// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright 2007-2008 Extreme Engineering Solutions, Inc.
*
* Author: Nate Case <[email protected]>
*
* 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/bitops.h>
#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 const 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,
},
};
struct pca955x {
struct mutex lock;
struct pca955x_led *leds;
const struct pca955x_chipdef *chipdef;
struct i2c_client *client;
unsigned long active_pins;
#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 */
u32 type;
enum led_default_state default_state;
struct fwnode_handle *fwnode;
};
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;
}
/*
* 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);
u8 cmd = pca95xx_num_input_regs(pca955x->chipdef->bits) + (2 * n);
int ret;
ret = i2c_smbus_write_byte_data(client, cmd, 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);
u8 cmd = pca95xx_num_input_regs(pca955x->chipdef->bits) + 1 + (2 * n);
int ret;
ret = i2c_smbus_write_byte_data(client, cmd, 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);
u8 cmd = pca95xx_num_input_regs(pca955x->chipdef->bits) + 4 + n;
int ret;
ret = i2c_smbus_write_byte_data(client, cmd, 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);
u8 cmd = pca95xx_num_input_regs(pca955x->chipdef->bits) + 4 + n;
int ret;
ret = i2c_smbus_read_byte_data(client, cmd);
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_read_pwm(struct i2c_client *client, int n, u8 *val)
{
struct pca955x *pca955x = i2c_get_clientdata(client);
u8 cmd = pca95xx_num_input_regs(pca955x->chipdef->bits) + 1 + (2 * n);
int ret;
ret = i2c_smbus_read_byte_data(client, cmd);
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 enum led_brightness pca955x_led_get(struct led_classdev *led_cdev)
{
struct pca955x_led *pca955x_led = container_of(led_cdev,
struct pca955x_led,
led_cdev);
struct pca955x *pca955x = pca955x_led->pca955x;
u8 ls, pwm;
int ret;
ret = pca955x_read_ls(pca955x->client, pca955x_led->led_num / 4, &ls);
if (ret)
return ret;
ls = (ls >> ((pca955x_led->led_num % 4) << 1)) & 0x3;
switch (ls) {
case PCA955X_LS_LED_ON:
ret = LED_FULL;
break;
case PCA955X_LS_LED_OFF:
ret = LED_OFF;
break;
case PCA955X_LS_BLINK0:
ret = LED_HALF;
break;
case PCA955X_LS_BLINK1:
ret = pca955x_read_pwm(pca955x->client, 1, &pwm);
if (ret)
return ret;
ret = 255 - pwm;
break;
}
return ret;
}
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);
return test_and_set_bit(offset, &pca955x->active_pins) ? -EBUSY : 0;
}
static void pca955x_gpio_free_pin(struct gpio_chip *gc, unsigned int offset)
{
struct pca955x *pca955x = gpiochip_get_data(gc);
clear_bit(offset, &pca955x->active_pins);
}
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, const struct pca955x_chipdef *chip)
{
struct pca955x_platform_data *pdata;
struct pca955x_led *led;
struct fwnode_handle *child;
int count;
count = device_get_child_node_count(&client->dev);
if (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) {
u32 reg;
int res;
res = fwnode_property_read_u32(child, "reg", ®);
if ((res != 0) || (reg >= chip->bits))
continue;
led = &pdata->leds[reg];
led->type = PCA955X_TYPE_LED;
led->fwnode = child;
led->default_state = led_init_default_state_get(child);
fwnode_property_read_u32(child, "type", &led->type);
}
pdata->num_leds = chip->bits;
return pdata;
}
static int pca955x_probe(struct i2c_client *client)
{
struct pca955x *pca955x;
struct pca955x_led *pca955x_led;
const struct pca955x_chipdef *chip;
struct led_classdev *led;
struct led_init_data init_data;
struct i2c_adapter *adapter;
int i, err;
struct pca955x_platform_data *pdata;
bool set_default_label = false;
bool keep_pwm = false;
char default_label[8];
chip = i2c_get_match_data(client);
if (!chip)
return dev_err_probe(&client->dev, -ENODEV, "unknown chip\n");
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;
init_data.devname_mandatory = false;
init_data.devicename = "pca955x";
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:
case PCA955X_TYPE_GPIO:
break;
case PCA955X_TYPE_LED:
led = &pca955x_led->led_cdev;
led->brightness_set_blocking = pca955x_led_set;
led->brightness_get = pca955x_led_get;
if (pdata->leds[i].default_state == LEDS_DEFSTATE_OFF) {
err = pca955x_led_set(led, LED_OFF);
if (err)
return err;
} else if (pdata->leds[i].default_state == LEDS_DEFSTATE_ON) {
err = pca955x_led_set(led, LED_FULL);
if (err)
return err;
}
init_data.fwnode = pdata->leds[i].fwnode;
if (is_of_node(init_data.fwnode)) {
if (to_of_node(init_data.fwnode)->name[0] ==
'\0')
set_default_label = true;
else
set_default_label = false;
} else {
set_default_label = true;
}
if (set_default_label) {
snprintf(default_label, sizeof(default_label),
"%d", i);
init_data.default_label = default_label;
} else {
init_data.default_label = NULL;
}
err = devm_led_classdev_register_ext(&client->dev, led,
&init_data);
if (err)
return err;
set_bit(i, &pca955x->active_pins);
/*
* For default-state == "keep", let the core update the
* brightness from the hardware, then check the
* brightness to see if it's using PWM1. If so, PWM1
* should not be written below.
*/
if (pdata->leds[i].default_state == LEDS_DEFSTATE_KEEP) {
if (led->brightness != LED_FULL &&
led->brightness != LED_OFF &&
led->brightness != LED_HALF)
keep_pwm = true;
}
}
}
/* PWM0 is used for half brightness or 50% duty cycle */
err = pca955x_write_pwm(client, 0, 255 - LED_HALF);
if (err)
return err;
if (!keep_pwm) {
/* 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
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.free = pca955x_gpio_free_pin;
pca955x->gpio.can_sleep = 1;
pca955x->gpio.base = -1;
pca955x->gpio.ngpio = chip->bits;
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 const struct i2c_device_id pca955x_id[] = {
{ "pca9550", (kernel_ulong_t)&pca955x_chipdefs[pca9550] },
{ "pca9551", (kernel_ulong_t)&pca955x_chipdefs[pca9551] },
{ "pca9552", (kernel_ulong_t)&pca955x_chipdefs[pca9552] },
{ "ibm-pca9552", (kernel_ulong_t)&pca955x_chipdefs[ibm_pca9552] },
{ "pca9553", (kernel_ulong_t)&pca955x_chipdefs[pca9553] },
{}
};
MODULE_DEVICE_TABLE(i2c, pca955x_id);
static const struct of_device_id of_pca955x_match[] = {
{ .compatible = "nxp,pca9550", .data = &pca955x_chipdefs[pca9550] },
{ .compatible = "nxp,pca9551", .data = &pca955x_chipdefs[pca9551] },
{ .compatible = "nxp,pca9552", .data = &pca955x_chipdefs[pca9552] },
{ .compatible = "ibm,pca9552", .data = &pca955x_chipdefs[ibm_pca9552] },
{ .compatible = "nxp,pca9553", .data = &pca955x_chipdefs[pca9553] },
{}
};
MODULE_DEVICE_TABLE(of, of_pca955x_match);
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 <[email protected]>");
MODULE_DESCRIPTION("PCA955x LED driver");
MODULE_LICENSE("GPL v2");
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