h>
|
#include <linux/leds.h>
|
#include <linux/module.h>
|
#include <linux/of.h>
|
#include <linux/property.h>
|
#include <linux/slab.h>
|
#include <linux/string.h>
|
|
#include <dt-bindings/leds/leds-pca955x.h>
|
|
/* LED select registers determine the source that drives LED outputs */
|
#define PCA955X_LS_LED_ON 0x0 /* Output LOW */
|
#define PCA955X_LS_LED_OFF 0x1 /* Output HI-Z */
|
#define PCA955X_LS_BLINK0 0x2 /* Blink at PWM0 rate */
|
#define PCA955X_LS_BLINK1 0x3 /* Blink at PWM1 rate */
|
|
#define PCA955X_GPIO_INPUT LED_OFF
|
#define PCA955X_GPIO_HIGH LED_OFF
|
#define PCA955X_GPIO_LOW LED_FULL
|
|
enum pca955x_type {
|
pca9550,
|
pca9551,
|
pca9552,
|
ibm_pca9552,
|
pca9553,
|
};
|
|
struct pca955x_chipdef {
|
int bits;
|
u8 slv_addr; /* 7-bit slave address mask */
|
int slv_addr_shift; /* Number of bits to ignore */
|
};
|
|
static struct pca955x_chipdef pca955x_chipdefs[] = {
|
[pca9550] = {
|
.bits = 2,
|
.slv_addr = /* 110000x */ 0x60,
|
.slv_addr_shift = 1,
|
},
|
[pca9551] = {
|
.bits = 8,
|
.slv_addr = /* 1100xxx */ 0x60,
|
.slv_addr_shift = 3,
|
},
|
[pca9552] = {
|
.bits = 16,
|
.slv_addr = /* 1100xxx */ 0x60,
|
.slv_addr_shift = 3,
|
},
|
[ibm_pca9552] = {
|
.bits = 16,
|
.slv_addr = /* 0110xxx */ 0x30,
|
.slv_addr_shift = 3,
|
},
|
[pca9553] = {
|
.bits = 4,
|
.slv_addr = /* 110001x */ 0x62,
|
.slv_addr_shift = 1,
|
},
|
};
|
|
static const struct i2c_device_id pca955x_id[] = {
|
{ "pca9550", pca9550 },
|
{ "pca9551", pca9551 },
|
{ "pca9552", pca9552 },
|
{ "ibm-pca9552", ibm_pca9552 },
|
{ "pca9553", pca9553 },
|
{ }
|
};
|
MODULE_DEVICE_TABLE(i2c, pca955x_id);
|
|
struct pca955x {
|
struct mutex lock;
|
struct pca955x_led *leds;
|
struct pca955x_chipdef *chipdef;
|
struct i2c_client *client;
|
#ifdef CONFIG_LEDS_PCA955X_GPIO
|
struct gpio_chip gpio;
|
#endif
|
};
|
|
struct pca955x_led {
|
struct pca955x *pca955x;
|
struct led_classdev led_cdev;
|
int led_num; /* 0 .. 15 potentially */
|
char name[32];
|
u32 type;
|
const char *default_trigger;
|
};
|
|
struct pca955x_platform_data {
|
struct pca955x_led *leds;
|
int num_leds;
|
};
|
|
/* 8 bits per input register */
|
static inline int pca95xx_num_input_regs(int bits)
|
{
|
return (bits + 7) / 8;
|
}
|
|
/* 4 bits per LED selector register */
|
static inline int pca95xx_num_led_regs(int bits)
|
{
|
return (bits + 3) / 4;
|
}
|
|
/*
|
* Return an LED selector register value based on an existing one, with
|
* the appropriate 2-bit state value set for the given LED number (0-3).
|
*/
|
static inline u8 pca955x_ledsel(u8 oldval, int led_num, int state)
|
{
|
return (oldval & (~(0x3 << (led_num << 1)))) |
|
((state & 0x3) << (led_num << 1));
|
}
|
|
/*
|
* Write to frequency prescaler register, used to program the
|
* period of the PWM output. period = (PSCx + 1) / 38
|
*/
|
static int pca955x_write_psc(struct i2c_client *client, int n, u8 val)
|
{
|
struct pca955x *pca955x = i2c_get_clientdata(client);
|
int ret;
|
|
ret = i2c_smbus_write_byte_data(client,
|
pca95xx_num_input_regs(pca955x->chipdef->bits) + 2*n,
|
val);
|
if (ret < 0)
|
dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n",
|
__func__, n, val, ret);
|
return ret;
|
}
|
|
/*
|
* Write to PWM register, which determines the duty cycle of the
|
* output. LED is OFF when the count is less than the value of this
|
* register, and ON when it is greater. If PWMx == 0, LED is always OFF.
|
*
|
* Duty cycle is (256 - PWMx) / 256
|
*/
|
static int pca955x_write_pwm(struct i2c_client *client, int n, u8 val)
|
{
|
struct pca955x *pca955x = i2c_get_clientdata(client);
|
int ret;
|
|
ret = i2c_smbus_write_byte_data(client,
|
pca95xx_num_input_regs(pca955x->chipdef->bits) + 1 + 2*n,
|
val);
|
if (ret < 0)
|
dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n",
|
__func__, n, val, ret);
|
return ret;
|
}
|
|
/*
|
* Write to LED selector register, which determines the source that
|
* drives the LED output.
|
*/
|
static int pca955x_write_ls(struct i2c_client *client, int n, u8 val)
|
{
|
struct pca955x *pca955x = i2c_get_clientdata(client);
|
int ret;
|
|
ret = i2c_smbus_write_byte_data(client,
|
pca95xx_num_input_regs(pca955x->chipdef->bits) + 4 + n,
|
val);
|
if (ret < 0)
|
dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n",
|
__func__, n, val, ret);
|
return ret;
|
}
|
|
/*
|
* Read the LED selector register, which determines the source that
|
* drives the LED output.
|
*/
|
static int pca955x_read_ls(struct i2c_client *client, int n, u8 *val)
|
{
|
struct pca955x *pca955x = i2c_get_clientdata(client);
|
int ret;
|
|
ret = i2c_smbus_read_byte_data(client,
|
pca95xx_num_input_regs(pca955x->chipdef->bits) + 4 + n);
|
if (ret < 0) {
|
dev_err(&client->dev, "%s: reg 0x%x, err %d\n",
|
__func__, n, ret);
|
return ret;
|
}
|
*val = (u8)ret;
|
return 0;
|
}
|
|
static int pca955x_led_set(struct led_classdev *led_cdev,
|
enum led_brightness value)
|
{
|
struct pca955x_led *pca955x_led;
|
struct pca955x *pca955x;
|
u8 ls;
|
int chip_ls; /* which LSx to use (0-3 potentially) */
|
int ls_led; /* which set of bits within LSx to use (0-3) */
|
int ret;
|
|
pca955x_led = container_of(led_cdev, struct pca955x_led, led_cdev);
|
pca955x = pca955x_led->pca955x;
|
|
chip_ls = pca955x_led->led_num / 4;
|
ls_led = pca955x_led->led_num % 4;
|
|
mutex_lock(&pca955x->lock);
|
|
ret = pca955x_read_ls(pca955x->client, chip_ls, &ls);
|
if (ret)
|
goto out;
|
|
switch (value) {
|
case LED_FULL:
|
ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_LED_ON);
|
break;
|
case LED_OFF:
|
ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_LED_OFF);
|
break;
|
case LED_HALF:
|
ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_BLINK0);
|
break;
|
default:
|
/*
|
* Use PWM1 for all other values. This has the unwanted
|
* side effect of making all LEDs on the chip share the
|
* same brightness level if set to a value other than
|
* OFF, HALF, or FULL. But, this is probably better than
|
* just turning off for all other values.
|
*/
|
ret = pca955x_write_pwm(pca955x->client, 1, 255 - value);
|
if (ret)
|
goto out;
|
ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_BLINK1);
|
break;
|
}
|
|
ret = pca955x_write_ls(pca955x->client, chip_ls, ls);
|
|
out:
|
mutex_unlock(&pca955x->lock);
|
|
return ret;
|
}
|
|
#ifdef CONFIG_LEDS_PCA955X_GPIO
|
/*
|
* Read the INPUT register, which contains the state of LEDs.
|
*/
|
static int pca955x_read_input(struct i2c_client *client, int n, u8 *val)
|
{
|
int ret = i2c_smbus_read_byte_data(client, n);
|
|
if (ret < 0) {
|
dev_err(&client->dev, "%s: reg 0x%x, err %d\n",
|
__func__, n, ret);
|
return ret;
|
}
|
*val = (u8)ret;
|
return 0;
|
|
}
|
|
static int pca955x_gpio_request_pin(struct gpio_chip *gc, unsigned int offset)
|
{
|
struct pca955x *pca955x = gpiochip_get_data(gc);
|
struct pca955x_led *led = &pca955x->leds[offset];
|
|
if (led->type == PCA955X_TYPE_GPIO)
|
return 0;
|
|
return -EBUSY;
|
}
|
|
static int pca955x_set_value(struct gpio_chip *gc, unsigned int offset,
|
int val)
|
{
|
struct pca955x *pca955x = gpiochip_get_data(gc);
|
struct pca955x_led *led = &pca955x->leds[offset];
|
|
if (val)
|
return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_HIGH);
|
|
return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_LOW);
|
}
|
|
static void pca955x_gpio_set_value(struct gpio_chip *gc, unsigned int offset,
|
int val)
|
{
|
pca955x_set_value(gc, offset, val);
|
}
|
|
static int pca955x_gpio_get_value(struct gpio_chip *gc, unsigned int offset)
|
{
|
struct pca955x *pca955x = gpiochip_get_data(gc);
|
struct pca955x_led *led = &pca955x->leds[offset];
|
u8 reg = 0;
|
|
/* There is nothing we can do about errors */
|
pca955x_read_input(pca955x->client, led->led_num / 8, ®);
|
|
return !!(reg & (1 << (led->led_num % 8)));
|
}
|
|
static int pca955x_gpio_direction_input(struct gpio_chip *gc,
|
unsigned int offset)
|
{
|
struct pca955x *pca955x = gpiochip_get_data(gc);
|
struct pca955x_led *led = &pca955x->leds[offset];
|
|
/* To use as input ensure pin is not driven. */
|
return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_INPUT);
|
}
|
|
static int pca955x_gpio_direction_output(struct gpio_chip *gc,
|
unsigned int offset, int val)
|
{
|
return pca955x_set_value(gc, offset, val);
|
}
|
#endif /* CONFIG_LEDS_PCA955X_GPIO */
|
|
static struct pca955x_platform_data *
|
pca955x_get_pdata(struct i2c_client *client, struct pca955x_chipdef *chip)
|
{
|
struct pca955x_platform_data *pdata;
|
struct fwnode_handle *child;
|
int count;
|
|
count = device_get_child_node_count(&client->dev);
|
if (!count || count > chip->bits)
|
return ERR_PTR(-ENODEV);
|
|
pdata = devm_kzalloc(&client->dev, sizeof(*pdata), GFP_KERNEL);
|
if (!pdata)
|
return ERR_PTR(-ENOMEM);
|
|
pdata->leds = devm_kcalloc(&client->dev,
|
chip->bits, sizeof(struct pca955x_led),
|
GFP_KERNEL);
|
if (!pdata->leds)
|
return ERR_PTR(-ENOMEM);
|
|
device_for_each_child_node(&client->dev, child) {
|
const char *name;
|
u32 reg;
|
int res;
|
|
res = fwnode_property_read_u32(child, "reg", ®);
|
if ((res != 0) || (reg >= chip->bits))
|
continue;
|
|
res = fwnode_property_read_string(child, "label", &name);
|
if ((res != 0) && is_of_node(child))
|
name = to_of_node(child)->name;
|
|
snprintf(pdata->leds[reg].name, sizeof(pdata->leds[reg].name),
|
"%s", name);
|
|
pdata->leds[reg].type = PCA955X_TYPE_LED;
|
fwnode_property_read_u32(child, "type", &pdata->leds[reg].type);
|
fwnode_property_read_string(child, "linux,default-trigger",
|
&pdata->leds[reg].default_trigger);
|
}
|
|
pdata->num_leds = chip->bits;
|
|
return pdata;
|
}
|
|
static const struct of_device_id of_pca955x_match[] = {
|
{ .compatible = "nxp,pca9550", .data = (void *)pca9550 },
|
{ .compatible = "nxp,pca9551", .data = (void *)pca9551 },
|
{ .compatible = "nxp,pca9552", .data = (void *)pca9552 },
|
{ .compatible = "ibm,pca9552", .data = (void *)ibm_pca9552 },
|
{ .compatible = "nxp,pca9553", .data = (void *)pca9553 },
|
{},
|
};
|
MODULE_DEVICE_TABLE(of, of_pca955x_match);
|
|
static int pca955x_probe(struct i2c_client *client,
|
const struct i2c_device_id *id)
|
{
|
struct pca955x *pca955x;
|
struct pca955x_led *pca955x_led;
|
struct pca955x_chipdef *chip;
|
struct i2c_adapter *adapter;
|
int i, err;
|
struct pca955x_platform_data *pdata;
|
int ngpios = 0;
|
|
chip = &pca955x_chipdefs[id->driver_data];
|
adapter = client->adapter;
|
pdata = dev_get_platdata(&client->dev);
|
if (!pdata) {
|
pdata = pca955x_get_pdata(client, chip);
|
if (IS_ERR(pdata))
|
return PTR_ERR(pdata);
|
}
|
|
/* Make sure the slave address / chip type combo given is possible */
|
if ((client->addr & ~((1 << chip->slv_addr_shift) - 1)) !=
|
chip->slv_addr) {
|
dev_err(&client->dev, "invalid slave address %02x\n",
|
client->addr);
|
return -ENODEV;
|
}
|
|
dev_info(&client->dev, "leds-pca955x: Using %s %d-bit LED driver at "
|
"slave address 0x%02x\n",
|
client->name, chip->bits, client->addr);
|
|
if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
|
return -EIO;
|
|
if (pdata->num_leds != chip->bits) {
|
dev_err(&client->dev,
|
"board info claims %d LEDs on a %d-bit chip\n",
|
pdata->num_leds, chip->bits);
|
return -ENODEV;
|
}
|
|
pca955x = devm_kzalloc(&client->dev, sizeof(*pca955x), GFP_KERNEL);
|
if (!pca955x)
|
return -ENOMEM;
|
|
pca955x->leds = devm_kcalloc(&client->dev,
|
chip->bits, sizeof(*pca955x_led), GFP_KERNEL);
|
if (!pca955x->leds)
|
return -ENOMEM;
|
|
i2c_set_clientdata(client, pca955x);
|
|
mutex_init(&pca955x->lock);
|
pca955x->client = client;
|
pca955x->chipdef = chip;
|
|
for (i = 0; i < chip->bits; i++) {
|
pca955x_led = &pca955x->leds[i];
|
pca955x_led->led_num = i;
|
pca955x_led->pca955x = pca955x;
|
pca955x_led->type = pdata->leds[i].type;
|
|
switch (pca955x_led->type) {
|
case PCA955X_TYPE_NONE:
|
break;
|
case PCA955X_TYPE_GPIO:
|
ngpios++;
|
break;
|
case PCA955X_TYPE_LED:
|
/*
|
* Platform data can specify LED names and
|
* default triggers
|
*/
|
if (pdata->leds[i].name[0] == '\0')
|
snprintf(pdata->leds[i].name,
|
sizeof(pdata->leds[i].name), "%d", i);
|
|
snprintf(pca955x_led->name,
|
sizeof(pca955x_led->name), "pca955x:%s",
|
pdata->leds[i].name);
|
|
if (pdata->leds[i].default_trigger)
|
pca955x_led->led_cdev.default_trigger =
|
pdata->leds[i].default_trigger;
|
|
pca955x_led->led_cdev.name = pca955x_led->name;
|
pca955x_led->led_cdev.brightness_set_blocking =
|
pca955x_led_set;
|
|
err = devm_led_classdev_register(&client->dev,
|
&pca955x_led->led_cdev);
|
if (err)
|
return err;
|
|
/* Turn off LED */
|
err = pca955x_led_set(&pca955x_led->led_cdev, LED_OFF);
|
if (err)
|
return err;
|
}
|
}
|
|
/* PWM0 is used for half brightness or 50% duty cycle */
|
err = pca955x_write_pwm(client, 0, 255 - LED_HALF);
|
if (err)
|
return err;
|
|
/* PWM1 is used for variable brightness, default to OFF */
|
err = pca955x_write_pwm(client, 1, 0);
|
if (err)
|
return err;
|
|
/* Set to fast frequency so we do not see flashing */
|
err = pca955x_write_psc(client, 0, 0);
|
if (err)
|
return err;
|
err = pca955x_write_psc(client, 1, 0);
|
if (err)
|
return err;
|
|
#ifdef CONFIG_LEDS_PCA955X_GPIO
|
if (ngpios) {
|
pca955x->gpio.label = "gpio-pca955x";
|
pca955x->gpio.direction_input = pca955x_gpio_direction_input;
|
pca955x->gpio.direction_output = pca955x_gpio_direction_output;
|
pca955x->gpio.set = pca955x_gpio_set_value;
|
pca955x->gpio.get = pca955x_gpio_get_value;
|
pca955x->gpio.request = pca955x_gpio_request_pin;
|
pca955x->gpio.can_sleep = 1;
|
pca955x->gpio.base = -1;
|
pca955x->gpio.ngpio = ngpios;
|
pca955x->gpio.parent = &client->dev;
|
pca955x->gpio.owner = THIS_MODULE;
|
|
err = devm_gpiochip_add_data(&client->dev, &pca955x->gpio,
|
pca955x);
|
if (err) {
|
/* Use data->gpio.dev as a flag for freeing gpiochip */
|
pca955x->gpio.parent = NULL;
|
dev_warn(&client->dev, "could not add gpiochip\n");
|
return err;
|
}
|
dev_info(&client->dev, "gpios %i...%i\n",
|
pca955x->gpio.base, pca955x->gpio.base +
|
pca955x->gpio.ngpio - 1);
|
}
|
#endif
|
|
return 0;
|
}
|
|
static struct i2c_driver pca955x_driver = {
|
.driver = {
|
.name = "leds-pca955x",
|
.of_match_table = of_pca955x_match,
|
},
|
.probe = pca955x_probe,
|
.id_table = pca955x_id,
|
};
|
|
module_i2c_driver(pca955x_driver);
|
|
MODULE_AUTHOR("Nate Case <ncase@xes-inc.com>");
|
MODULE_DESCRIPTION("PCA955x LED driver");
|
MODULE_LICENSE("GPL v2");
|
