* [PATCH 1/2] led: add pca955x led support
2018-09-05 6:20 [PATCH 0/2] add support for pca955x i2c led drivers Oleg.Karfich
2018-09-05 6:20 ` [PATCH 2/2] led: use max led value in case of led trigger Oleg.Karfich
@ 2018-09-05 6:20 ` Oleg.Karfich
2018-09-07 6:21 ` [PATCH 0/2] add support for pca955x i2c led drivers Sascha Hauer
2 siblings, 0 replies; 4+ messages in thread
From: Oleg.Karfich @ 2018-09-05 6:20 UTC (permalink / raw)
To: barebox; +Cc: Oleg.Karfich
Signed-off-by: Oleg Karfich <oleg.karfich@wago.com>
---
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@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);
--
2.7.4
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