leds: pca995x: Add support for PCA995X chips

The PCA995x chips are I2C controlled LED drivers. Each chip has
up to 16 outputs, each one with an individual 8-bit resolution
PWM for brightness control.

Signed-off-by: Isai Gaspar <isaiezequiel.gaspar@nxp.com>
Signed-off-by: Marek Vasut <marex@denx.de> # Basically rewrite the driver
Link: https://lore.kernel.org/r/20230713163516.21644-2-marex@denx.de
Signed-off-by: Lee Jones <lee@kernel.org>

diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index 6046dfe..b92208e 100644 (file)
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -521,6 +521,15 @@ config LEDS_PCA963X
          LED driver chip accessed via the I2C bus. Supported
          devices include PCA9633 and PCA9634
 
+config LEDS_PCA995X
+       tristate "LED Support for PCA995x I2C chips"
+       depends on LEDS_CLASS
+       depends on I2C
+       help
+         This option enables support for LEDs connected to PCA995x
+         LED driver chips accessed via the I2C bus. Supported
+         devices include PCA9955BTW, PCA9952TW and PCA9955TW.
+
 config LEDS_WM831X_STATUS
        tristate "LED support for status LEDs on WM831x PMICs"
        depends on LEDS_CLASS

diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index d71f122..d7348e8 100644 (file)
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -72,6 +72,7 @@ obj-$(CONFIG_LEDS_OT200)              += leds-ot200.o
 obj-$(CONFIG_LEDS_PCA9532)             += leds-pca9532.o
 obj-$(CONFIG_LEDS_PCA955X)             += leds-pca955x.o
 obj-$(CONFIG_LEDS_PCA963X)             += leds-pca963x.o
+obj-$(CONFIG_LEDS_PCA995X)             += leds-pca995x.o
 obj-$(CONFIG_LEDS_PM8058)              += leds-pm8058.o
 obj-$(CONFIG_LEDS_POWERNV)             += leds-powernv.o
 obj-$(CONFIG_LEDS_PWM)                 += leds-pwm.o

diff --git a/drivers/leds/leds-pca995x.c b/drivers/leds/leds-pca995x.c
new file mode 100644 (file)
index 0000000..3ac99a4
--- /dev/null
+++ b/drivers/leds/leds-pca995x.c
@@ -0,0 +1,204 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * LED driver for PCA995x I2C LED drivers
+ *
+ * Copyright 2011 bct electronic GmbH
+ * Copyright 2013 Qtechnology/AS
+ * Copyright 2022 NXP
+ * Copyright 2023 Marek Vasut
+ */
+
+#include <linux/i2c.h>
+#include <linux/leds.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+
+/* Register definition */
+#define PCA995X_MODE1                  0x00
+#define PCA995X_MODE2                  0x01
+#define PCA995X_LEDOUT0                        0x02
+#define PCA9955B_PWM0                  0x08
+#define PCA9952_PWM0                   0x0A
+#define PCA9952_IREFALL                        0x43
+#define PCA9955B_IREFALL               0x45
+
+/* Auto-increment disabled. Normal mode */
+#define PCA995X_MODE1_CFG              0x00
+
+/* LED select registers determine the source that drives LED outputs */
+#define PCA995X_LED_OFF                        0x0
+#define PCA995X_LED_ON                 0x1
+#define PCA995X_LED_PWM_MODE           0x2
+#define PCA995X_LDRX_MASK              0x3
+#define PCA995X_LDRX_BITS              2
+
+#define PCA995X_MAX_OUTPUTS            16
+#define PCA995X_OUTPUTS_PER_REG                4
+
+#define PCA995X_IREFALL_FULL_CFG       0xFF
+#define PCA995X_IREFALL_HALF_CFG       (PCA995X_IREFALL_FULL_CFG / 2)
+
+#define PCA995X_TYPE_NON_B             0
+#define PCA995X_TYPE_B                 1
+
+#define ldev_to_led(c) container_of(c, struct pca995x_led, ldev)
+
+struct pca995x_led {
+       unsigned int led_no;
+       struct led_classdev ldev;
+       struct pca995x_chip *chip;
+};
+
+struct pca995x_chip {
+       struct regmap *regmap;
+       struct pca995x_led leds[PCA995X_MAX_OUTPUTS];
+       int btype;
+};
+
+static int pca995x_brightness_set(struct led_classdev *led_cdev,
+                                 enum led_brightness brightness)
+{
+       struct pca995x_led *led = ldev_to_led(led_cdev);
+       struct pca995x_chip *chip = led->chip;
+       u8 ledout_addr, pwmout_addr;
+       int shift, ret;
+
+       pwmout_addr = (chip->btype ? PCA9955B_PWM0 : PCA9952_PWM0) + led->led_no;
+       ledout_addr = PCA995X_LEDOUT0 + (led->led_no / PCA995X_OUTPUTS_PER_REG);
+       shift = PCA995X_LDRX_BITS * (led->led_no % PCA995X_OUTPUTS_PER_REG);
+
+       switch (brightness) {
+       case LED_FULL:
+               return regmap_update_bits(chip->regmap, ledout_addr,
+                                         PCA995X_LDRX_MASK << shift,
+                                         PCA995X_LED_ON << shift);
+       case LED_OFF:
+               return regmap_update_bits(chip->regmap, ledout_addr,
+                                         PCA995X_LDRX_MASK << shift, 0);
+       default:
+               /* Adjust brightness as per user input by changing individual PWM */
+               ret = regmap_write(chip->regmap, pwmout_addr, brightness);
+               if (ret)
+                       return ret;
+
+               /*
+                * Change LDRx configuration to individual brightness via PWM.
+                * LED will stop blinking if it's doing so.
+                */
+               return regmap_update_bits(chip->regmap, ledout_addr,
+                                         PCA995X_LDRX_MASK << shift,
+                                         PCA995X_LED_PWM_MODE << shift);
+       }
+}
+
+static const struct regmap_config pca995x_regmap = {
+       .reg_bits = 8,
+       .val_bits = 8,
+       .max_register = 0x49,
+};
+
+static int pca995x_probe(struct i2c_client *client)
+{
+       struct fwnode_handle *led_fwnodes[PCA995X_MAX_OUTPUTS] = { 0 };
+       struct fwnode_handle *np, *child;
+       struct device *dev = &client->dev;
+       struct pca995x_chip *chip;
+       struct pca995x_led *led;
+       int i, btype, reg, ret;
+
+       btype = (unsigned long)device_get_match_data(&client->dev);
+
+       np = dev_fwnode(dev);
+       if (!np)
+               return -ENODEV;
+
+       chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
+       if (!chip)
+               return -ENOMEM;
+
+       chip->btype = btype;
+       chip->regmap = devm_regmap_init_i2c(client, &pca995x_regmap);
+       if (IS_ERR(chip->regmap))
+               return PTR_ERR(chip->regmap);
+
+       i2c_set_clientdata(client, chip);
+
+       fwnode_for_each_available_child_node(np, child) {
+               ret = fwnode_property_read_u32(child, "reg", &reg);
+               if (ret) {
+                       fwnode_handle_put(child);
+                       return ret;
+               }
+
+               if (reg < 0 || reg >= PCA995X_MAX_OUTPUTS || led_fwnodes[reg]) {
+                       fwnode_handle_put(child);
+                       return -EINVAL;
+               }
+
+               led = &chip->leds[reg];
+               led_fwnodes[reg] = child;
+               led->chip = chip;
+               led->led_no = reg;
+               led->ldev.brightness_set_blocking = pca995x_brightness_set;
+               led->ldev.max_brightness = 255;
+       }
+
+       for (i = 0; i < PCA995X_MAX_OUTPUTS; i++) {
+               struct led_init_data init_data = {};
+
+               if (!led_fwnodes[i])
+                       continue;
+
+               init_data.fwnode = led_fwnodes[i];
+
+               ret = devm_led_classdev_register_ext(dev,
+                                                    &chip->leds[i].ldev,
+                                                    &init_data);
+               if (ret < 0) {
+                       fwnode_handle_put(child);
+                       return dev_err_probe(dev, ret,
+                                            "Could not register LED %s\n",
+                                            chip->leds[i].ldev.name);
+               }
+       }
+
+       /* Disable LED all-call address and set normal mode */
+       ret = regmap_write(chip->regmap, PCA995X_MODE1, PCA995X_MODE1_CFG);
+       if (ret)
+               return ret;
+
+       /* IREF Output current value for all LEDn outputs */
+       return regmap_write(chip->regmap,
+                           btype ? PCA9955B_IREFALL : PCA9952_IREFALL,
+                           PCA995X_IREFALL_HALF_CFG);
+}
+
+static const struct i2c_device_id pca995x_id[] = {
+       { "pca9952", .driver_data = (kernel_ulong_t)PCA995X_TYPE_NON_B },
+       { "pca9955b", .driver_data = (kernel_ulong_t)PCA995X_TYPE_B },
+       {}
+};
+MODULE_DEVICE_TABLE(i2c, pca995x_id);
+
+static const struct of_device_id pca995x_of_match[] = {
+       { .compatible = "nxp,pca9952",  .data = (void *)PCA995X_TYPE_NON_B },
+       { .compatible = "nxp,pca9955b", .data = (void *)PCA995X_TYPE_B },
+       {},
+};
+MODULE_DEVICE_TABLE(i2c, pca995x_of_match);
+
+static struct i2c_driver pca995x_driver = {
+       .driver = {
+               .name = "leds-pca995x",
+               .of_match_table = pca995x_of_match,
+       },
+       .probe = pca995x_probe,
+       .id_table = pca995x_id,
+};
+module_i2c_driver(pca995x_driver);
+
+MODULE_AUTHOR("Isai Gaspar <isaiezequiel.gaspar@nxp.com>");
+MODULE_DESCRIPTION("PCA995x LED driver");
+MODULE_LICENSE("GPL");