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path: root/drivers/leds/leds-pca955x.c
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Diffstat (limited to 'drivers/leds/leds-pca955x.c')
-rw-r--r--drivers/leds/leds-pca955x.c592
1 files changed, 592 insertions, 0 deletions
diff --git a/drivers/leds/leds-pca955x.c b/drivers/leds/leds-pca955x.c
new file mode 100644
index 000000000..7087ca459
--- /dev/null
+++ b/drivers/leds/leds-pca955x.c
@@ -0,0 +1,592 @@
+// 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, &reg);
+
+ 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", &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");
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-07 02:06:36 +0000