Signed-off-by: Oleg Karfich <oleg.karfich@xxxxxxxx> --- drivers/led/Kconfig | 9 + drivers/led/Makefile | 1 + drivers/led/led-pca955x.c | 421 ++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 431 insertions(+) create mode 100644 drivers/led/led-pca955x.c diff --git a/drivers/led/Kconfig b/drivers/led/Kconfig index 50f0d8f..2a5920a 100644 --- a/drivers/led/Kconfig +++ b/drivers/led/Kconfig @@ -31,4 +31,13 @@ config LED_TRIGGERS This allows to assign certain triggers like heartbeat or network activity to LEDs. +config LED_PCA955X + bool "LED Support for PCA955x I2C chips" + depends on I2C + help + This option enables support for LEDs connected to PCA955x + LED driver chips accessed via the I2C bus. Supported + devices include PCA9550, PCA9551, PCA9552, and PCA9553. + + endif diff --git a/drivers/led/Makefile b/drivers/led/Makefile index 619bbcf..862e173 100644 --- a/drivers/led/Makefile +++ b/drivers/led/Makefile @@ -2,3 +2,4 @@ obj-$(CONFIG_LED) += core.o obj-$(CONFIG_LED_GPIO) += led-gpio.o obj-$(CONFIG_LED_PWM) += led-pwm.o obj-$(CONFIG_LED_TRIGGERS) += led-triggers.o +obj-$(CONFIG_LED_TRIGGERS) += led-pca955x.o diff --git a/drivers/led/led-pca955x.c b/drivers/led/led-pca955x.c new file mode 100644 index 0000000..9c4f796 --- /dev/null +++ b/drivers/led/led-pca955x.c @@ -0,0 +1,421 @@ +/* + * Copyright 2007-2008 Extreme Engineering Solutions, Inc. + * Author: Nate Case <ncase@xxxxxxxxxxx> + * + * Copyright (C) 2018 WAGO Kontakttechnik GmbH & Co. KG <http://global.wago.com> + * Author: Oleg Karfich <oleg.karfich@xxxxxxxx> + * + * 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); -- 2.7.4 _______________________________________________ barebox mailing list barebox@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/barebox
