/*
* Copyright 2007-2008 Extreme Engineering Solutions, Inc.
* Author: Nate Case <ncase@xes-inc.com>
*
* Copyright (C) 2018 WAGO Kontakttechnik GmbH & Co. KG <http://global.wago.com>
* Author: Oleg Karfich <oleg.karfich@wago.com>
*
* 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.
*
* 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.
*
* This code was ported from linux-4.18 kernel driver.
* Orginal code with it's copyright info can be found in
* drivers/leds/leds-pca955x.c
*
* 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 <common.h>
#include <init.h>
#include <led.h>
#include <malloc.h>
#include <i2c/i2c.h>
#include <of_device.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 */
enum led_brightness {
LED_OFF = 0,
LED_HALF = 127,
LED_FULL = 255,
};
enum pca955x_type {
pca9550,
pca9551,
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,
},
[pca9553] = {
.bits = 4,
.slv_addr = /* 110001x */ 0x62,
.slv_addr_shift = 1,
},
};
static const struct platform_device_id led_pca955x_id[] = {
{ "pca9550", pca9550 },
{ "pca9551", pca9551 },
{ "pca9552", pca9552 },
{ "pca9553", pca9553 },
{ }
};
struct pca955x {
struct pca955x_led *leds;
struct pca955x_chipdef *chipdef;
struct i2c_client *client;
};
struct pca955x_led {
struct pca955x *pca955x;
struct led led_cdev;
int led_num; /* 0 .. 15 potentially */
char name[32];
};
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);
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 void pca955x_led_set(struct led *led_cdev, unsigned int 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;
ret = pca955x_read_ls(pca955x->client, chip_ls, &ls);
if (ret)
return;
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)
return;
ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_BLINK1);
break;
}
pca955x_write_ls(pca955x->client, chip_ls, ls);
}
static struct pca955x_platform_data *
led_pca955x_pdata_of_init(struct device_node *np, struct pca955x *pca955x)
{
struct device_node *child;
struct pca955x_chipdef *chip = pca955x->chipdef;
struct pca955x_platform_data *pdata;
int count, err;
count = of_get_child_count(np);
if (!count || count > chip->bits)
return ERR_PTR(-ENODEV);
pdata = xzalloc(sizeof(*pdata));
if (!pdata)
return ERR_PTR(-ENOMEM);
pdata->leds = xzalloc(chip->bits * sizeof(struct pca955x_led));
if (!pdata->leds)
return ERR_PTR(-ENOMEM);
for_each_child_of_node(np, child) {
struct pca955x_led *pca955x_led;
const char *name;
u32 reg;
int res;
res = of_property_read_u32(child, "reg", ®);
if ((res != 0) || (reg >= chip->bits))
continue;
pca955x_led = &pdata->leds[reg];
pca955x_led->led_num = reg;
pca955x_led->pca955x = pca955x;
if (of_property_read_string(child, "label", &name))
name = child->name;
snprintf(pca955x_led->name, sizeof(pca955x_led->name),
"%s", name);
pca955x_led->led_cdev.name = pca955x_led->name;
pca955x_led->led_cdev.set = pca955x_led_set;
pca955x_led->led_cdev.num = pca955x_led->led_num;
pca955x_led->led_cdev.max_value = 255;
err = led_register(&pca955x_led->led_cdev);
if (err)
return ERR_PTR(err);
/* Turn off LED */
pca955x_led_set(&pca955x_led->led_cdev, LED_OFF);
led_of_parse_trigger(&pca955x_led->led_cdev, child);
}
pdata->num_leds = count;
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 = "nxp,pca9553", .data = (void *)pca9553 },
{},
};
static int led_pca955x_probe(struct device_d *dev)
{
struct pca955x *pca955x;
struct pca955x_led *pca955x_led;
struct pca955x_chipdef *chip;
struct i2c_client *client;
int err;
struct pca955x_platform_data *pdata;
chip = &pca955x_chipdefs[dev->id_entry->driver_data];
client = to_i2c_client(dev);
/* 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(dev, "invalid slave address %02x\n", client->addr);
return -ENODEV;
}
dev_info(dev, "leds-pca955x: Using %s %d-bit LED driver at "
"slave address 0x%02x\n",
client->dev.name, chip->bits, client->addr);
pca955x = xzalloc(sizeof(*pca955x));
if (!pca955x)
return -ENOMEM;
pca955x->leds = xzalloc(chip->bits * sizeof(*pca955x_led));
if (!pca955x->leds)
return -ENOMEM;
i2c_set_clientdata(client, pca955x);
pca955x->client = client;
pca955x->chipdef = chip;
pdata = led_pca955x_pdata_of_init(dev->device_node, pca955x);
if (IS_ERR(pdata))
return PTR_ERR(pdata);
if (pdata->num_leds != chip->bits)
dev_warn(dev, "board info claims %d LEDs on a %d-bit chip\n",
pdata->num_leds, chip->bits);
/* 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;
return 0;
}
static struct driver_d led_pca955x_driver = {
.name = "led-pca955x",
.probe = led_pca955x_probe,
.id_table = led_pca955x_id,
.of_compatible = DRV_OF_COMPAT(of_pca955x_match),
};
static int __init led_pca955x_init(void)
{
return i2c_driver_register(&led_pca955x_driver);
}
device_initcall(led_pca955x_init);
