LM3532 has 3 backlight strings and 8 bit dimming is supported.
PWM brightness control is also supported.
Common backlight driver is controlled by TI LMU backlight driver.
Only LM3532 specific code is implemented here.
Cc: Jingoo Han <jg1.han@xxxxxxxxxxx>
Cc: Bryan Wu <cooloney@xxxxxxxxx>
Cc: Lee Jones <lee.jones@xxxxxxxxxx>
Signed-off-by: Milo Kim <milo.kim@xxxxxx>
---
drivers/video/backlight/Kconfig | 9 ++
drivers/video/backlight/Makefile | 1 +
drivers/video/backlight/lm3532_bl.c | 240 +++++++++++++++++++++++++++++++++++
3 files changed, 250 insertions(+)
create mode 100644 drivers/video/backlight/lm3532_bl.c
diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig
index 3641698..d841057 100644
--- a/drivers/video/backlight/Kconfig
+++ b/drivers/video/backlight/Kconfig
@@ -384,6 +384,15 @@ config BACKLIGHT_LM3639
help
This supports TI LM3639 Backlight + 1.5A Flash LED Driver
+config BACKLIGHT_LM3532
+ tristate "Backlight driver for TI LM3532"
+ depends on BACKLIGHT_CLASS_DEVICE && MFD_TI_LMU
+ select TI_LMU_BACKLIGHT
+ help
+ Say Y to enable the backlight driver for TI LM3532.
+ Up to 3 backlight strings and 8 bit dimming is supported.
+ PWM brightness control is also supported.
+
config TI_LMU_BACKLIGHT
tristate "Backlight driver for TI LMU"
depends on BACKLIGHT_LM3532 || BACKLIGHT_LM3631 || BACKLIGHT_LM3633 || BACKLIGHT_LM3695 || BACKLIGHT_LM3697
diff --git a/drivers/video/backlight/Makefile b/drivers/video/backlight/Makefile
index f80e046..51354d1 100644
--- a/drivers/video/backlight/Makefile
+++ b/drivers/video/backlight/Makefile
@@ -39,6 +39,7 @@ obj-$(CONFIG_BACKLIGHT_HP700) += jornada720_bl.o
obj-$(CONFIG_BACKLIGHT_LM3533) += lm3533_bl.o
obj-$(CONFIG_BACKLIGHT_LM3630A) += lm3630a_bl.o
obj-$(CONFIG_BACKLIGHT_LM3639) += lm3639_bl.o
+obj-$(CONFIG_BACKLIGHT_LM3532) += lm3532_bl.o
obj-$(CONFIG_TI_LMU_BACKLIGHT) += ti-lmu-backlight.o
obj-$(CONFIG_BACKLIGHT_LOCOMO) += locomolcd.o
obj-$(CONFIG_BACKLIGHT_LP855X) += lp855x_bl.o
diff --git a/drivers/video/backlight/lm3532_bl.c b/drivers/video/backlight/lm3532_bl.c
new file mode 100644
index 0000000..c4cf636
--- /dev/null
+++ b/drivers/video/backlight/lm3532_bl.c
@@ -0,0 +1,240 @@
+/*
+ * TI LM3532 Backlight Driver
+ *
+ * Copyright 2014 Texas Instruments
+ *
+ * Author: Milo Kim <milo.kim@xxxxxx>
+ *
+ * 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.
+ *
+ * LM3532 backlight driver consists of three parts
+ *
+ * 1) LM3532 chip specific part: this file
+ * Define device specific operations
+ * Register LMU backlight driver
+ *
+ * 2) LMU backlight common driver: ti-lmu-backlight
+ * General backlight subsystem control
+ *
+ * 3) LMU effect driver
+ * Backlight ramp time configuration
+ *
+ */
+
+#include <linux/backlight.h>
+#include <linux/err.h>
+#include <linux/mfd/ti-lmu.h>
+#include <linux/mfd/ti-lmu-effect.h>
+#include <linux/mfd/ti-lmu-register.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+#include <linux/slab.h>
+
+#include "ti-lmu-backlight.h"
+
+#define LM3532_PWM1 0
+#define LM3532_PWM2 1
+#define LM3532_BL_MAX_STRINGS 3
+#define LM3532_MAX_ZONE_CFG 3
+#define LM3532_MAX_BRIGHTNESS 255
+
+static int lm3532_bl_init(struct ti_lmu_bl_chip *chip)
+{
+ int i, ret;
+ u8 lm3532_regs[] = { LM3532_REG_ZONE_CFG_A, LM3532_REG_ZONE_CFG_B,
+ LM3532_REG_ZONE_CFG_C, };
+
+ /*
+ * Assign zone targets as below.
+ * Zone target 0 for control A
+ * Zone target 1 for control B
+ * Zone target 2 for control C
+ */
+
+ for (i = 0; i < LM3532_MAX_ZONE_CFG; i++) {
+ ret = ti_lmu_update_bits(chip->lmu, lm3532_regs[i],
+ LM3532_ZONE_CFG_MASK,
+ i << LM3532_ZONE_CFG_SHIFT);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+static int lm3532_bl_enable(struct ti_lmu_bl *lmu_bl, int enable)
+{
+ return ti_lmu_update_bits(lmu_bl->chip->lmu, LM3532_REG_ENABLE,
+ BIT(lmu_bl->bank_id),
+ enable << lmu_bl->bank_id);
+}
+
+static int lm3532_bl_set_brightness(struct ti_lmu_bl *lmu_bl, int brightness)
+{
+ u8 reg[] = { LM3532_REG_BRT_A, LM3532_REG_BRT_B, LM3532_REG_BRT_C, };
+
+ return ti_lmu_write_byte(lmu_bl->chip->lmu, reg[lmu_bl->bank_id],
+ brightness);
+}
+
+static int lm3532_bl_select_pwm_bank(struct ti_lmu_bl *lmu_bl, int bank_id)
+{
+ struct ti_lmu *lmu = lmu_bl->chip->lmu;
+ static int num_pwms;
+ u8 pwm_sel;
+ u8 mask[] = { LM3532_PWM_SEL_A_MASK, LM3532_PWM_SEL_B_MASK,
+ LM3532_PWM_SEL_C_MASK, };
+ u8 shift[] = { LM3532_PWM_SEL_A_SHIFT, LM3532_PWM_SEL_B_SHIFT,
+ LM3532_PWM_SEL_C_SHIFT, };
+
+ if (num_pwms > 0)
+ pwm_sel = LM3532_PWM2;
+ else
+ pwm_sel = LM3532_PWM1;
+
+ num_pwms++;
+
+ snprintf(lmu_bl->pwm_name, sizeof(lmu_bl->pwm_name), "%s:%d",
+ LMU_BL_DEFAULT_PWM_NAME, pwm_sel);
+
+ return ti_lmu_update_bits(lmu, LM3532_REG_PWM_CFG_BASE + bank_id,
+ mask[bank_id],
+ (1 << shift[bank_id]) | pwm_sel);
+}
+
+static int lm3532_bl_string_configure(struct ti_lmu_bl *lmu_bl)
+{
+ struct ti_lmu *lmu = lmu_bl->chip->lmu;
+ int bank_id = lmu_bl->bank_id;
+ int is_detected = 0;
+ int i, ret;
+ u8 mask[] = { LM3532_ILED1_CFG_MASK, LM3532_ILED2_CFG_MASK,
+ LM3532_ILED3_CFG_MASK, };
+ u8 shift[] = { LM3532_ILED1_CFG_SHIFT, LM3532_ILED2_CFG_SHIFT,
+ LM3532_ILED3_CFG_SHIFT, };
+
+ /* Assign control bank from backlight string configuration */
+ for (i = 0; i < LM3532_BL_MAX_STRINGS; i++) {
+ if (test_bit(i, &lmu_bl->bl_pdata->bl_string)) {
+ ret = ti_lmu_update_bits(lmu, LM3532_REG_OUTPUT_CFG,
+ mask[i], bank_id << shift[i]);
+ if (ret)
+ return ret;
+
+ is_detected = 1;
+ }
+ }
+
+ if (!is_detected) {
+ dev_err(lmu_bl->chip->dev, "No backlight string found\n");
+ return -EINVAL;
+ }
+
+ if (lmu_bl->mode == BL_PWM_BASED)
+ return lm3532_bl_select_pwm_bank(lmu_bl, bank_id);
+
+ return 0;
+}
+
+static int lm3532_bl_set_current(struct ti_lmu_bl *lmu_bl)
+{
+ u8 reg[] = { LM3532_REG_IMAX_A, LM3532_REG_IMAX_B, LM3532_REG_IMAX_C };
+
+ return ti_lmu_write_byte(lmu_bl->chip->lmu, reg[lmu_bl->bank_id],
+ lmu_bl->bl_pdata->imax);
+}
+
+static void lm3532_bl_effect_request(struct ti_lmu_bl *lmu_bl)
+{
+ int i;
+ const char *name[] = {
+ [BL_EFFECT_RAMPUP] = LM3532_EFFECT_RAMPUP,
+ [BL_EFFECT_RAMPDN] = LM3532_EFFECT_RAMPDOWN,
+ };
+
+ for (i = BL_EFFECT_RAMPUP; i <= BL_EFFECT_RAMPDN; i++)
+ ti_lmu_effect_request(name[i],
+ ti_lmu_backlight_effect_callback,
+ i, lmu_bl);
+}
+
+static int lm3532_bl_configure(struct ti_lmu_bl *lmu_bl)
+{
+ int ret;
+
+ ret = lm3532_bl_string_configure(lmu_bl);
+ if (ret)
+ return ret;
+
+ ret = lm3532_bl_set_current(lmu_bl);
+ if (ret)
+ return ret;
+
+ /* LMU effect is optional, checking return value is not required */
+ lm3532_bl_effect_request(lmu_bl);
+
+ return 0;
+}
+
+static const struct ti_lmu_bl_ops lm3532_lmu_ops = {
+ .init = lm3532_bl_init,
+ .configure = lm3532_bl_configure,
+ .update_brightness = lm3532_bl_set_brightness,
+ .bl_enable = lm3532_bl_enable,
+ .max_brightness = LM3532_MAX_BRIGHTNESS,
+};
+
+static int lm3532_bl_probe(struct platform_device *pdev)
+{
+ struct ti_lmu *lmu = dev_get_drvdata(pdev->dev.parent);
+ struct ti_lmu_bl_chip *chip;
+ struct ti_lmu_bl *lmu_bl;
+
+ chip = ti_lmu_backlight_init_device(&pdev->dev, lmu, &lm3532_lmu_ops);
+ if (IS_ERR(chip))
+ return PTR_ERR(chip);
+
+ lmu_bl = ti_lmu_backlight_register(chip, lmu->pdata->bl_pdata,
+ lmu->pdata->num_backlights);
+ if (IS_ERR(lmu_bl))
+ return PTR_ERR(lmu_bl);
+
+ platform_set_drvdata(pdev, lmu_bl);
+
+ return 0;
+}
+
+static int lm3532_bl_remove(struct platform_device *pdev)
+{
+ struct ti_lmu_bl *lmu_bl = platform_get_drvdata(pdev);
+
+ return ti_lmu_backlight_unregister(lmu_bl);
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id lm3532_bl_of_match[] = {
+ { .compatible = "ti,lm3532-backlight", },
+ { }
+};
+MODULE_DEVICE_TABLE(of, lm3532_bl_of_match);
+#endif
+
+static struct platform_driver lm3532_bl_driver = {
+ .probe = lm3532_bl_probe,
+ .remove = lm3532_bl_remove,
+ .driver = {
+ .name = "lm3532-backlight",
+ .owner = THIS_MODULE,
+ .of_match_table = of_match_ptr(lm3532_bl_of_match),
+ },
+};
+module_platform_driver(lm3532_bl_driver);
+
+MODULE_DESCRIPTION("TI LM3532 Backlight Driver");
+MODULE_AUTHOR("Milo Kim");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:lm3532-backlight");
--
1.7.9.5
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