[RFC,v2,1/9] leds: add TI LMU backlight driver

Message ID	20180928182954.25446-2-dmurphy@ti.com (mailing list archive)
State	New, archived
Headers	show Return-Path: <linux-omap-owner@kernel.org> From: Dan Murphy <dmurphy@ti.com> To: <robh+dt@kernel.org>, <jacek.anaszewski@gmail.com>, <pavel@ucw.cz> CC: <devicetree@vger.kernel.org>, <linux-kernel@vger.kernel.org>, <lee.jones@linaro.org>, <linux-omap@vger.kernel.org>, <linux-leds@vger.kernel.org>, Milo Kim <milo.kim@ti.com>, Sebastian Reichel <sebastian.reichel@collabora.co.uk> Subject: [RFC PATCH v2 1/9] leds: add TI LMU backlight driver Date: Fri, 28 Sep 2018 13:29:46 -0500 Message-ID: <20180928182954.25446-2-dmurphy@ti.com> In-Reply-To: <20180928182954.25446-1-dmurphy@ti.com> References: <20180928182954.25446-1-dmurphy@ti.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-omap-owner@vger.kernel.org Precedence: bulk
Series	TI LMU and Dedicated Drivers \| expand [RFC,v2,0/9] TI LMU and Dedicated Drivers [RFC,v2,1/9] leds: add TI LMU backlight driver [RFC,v2,2/9] dt-bindings: ti-lmu: Remove LM3697 [RFC,v2,3/9] mfd: ti-lmu: Remove support for LM3697 [RFC,v2,4/9] dt-bindings: leds: Add bindings for lm3697 driver [RFC,v2,5/9] leds: lm3697: Introduce the lm3697 driver [RFC,v2,6/9] dt-bindings: leds: Add support for the LM3633 [RFC,v2,7/9] leds: lm3633: Introduce the lm3633 driver [RFC,v2,8/9] dt-bindings: leds: Add the LM3632 LED dt binding [RFC,v2,9/9] leds: lm3632: Introduce the TI LM3632 driver

diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig index 44097a3e0fcc..dc717b30d9d3 100644 --- a/drivers/leds/Kconfig +++ b/drivers/leds/Kconfig @@ -756,6 +756,14 @@ 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 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 420b5d2cfa62..e09bb27bc7ea 100644 --- a/drivers/leds/Makefile +++ b/drivers/leds/Makefile @@ -78,6 +78,7 @@ 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-$(CONFIG_LEDS_TI_LMU_COMMON) += ti-lmu-led-common.o # LED SPI Drivers obj-$(CONFIG_LEDS_CR0014114) += leds-cr0014114.o diff --git a/drivers/leds/ti-lmu-led-common.c b/drivers/leds/ti-lmu-led-common.c new file mode 100644 index 000000000000..2d4f22f480d1 --- /dev/null +++ b/drivers/leds/ti-lmu-led-common.c @@ -0,0 +1,138 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright 2015 Texas Instruments + * Copyright 2018 Sebastian Reichel + * Copyright 2018 Pavel Machek <pavel@ucw.cz> + * + * TI LMU Led driver, based on previous work from + * Milo Kim <milo.kim@ti.com> + */ + +#include <linux/bitops.h> +#include <linux/err.h> +#include <linux/notifier.h> +#include <linux/of_device.h> +#include <linux/platform_device.h> + +#include "ti-lmu-led-common.h" + +const static int ramp_table[16] = { 2, 262, 524, 1049, 2090, 4194, 8389, + 16780, 33550, 41940, 50330, 58720, + 67110, 83880, 100660, 117440}; + +static int ti_lmu_common_update_brightness_register(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) +{ + lmu_bank->current_brightness = brightness; + + return ti_lmu_common_update_brightness_register(lmu_bank, brightness); +} +EXPORT_SYMBOL(ti_lmu_common_set_brightness); + +static int ti_lmu_common_convert_ramp_to_index(unsigned int msec) +{ + int size = ARRAY_SIZE(ramp_table); + int i; + + if (msec <= ramp_table[0]) + return 0; + + if (msec > ramp_table[size - 1]) + return size - 1; + + for (i = 1; i < size; i++) { + if (msec == ramp_table[i]) + return i; + + /* Find an approximate index by looking up the table */ + if (msec > ramp_table[i - 1] && msec < ramp_table[i]) { + if (msec - ramp_table[i - 1] < ramp_table[i] - msec) + 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_msec == 0 && lmu_bank->ramp_down_msec == 0) { + ramp_up = 0; + ramp_down = 0; + } else { + ramp_up = ti_lmu_common_convert_ramp_to_index(lmu_bank->ramp_up_msec); + ramp_down = ti_lmu_common_convert_ramp_to_index(lmu_bank->ramp_down_msec); + } + + 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-ms", + &lmu_data->ramp_up_msec); + if (ret) + dev_warn(dev, "ramp-up-ms property missing\n"); + + + ret = fwnode_property_read_u32(child, "ramp-down-ms", + &lmu_data->ramp_down_msec); + if (ret) + dev_warn(dev, "ramp-down-ms property missing\n"); + + return 0; +} +EXPORT_SYMBOL(ti_lmu_common_get_ramp_params); + +MODULE_DESCRIPTION("TI LMU LED Driver"); +MODULE_AUTHOR("Sebastian Reichel"); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS("platform:ti-lmu-led"); diff --git a/drivers/leds/ti-lmu-led-common.h b/drivers/leds/ti-lmu-led-common.h new file mode 100644 index 000000000000..511768dd54b6 --- /dev/null +++ b/drivers/leds/ti-lmu-led-common.h @@ -0,0 +1,54 @@ +// SPDX-License-Identifier: GPL-2.0 +// TI LMU Common Core +// Copyright (C) 2018 Texas Instruments Incorporated - http://www.ti.com/ + +#include <linux/delay.h> +#include <linux/device.h> +#include <linux/i2c.h> +#include <linux/init.h> +#include <linux/leds.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/regmap.h> +#include <linux/slab.h> +#include <uapi/linux/uleds.h> + +#define LMU_DUAL_CHANNEL_USED (BIT(0) | BIT(1)) +#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 + +#define NUM_DUAL_CHANNEL 2 + +struct ti_lmu_bank { + struct regmap *regmap; + + int bank_id; + int fault_monitor_used; + + u8 enable_reg; + unsigned long enable_usec; + + int current_brightness; + u32 default_brightness; + int max_brightness; + + u8 lsb_brightness_reg; + u8 msb_brightness_reg; + + u8 runtime_ramp_reg; + u32 ramp_up_msec; + u32 ramp_down_msec; +}; + + +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);

[RFC,v2,1/9] leds: add TI LMU backlight driver

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