The TLC5925 is a 16-channels constant-current LED sink driver. It is controlled via SPI but doesn't offer a register-based interface. Instead it contains a shift register and latches that convert the serial input into a parallel output. Signed-off-by: Jean-Jacques Hiblot <jjhiblot@xxxxxxxxxxxxxxx> --- drivers/leds/Kconfig | 6 ++ drivers/leds/Makefile | 1 + drivers/leds/leds-tlc5925.c | 157 ++++++++++++++++++++++++++++++++++++ 3 files changed, 164 insertions(+) create mode 100644 drivers/leds/leds-tlc5925.c diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig index a49979f41eee..b17eb01210ba 100644 --- a/drivers/leds/Kconfig +++ b/drivers/leds/Kconfig @@ -658,6 +658,12 @@ config LEDS_TLC591XX This option enables support for Texas Instruments TLC59108 and TLC59116 LED controllers. +config LEDS_TLC5925 + tristate "LED driver for TLC5925 controller" + depends on LEDS_CLASS && SPI + help + This option enables support for Texas Instruments TLC5925. + config LEDS_MAX77650 tristate "LED support for Maxim MAX77650 PMIC" depends on LEDS_CLASS && MFD_MAX77650 diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile index 4fd2f92cd198..9d15b88d482f 100644 --- a/drivers/leds/Makefile +++ b/drivers/leds/Makefile @@ -81,6 +81,7 @@ obj-$(CONFIG_LEDS_SYSCON) += leds-syscon.o obj-$(CONFIG_LEDS_TCA6507) += leds-tca6507.o obj-$(CONFIG_LEDS_TI_LMU_COMMON) += leds-ti-lmu-common.o obj-$(CONFIG_LEDS_TLC591XX) += leds-tlc591xx.o +obj-$(CONFIG_LEDS_TLC5925) += leds-tlc5925.o obj-$(CONFIG_LEDS_TPS6105X) += leds-tps6105x.o obj-$(CONFIG_LEDS_TURRIS_OMNIA) += leds-turris-omnia.o obj-$(CONFIG_LEDS_WM831X_STATUS) += leds-wm831x-status.o diff --git a/drivers/leds/leds-tlc5925.c b/drivers/leds/leds-tlc5925.c new file mode 100644 index 000000000000..f33eff8b7333 --- /dev/null +++ b/drivers/leds/leds-tlc5925.c @@ -0,0 +1,157 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * The driver supports controllers with a very simple SPI protocol: + * - the data is deserialized in a shift-register when CS is asserted + * - the data is latched when CS is de-asserted + * - the LED are either on or off (no control of the brightness) + * + * Supported devices: + * - "ti,tlc5925": Low-Power 16-Channel Constant-Current LED Sink Driver + * https://www.ti.com/lit/ds/symlink/tlc5925.pdf + */ + +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/leds.h> +#include <linux/err.h> +#include <linux/spi/spi.h> +#include <linux/property.h> +#include <linux/workqueue.h> + +struct single_led_priv { + int idx; + struct led_classdev cdev; +}; + +struct tlc5925_leds_priv { + int max_num_leds; + u8 *state; + spinlock_t lock; + struct single_led_priv leds[]; +}; + +static int tlc5925_brightness_set_blocking(struct led_classdev *cdev, + enum led_brightness brightness) +{ + struct spi_device *spi = to_spi_device(cdev->dev->parent); + struct tlc5925_leds_priv *priv = spi_get_drvdata(spi); + struct single_led_priv *led = container_of(cdev, + struct single_led_priv, + cdev); + int index = led->idx; + + spin_lock(&priv->lock); + if (brightness) + priv->state[index / 8] |= (1 << (index % 8)); + else + priv->state[index / 8] &= ~(1 << (index % 8)); + spin_unlock(&priv->lock); + + return spi_write(spi, priv->state, priv->max_num_leds / 8); +} + + +static int tlc5925_probe(struct spi_device *spi) +{ + struct device *dev = &spi->dev; + struct fwnode_handle *child; + struct tlc5925_leds_priv *priv; + int ret; + int max_num_leds, count; + struct gpio_descs *gpios; + + count = device_get_child_node_count(dev); + if (!count) { + dev_err(dev, "no led defined.\n"); + return -ENODEV; + } + + ret = device_property_read_u32_array(dev, "shift_register_length", + &max_num_leds, 1); + if (ret) { + dev_err(dev, "'shift_register_length' property is required.\n"); + return -EINVAL; + } + + if (max_num_leds % 8) { + dev_err(dev, "'shift_register_length' must be a multiple of 8\n"); + return -EINVAL; + } + + if (max_num_leds == 0) { + dev_err(dev, "'shift_register_length' must be greater than 0\n"); + return -EINVAL; + } + + /* Assert all the OE/ lines */ + gpios = devm_gpiod_get_array(dev, "output-enable-b", GPIOD_OUT_LOW); + if (IS_ERR(gpios)) { + dev_err(dev, "Unable to get the 'output-enable-b' gpios\n"); + return PTR_ERR(gpios); + } + + priv = devm_kzalloc(dev, struct_size(priv, leds, count), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + spin_lock_init(&priv->lock); + + priv->state = devm_kzalloc(dev, DIV_ROUND_UP(max_num_leds, 8), GFP_KERNEL); + if (!priv->state) + return -ENOMEM; + + priv->max_num_leds = max_num_leds; + + device_for_each_child_node(dev, child) { + struct led_init_data init_data = {.fwnode = child}; + struct led_classdev *cdev; + u32 idx; + + ret = fwnode_property_read_u32_array(child, "reg", &idx, 1); + if (ret || idx >= max_num_leds) { + dev_err(dev, "%s: invalid reg value. Ignoring.\n", + fwnode_get_name(child)); + fwnode_handle_put(child); + continue; + } + + count--; + priv->leds[count].idx = idx; + cdev = &(priv->leds[count].cdev); + cdev->brightness = LED_OFF; + cdev->max_brightness = 1; + cdev->brightness_set_blocking = tlc5925_brightness_set_blocking; + + ret = devm_led_classdev_register_ext(dev, cdev, &init_data); + if (ret) { + dev_err(dev, "%s: cannot create LED device.\n", + fwnode_get_name(child)); + fwnode_handle_put(child); + continue; + } + } + + spi_set_drvdata(spi, priv); + + return 0; +} + +static const struct of_device_id tlc5925_dt_ids[] = { + { .compatible = "ti,tlc5925", }, + {}, +}; + +static struct spi_driver tlc5925_driver = { + .probe = tlc5925_probe, + .driver = { + .name = KBUILD_MODNAME, + .of_match_table = tlc5925_dt_ids, + }, +}; + +module_spi_driver(tlc5925_driver); + +MODULE_AUTHOR("Jean-Jacques Hiblot <jjhiblot@xxxxxxxxxxxxxxx>"); +MODULE_DESCRIPTION("TLC5925 LED driver"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("spi:tlc5925"); -- 2.25.1
