Changes from RFC:
- Removed max-brightness DT property.
- Refer to these devices as "LED controllers" in Kconfig.
- Removed redundant last sentence from Kconfig entry
- Removed unnecessary debug code.
- Do not set led_classdev.brightness to 0 explicitly, as it is
already initialized to 0 by devm_kzalloc().
- Used of_property_read_string() instead of of_get_property().
- Fail immediately on DT parsing error in a child node, rather than
continuing on with the non-faulty ones.
- Added additional comments for some things that might be non-obvious.
- Added constants for the location of the SSD bit in the SHUTDOWN
register, and the 3216's CONFIG register.
- Added special sw_shutdown_func for the 3216 device, as that bit
is in a different register, at a different position, and has reverse
polarity compared to all the other devices.
- Refactored is31fl32xx_init_regs() to separate out some logic into
is31fl32xx_reset_regs() and is31fl32xx_software_shutdown().
[1] https://lkml.org/lkml/2016/3/2/746
drivers/leds/Kconfig | 8 +
drivers/leds/Makefile | 1 +
drivers/leds/leds-is31fl32xx.c | 505 +++++++++++++++++++++++++++++++++++++++++
3 files changed, 514 insertions(+)
create mode 100644 drivers/leds/leds-is31fl32xx.c
diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index 1034696..9c63ba4 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -580,6 +580,14 @@ config LEDS_SN3218
This driver can also be built as a module. If so the module
will be called leds-sn3218.
+config LEDS_IS31FL32XX
+ tristate "LED support for ISSI IS31FL32XX I2C LED controller family"
+ depends on LEDS_CLASS && I2C && OF
+ help
+ Say Y here to include support for ISSI IS31FL32XX LED controllers.
+ They are I2C devices with multiple constant-current channels, each
+ with independent 256-level PWM control.
+
comment "LED driver for blink(1) USB RGB LED is under Special HID drivers (HID_THINGM)"
config LEDS_BLINKM
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index 89c9b6f..3fdf313 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -67,6 +67,7 @@ obj-$(CONFIG_LEDS_KTD2692) += leds-ktd2692.o
obj-$(CONFIG_LEDS_POWERNV) += leds-powernv.o
obj-$(CONFIG_LEDS_SEAD3) += leds-sead3.o
obj-$(CONFIG_LEDS_SN3218) += leds-sn3218.o
+obj-$(CONFIG_LEDS_IS31FL32XX) += leds-is31fl32xx.o
# LED SPI Drivers
obj-$(CONFIG_LEDS_DAC124S085) += leds-dac124s085.o
diff --git a/drivers/leds/leds-is31fl32xx.c b/drivers/leds/leds-is31fl32xx.c
new file mode 100644
index 0000000..49818f0
--- /dev/null
+++ b/drivers/leds/leds-is31fl32xx.c
@@ -0,0 +1,505 @@
+/*
+ * linux/drivers/leds-is31fl32xx.c
+ *
+ * Driver for ISSI IS31FL32xx family of I2C LED controllers
+ *
+ * Copyright 2015 Allworx Corp.
+ *
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Datasheets: http://www.issi.com/US/product-analog-fxled-driver.shtml
+ */
+
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/kernel.h>
+#include <linux/leds.h>
+#include <linux/module.h>
+#include <linux/of_platform.h>
+
+/* Used to indicate a device has no such register */
+#define IS31FL32XX_REG_NONE 0xFF
+
+/* Software Shutdown bit in Shutdown Register */
+#define IS31FL32XX_SHUTDOWN_SSD_ENABLE 0
+#define IS31FL32XX_SHUTDOWN_SSD_DISABLE BIT(0)
+
+/* IS31FL3216 has a number of unique registers */
+#define IS31FL3216_CONFIG_REG 0x00
+#define IS31FL3216_LIGHTING_EFFECT_REG 0x03
+#define IS31FL3216_CHANNEL_CONFIG_REG 0x04
+
+/* Software Shutdown bit in 3216 Config Register */
+#define IS31FL3216_CONFIG_SSD_ENABLE BIT(7)
+#define IS31FL3216_CONFIG_SSD_DISABLE 0
+
+struct is31fl32xx_priv;
+struct is31fl32xx_led_data {
+ struct led_classdev cdev;
+ u8 channel; /* 1-based, max priv->cdef->channels */
+ struct is31fl32xx_priv *priv;
+};
+
+struct is31fl32xx_priv {
+ const struct is31fl32xx_chipdef *cdef;
+ struct i2c_client *client;
+ unsigned int num_leds;
+ struct is31fl32xx_led_data leds[0];
+};
+
+/**
+ * struct is31fl32xx_chipdef - chip-specific attributes
+ * @channels : Number of LED channels
+ * @shutdown_reg : address of Shutdown register (optional)
+ * @pwm_update_reg : address of PWM Update register
+ * @global_control_reg : address of Global Control register (optional)
+ * @reset_reg : address of Reset register (optional)
+ * @pwm_register_base : address of first PWM register
+ * @pwm_registers_reversed: : true if PWM registers count down instead of up
+ * @led_control_register_base : address of first LED control register (optional)
+ * @enable_bits_per_led_control_register: number of LEDs enable bits in each
+ * @reset_func: : pointer to reset function
+ *
+ * For all optional register addresses, the sentinel value %IS31FL32XX_REG_NONE
+ * indicates that this chip has no such register.
+ *
+ * If non-NULL, @reset_func will be called during probing to set all
+ * necessary registers to a known initialization state. This is needed
+ * for chips that do not have a @reset_reg.
+ *
+ * @enable_bits_per_led_control_register must be >=1 if
+ * @led_control_register_base != %IS31FL32XX_REG_NONE.
+ */
+struct is31fl32xx_chipdef {
+ u8 channels;
+ u8 shutdown_reg;
+ u8 pwm_update_reg;
+ u8 global_control_reg;
+ u8 reset_reg;
+ u8 pwm_register_base;
+ bool pwm_registers_reversed;
+ u8 led_control_register_base;
+ u8 enable_bits_per_led_control_register;
+ int (*reset_func)(struct is31fl32xx_priv *priv);
+ int (*sw_shutdown_func)(struct is31fl32xx_priv *priv, bool enable);
+};
+
+static const struct is31fl32xx_chipdef is31fl3236_cdef = {
+ .channels = 36,
+ .shutdown_reg = 0x00,
+ .pwm_update_reg = 0x25,
+ .global_control_reg = 0x4a,
+ .reset_reg = 0x4f,
+ .pwm_register_base = 0x01,
+ .led_control_register_base = 0x26,
+ .enable_bits_per_led_control_register = 1,
+};
+
+static const struct is31fl32xx_chipdef is31fl3235_cdef = {
+ .channels = 28,
+ .shutdown_reg = 0x00,
+ .pwm_update_reg = 0x25,
+ .global_control_reg = 0x4a,
+ .reset_reg = 0x4f,
+ .pwm_register_base = 0x05,
+ .led_control_register_base = 0x2a,
+ .enable_bits_per_led_control_register = 1,
+};
+
+static const struct is31fl32xx_chipdef is31fl3218_cdef = {
+ .channels = 18,
+ .shutdown_reg = 0x00,
+ .pwm_update_reg = 0x16,
+ .global_control_reg = IS31FL32XX_REG_NONE,
+ .reset_reg = 0x17,
+ .pwm_register_base = 0x01,
+ .led_control_register_base = 0x13,
+ .enable_bits_per_led_control_register = 6,
+};
+
+static int is31fl3216_reset(struct is31fl32xx_priv *priv);
+static int is31fl3216_software_shutdown(struct is31fl32xx_priv *priv,
+ bool enable);
+static const struct is31fl32xx_chipdef is31fl3216_cdef = {
+ .channels = 16,
+ .shutdown_reg = IS31FL32XX_REG_NONE,
+ .pwm_update_reg = 0xB0,
+ .global_control_reg = IS31FL32XX_REG_NONE,
+ .reset_reg = IS31FL32XX_REG_NONE,
+ .pwm_register_base = 0x10,
+ .pwm_registers_reversed = true,
+ .led_control_register_base = 0x01,
+ .enable_bits_per_led_control_register = 8,
+ .reset_func = is31fl3216_reset,
+ .sw_shutdown_func = is31fl3216_software_shutdown,
+};
+
+static int is31fl32xx_write(struct is31fl32xx_priv *priv, u8 reg, u8 val)
+{
+ int ret;
+
+ dev_dbg(&priv->client->dev, "writing register 0x%02X=0x%02X", reg, val);
+
+ ret = i2c_smbus_write_byte_data(priv->client, reg, val);
+ if (ret) {
+ dev_err(&priv->client->dev,
+ "register write to 0x%02X failed (error %d)",
+ reg, ret);
+ }
+ return ret;
+}
+
+/*
+ * Custom reset function for IS31FL3216 because it does not have a RESET
+ * register the way that the other IS31FL32xx chips do. We don't bother
+ * writing the GPIO and animation registers, because the registers we
+ * do write ensure those will have no effect.
+ */
+static int is31fl3216_reset(struct is31fl32xx_priv *priv)
+{
+ unsigned int i;
+ int ret;
+
+ ret = is31fl32xx_write(priv, IS31FL3216_CONFIG_REG,
+ IS31FL3216_CONFIG_SSD_ENABLE);
+ if (ret)
+ return ret;
+ for (i = 0; i < priv->cdef->channels; i++) {
+ ret = is31fl32xx_write(priv, priv->cdef->pwm_register_base+i,
+ 0x00);
+ if (ret)
+ return ret;
+ }
+ ret = is31fl32xx_write(priv, priv->cdef->pwm_update_reg, 0);
+ if (ret)
+ return ret;
+ ret = is31fl32xx_write(priv, IS31FL3216_LIGHTING_EFFECT_REG, 0x00);
+ if (ret)
+ return ret;
+ ret = is31fl32xx_write(priv, IS31FL3216_CHANNEL_CONFIG_REG, 0x00);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+/*
+ * Custom Software-Shutdown function for IS31FL3216 because it does not have
+ * a SHUTDOWN register the way that the other IS31FL32xx chips do.
+ * We don't bother doing a read/modify/write on the CONFIG register because
+ * we only ever use a value of '0' for the other fields in that register.
+ */
+static int is31fl3216_software_shutdown(struct is31fl32xx_priv *priv,
+ bool enable)
+{
+ u8 value = enable ? IS31FL3216_CONFIG_SSD_ENABLE :
+ IS31FL3216_CONFIG_SSD_DISABLE;
+
+ return is31fl32xx_write(priv, IS31FL3216_CONFIG_REG, value);
+}
+
+/*
+ * NOTE: A mutex is not needed in this function because:
+ * - All referenced data is read-only after probe()
+ * - The I2C core has a mutex on to protect the bus
+ * - There are no read/modify/write operations
+ * - Intervening operations between the write of the PWM register
+ * and the Update register are harmless.
+ *
+ * Example:
+ * PWM_REG_1 write 16
+ * UPDATE_REG write 0
+ * PWM_REG_2 write 128
+ * UPDATE_REG write 0
+ * vs:
+ * PWM_REG_1 write 16
+ * PWM_REG_2 write 128
+ * UPDATE_REG write 0
+ * UPDATE_REG write 0
+ * are equivalent. Poking the Update register merely applies all PWM
+ * register writes up to that point.
+ */
+static int is31fl32xx_brightness_set(struct led_classdev *led_cdev,
+ enum led_brightness brightness)
+{
+ const struct is31fl32xx_led_data *led_data =
+ container_of(led_cdev, struct is31fl32xx_led_data, cdev);
+ const struct is31fl32xx_chipdef *cdef = led_data->priv->cdef;
+ u8 pwm_register_offset;
+ int ret;
+
+ dev_dbg(led_cdev->dev, "%s: %d\n", __func__, brightness);
+
+ /* NOTE: led_data->channel is 1-based */
+ if (cdef->pwm_registers_reversed)
+ pwm_register_offset = cdef->channels - led_data->channel;
+ else
+ pwm_register_offset = led_data->channel - 1;
+
+ ret = is31fl32xx_write(led_data->priv,
+ cdef->pwm_register_base + pwm_register_offset,
+ brightness);
+ if (ret)
+ return ret;
+
+ return is31fl32xx_write(led_data->priv, cdef->pwm_update_reg, 0);
+}
+
+static int is31fl32xx_reset_regs(struct is31fl32xx_priv *priv)
+{
+ const struct is31fl32xx_chipdef *cdef = priv->cdef;
+ int ret;
+
+ if (cdef->reset_reg != IS31FL32XX_REG_NONE) {
+ ret = is31fl32xx_write(priv, cdef->reset_reg, 0);
+ if (ret)
+ return ret;
+ }
+
+ if (cdef->reset_func)
+ return cdef->reset_func(priv);
+
+ return 0;
+}
+
+static int is31fl32xx_software_shutdown(struct is31fl32xx_priv *priv,
+ bool enable)
+{
+ const struct is31fl32xx_chipdef *cdef = priv->cdef;
+ int ret;
+
+ if (cdef->shutdown_reg != IS31FL32XX_REG_NONE) {
+ u8 value = enable ? IS31FL32XX_SHUTDOWN_SSD_ENABLE :
+ IS31FL32XX_SHUTDOWN_SSD_DISABLE;
+ ret = is31fl32xx_write(priv, cdef->shutdown_reg, value);
+ if (ret)
+ return ret;
+ }
+
+ if (cdef->sw_shutdown_func)
+ return cdef->sw_shutdown_func(priv, enable);
