4 files changed, 213 insertions, 0 deletions

diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index 71be87bdb926..4e262696be19 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -783,6 +783,15 @@ config LEDS_NIC78BX
           To compile this driver as a module, choose M here: the module
           will be called leds-nic78bx.
 
+config LEDS_TI_LMU_COMMON
+        tristate "LED driver for TI LMU"
+        depends on LEDS_CLASS
+        depends on REGMAP
+        help
+          Say Y to enable the LED driver for TI LMU devices.
+          This supports common features between the TI LM3532, LM3631, LM3632,
+          LM3633, LM3695 and LM3697.
+
 comment "LED Triggers"
 source "drivers/leds/trigger/Kconfig"
 
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index 1e9702ebffee..84c49339a8e3 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -81,6 +81,7 @@ obj-$(CONFIG_LEDS_MT6323)		+= leds-mt6323.o
 obj-$(CONFIG_LEDS_LM3692X)              += leds-lm3692x.o
 obj-$(CONFIG_LEDS_SC27XX_BLTC)          += leds-sc27xx-bltc.o
 obj-$(CONFIG_LEDS_LM3601X)              += leds-lm3601x.o
+obj-$(CONFIG_LEDS_TI_LMU_COMMON)        += leds-ti-lmu-common.o
 
 # LED SPI Drivers
 obj-$(CONFIG_LEDS_CR0014114)            += leds-cr0014114.o
diff --git a/drivers/leds/leds-ti-lmu-common.c b/drivers/leds/leds-ti-lmu-common.c
new file mode 100644
index 000000000000..adc7293004f1
--- /dev/null
+++ b/drivers/leds/leds-ti-lmu-common.c
@@ -0,0 +1,156 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright 2015 Texas Instruments
+// Copyright 2018 Sebastian Reichel
+// Copyright 2018 Pavel Machek <pavel@ucw.cz>
+// TI LMU LED common framework, based on previous work from
+// Milo Kim <milo.kim@ti.com>
+
+#include <linux/bitops.h>
+#include <linux/err.h>
+#include <linux/of_device.h>
+
+#include <linux/leds-ti-lmu-common.h>
+
+const static int ramp_table[16] = {2048, 262000, 524000, 1049000, 2090000,
+                                4194000, 8389000, 16780000, 33550000, 41940000,
+                                50330000, 58720000, 67110000, 83880000,
+                                100660000, 117440000};
+
+static int ti_lmu_common_update_brightness(struct ti_lmu_bank *lmu_bank,
+                                           int brightness)
+{
+        struct regmap *regmap = lmu_bank->regmap;
+        u8 reg, val;
+        int ret;
+
+        /*
+         * Brightness register update
+         *
+         * 11 bit dimming: update LSB bits and write MSB byte.
+         *                 MSB brightness should be shifted.
+         *  8 bit dimming: write MSB byte.
+         */
+        if (lmu_bank->max_brightness == MAX_BRIGHTNESS_11BIT) {
+                reg = lmu_bank->lsb_brightness_reg;
+                ret = regmap_update_bits(regmap, reg,
+                                         LMU_11BIT_LSB_MASK,
+                                         brightness);
+                if (ret)
+                        return ret;
+
+                val = brightness >> LMU_11BIT_MSB_SHIFT;
+        } else {
+                val = brightness;
+        }
+
+        reg = lmu_bank->msb_brightness_reg;
+
+        return regmap_write(regmap, reg, val);
+}
+
+int ti_lmu_common_set_brightness(struct ti_lmu_bank *lmu_bank, int brightness)
+{
+        return ti_lmu_common_update_brightness(lmu_bank, brightness);
+}
+EXPORT_SYMBOL(ti_lmu_common_set_brightness);
+
+static int ti_lmu_common_convert_ramp_to_index(unsigned int usec)
+{
+        int size = ARRAY_SIZE(ramp_table);
+        int i;
+
+        if (usec <= ramp_table[0])
+                return 0;
+
+        if (usec > ramp_table[size - 1])
+                return size - 1;
+
+        for (i = 1; i < size; i++) {
+                if (usec == ramp_table[i])
+                        return i;
+
+                /* Find an approximate index by looking up the table */
+                if (usec > ramp_table[i - 1] && usec < ramp_table[i]) {
+                        if (usec - ramp_table[i - 1] < ramp_table[i] - usec)
+                                return i - 1;
+                        else
+                                return i;
+                }
+        }
+
+        return -EINVAL;
+}
+
+int ti_lmu_common_set_ramp(struct ti_lmu_bank *lmu_bank)
+{
+        struct regmap *regmap = lmu_bank->regmap;
+        u8 ramp, ramp_up, ramp_down;
+
+        if (lmu_bank->ramp_up_usec == 0 && lmu_bank->ramp_down_usec == 0) {
+                ramp_up = 0;
+                ramp_down = 0;
+        } else {
+                ramp_up = ti_lmu_common_convert_ramp_to_index(lmu_bank->ramp_up_usec);
+                ramp_down = ti_lmu_common_convert_ramp_to_index(lmu_bank->ramp_down_usec);
+        }
+
+        if (ramp_up < 0 || ramp_down < 0)
+                return -EINVAL;
+
+        ramp = (ramp_up << 4) | ramp_down;
+
+        return regmap_write(regmap, lmu_bank->runtime_ramp_reg, ramp);
+
+}
+EXPORT_SYMBOL(ti_lmu_common_set_ramp);
+
+int ti_lmu_common_get_ramp_params(struct device *dev,
+                                  struct fwnode_handle *child,
+                                  struct ti_lmu_bank *lmu_data)
+{
+        int ret;
+
+        ret = fwnode_property_read_u32(child, "ramp-up-us",
+                                 &lmu_data->ramp_up_usec);
+        if (ret)
+                dev_warn(dev, "ramp-up-us property missing\n");
+
+
+        ret = fwnode_property_read_u32(child, "ramp-down-us",
+                                 &lmu_data->ramp_down_usec);
+        if (ret)
+                dev_warn(dev, "ramp-down-us property missing\n");
+
+        return 0;
+}
+EXPORT_SYMBOL(ti_lmu_common_get_ramp_params);
+
+int ti_lmu_common_get_brt_res(struct device *dev, struct fwnode_handle *child,
+                                  struct ti_lmu_bank *lmu_data)
+{
+        int ret;
+
+        ret = device_property_read_u32(dev, "ti,brightness-resolution",
+                                       &lmu_data->max_brightness);
+        if (ret)
+                ret = fwnode_property_read_u32(child,
+                                               "ti,brightness-resolution",
+                                               &lmu_data->max_brightness);
+        if (lmu_data->max_brightness <= 0) {
+                lmu_data->max_brightness = MAX_BRIGHTNESS_8BIT;
+                return ret;
+        }
+
+        if (lmu_data->max_brightness > MAX_BRIGHTNESS_11BIT)
+                        lmu_data->max_brightness = MAX_BRIGHTNESS_11BIT;
+
+
+        return 0;
+}
+EXPORT_SYMBOL(ti_lmu_common_get_brt_res);
+
+MODULE_DESCRIPTION("TI LMU common LED framework");
+MODULE_AUTHOR("Sebastian Reichel");
+MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("ti-lmu-led-common");
diff --git a/include/linux/leds-ti-lmu-common.h b/include/linux/leds-ti-lmu-common.h
new file mode 100644
index 000000000000..5eb111f38803
--- /dev/null
+++ b/include/linux/leds-ti-lmu-common.h
@@ -0,0 +1,47 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// TI LMU Common Core
+// Copyright (C) 2018 Texas Instruments Incorporated - http://www.ti.com/
+
+#ifndef _TI_LMU_COMMON_H_
+#define _TI_LMU_COMMON_H_
+
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/init.h>
+#include <linux/leds.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <uapi/linux/uleds.h>
+
+#define LMU_11BIT_LSB_MASK      (BIT(0) | BIT(1) | BIT(2))
+#define LMU_11BIT_MSB_SHIFT     3
+
+#define MAX_BRIGHTNESS_8BIT     255
+#define MAX_BRIGHTNESS_11BIT    2047
+
+struct ti_lmu_bank {
+        struct regmap *regmap;
+
+        int max_brightness;
+
+        u8 lsb_brightness_reg;
+        u8 msb_brightness_reg;
+
+        u8 runtime_ramp_reg;
+        u32 ramp_up_usec;
+        u32 ramp_down_usec;
+};
+
+int ti_lmu_common_set_brightness(struct ti_lmu_bank *lmu_bank, int brightness);
+
+int ti_lmu_common_set_ramp(struct ti_lmu_bank *lmu_bank);
+
+int ti_lmu_common_get_ramp_params(struct device *dev,
+                                  struct fwnode_handle *child,
+                                  struct ti_lmu_bank *lmu_data);
+
+int ti_lmu_common_get_brt_res(struct device *dev, struct fwnode_handle *child,
+                              struct ti_lmu_bank *lmu_data);
+
+#endif /* _TI_LMU_COMMON_H_ */