[U-Boot] [PATCH] power: LP8720 regulator support

[Paul Kocialkowski <contact@paulk.fr>]

Le mardi 28 octobre 2014 ? 18:32 +0100, Paul Kocialkowski a ?crit :
> This adds support for the LP8720 i2c regulator, as found in e.g. the LG
> Optimus Black (P970), codename sniper. This code supports setting up and
> enabling one of the 5 LDOs that the IC provides.
> Other more advanced features are unsupported.
> 
> Signed-off-by: Paul Kocialkowski <contact@paulk.fr>
> ---
>  drivers/power/Makefile |    1 +
>  drivers/power/lp8720.c |  107 ++++++++++++++++++++++++++++++++++++++++++++++++
>  include/lp8720.h       |   93 +++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 201 insertions(+)
>  create mode 100644 drivers/power/lp8720.c
>  create mode 100644 include/lp8720.h
> 
> diff --git a/drivers/power/Makefile b/drivers/power/Makefile
> index dc64e4d..65be5a0 100644
> --- a/drivers/power/Makefile
> +++ b/drivers/power/Makefile
> @@ -9,6 +9,7 @@ obj-$(CONFIG_AXP152_POWER)	+= axp152.o
>  obj-$(CONFIG_AXP209_POWER)	+= axp209.o
>  obj-$(CONFIG_EXYNOS_TMU)	+= exynos-tmu.o
>  obj-$(CONFIG_FTPMU010_POWER)	+= ftpmu010.o
> +obj-$(CONFIG_LP8720_POWER)	+= lp8720.o
>  obj-$(CONFIG_TPS6586X_POWER)	+= tps6586x.o
>  obj-$(CONFIG_TWL4030_POWER)	+= twl4030.o
>  obj-$(CONFIG_TWL6030_POWER)	+= twl6030.o
> diff --git a/drivers/power/lp8720.c b/drivers/power/lp8720.c
> new file mode 100644
> index 0000000..ac7fc11
> --- /dev/null
> +++ b/drivers/power/lp8720.c
> @@ -0,0 +1,107 @@
> +/*
> + * Copyright (C) 2014 Paul Kocialkowski <contact@paulk.fr>
> + *
> + * SPDX-License-Identifier:	GPL-2.0+
> + */
> +
> +#include <common.h>
> +#include <i2c.h>
> +#include <asm/gpio.h>
> +#include <lp8720.h>
> +
> +static struct lp8720_info lp8720_info;
> +
> +static int lp8720_write(u8 reg, u8 val)
> +{
> +	return i2c_write(lp8720_info.chip_idsel, reg, 1, &val, 1);
> +}
> +
> +static int lp8720_read(u8 reg, u8 *val)
> +{
> +	return i2c_read(lp8720_info.chip_idsel, reg, 1, val, 1);
> +}

Should I ifdef for I2C and GPIO support? It seems that GPIO support only
has board-sepcific config options, so this may be hard. There is
CONFIG_DM_GPIO for driver model, but it is apparently not always used,
especially not on SPL.

> +int lp8720_init(int enable_gpio, int chip_idsel)
> +{
> +	int ret;
> +
> +	if (enable_gpio) {

I'm guessing that in the case of a provided negative GPIO, this will
return -1, which is not appropriate behavior (the regulator can still be
used without an enable GPIO). I should probbaly directly go with
gpio_is_valid.

> +		if (!gpio_is_valid(enable_gpio))
> +			return -1;
> +
> +		ret = gpio_request(enable_gpio, "lp8720_en");
> +		if (ret)
> +			return ret;
> +
> +		ret = gpio_direction_output(enable_gpio, 0);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	lp8720_info.enable_gpio = enable_gpio;
> +	lp8720_info.chip_idsel = chip_idsel;
> +
> +	return 0;
> +}
> +
> +int lp8720_enable(void)
> +{
> +	int ret;
> +
> +	if (lp8720_info.enable_gpio) {
> +		ret = gpio_set_value(lp8720_info.enable_gpio, 1);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +int lp8720_is_enabled(void)
> +{
> +	if (lp8720_info.enable_gpio)
> +		return gpio_get_value(lp8720_info.enable_gpio);
> +
> +	/* Assume LP8720 enabled when there is no enable GPIO */
> +	return 1;
> +}
> +
> +int lp8720_ldo_enable(u8 ldo_enable)
> +{
> +	u8 val;
> +	int ret;
> +
> +	ret = lp8720_read(LP8720_ENABLE_BITS, &val);
> +	if (ret)
> +		return ret;
> +
> +	val |= ldo_enable;
> +
> +	ret = lp8720_write(LP8720_ENABLE_BITS, val);
> +	if (ret)
> +		return ret;
> +
> +	/* Enable the IC */
> +	if (!lp8720_is_enabled())
> +		lp8720_enable();
> +
> +	return 0;
> +}
> +
> +int lp8720_ldo_voltage(u8 ldo_reg, u8 voltage, u8 delay)
> +{
> +	u8 val;
> +	int ret;
> +
> +	/* Register V field */
> +	val = voltage & 0x1F;
> +
> +	/* Register T field */
> +	val |= (delay & 0x07) << 5;
> +
> +	ret = lp8720_write(ldo_reg, val);
> +	if (ret)
> +		return ret;
> +
> +	return 0;
> +}
> diff --git a/include/lp8720.h b/include/lp8720.h
> new file mode 100644
> index 0000000..033f2c4
> --- /dev/null
> +++ b/include/lp8720.h
> @@ -0,0 +1,93 @@
> +/*
> + * Copyright (C) 2014 Paul Kocialkowski <contact@paulk.fr>
> + *
> + * SPDX-License-Identifier:	GPL-2.0+
> + */
> +
> +#ifndef LP8720_H
> +#define LP8720_H
> +
> +#include <common.h>
> +
> +/*
> + * Chip ID selection
> + */
> +
> +#define LP8720_CHIP_IDSEL_VBATT		0x7F
> +#define LP8720_CHIP_IDSEL_HI_Z		0x7C
> +#define LP8720_CHIP_IDSEL_GND		0x7D
> +
> +/*
> + * Registers
> + */
> +
> +#define LP8720_GENERAL_SETTINGS		0x00
> +#define LP8720_LDO1_SETTINGS		0x01
> +#define LP8720_LDO2_SETTINGS		0x02
> +#define LP8720_LDO3_SETTINGS		0x03
> +#define LP8720_LDO4_SETTINGS		0x04
> +#define LP8720_LDO5_SETTINGS		0x05
> +#define LP8720_BUCK_SETTINGS1		0x06
> +#define LP8720_BUCK_SETTINGS2		0x07
> +#define LP8720_ENABLE_BITS		0x08
> +#define LP8720_PULLDOWN_BITS		0x09
> +#define LP8720_STATUS_BITS		0x0A
> +#define LP8720_INTERRUPT_BITS		0x0B
> +#define LP8720_INTERRUPT_MASK		0x0C
> +
> +/*
> + * Values
> + */
> +
> +/* LP8720_GENERAL_SETTINGS */
> +#define LP8720_25_US_TIME_STEP		(1 << 0)
> +#define LP8720_50_US_TIME_STEP		(0 << 0)
> +
> +/* LP8720_LDO*_SETTINGS */
> +#define LP8720_LDO1235_V_12		0x00
> +#define LP8720_LDO1235_V_18		0x0C
> +#define LP8720_LDO1235_V_30		0x1D
> +#define LP8720_LDO1235_V_33		0x1F
> +
> +#define LP8720_LDO4_V_12		0x00
> +#define LP8720_LDO4_V_14		0x09
> +#define LP8720_LDO4_V_18		0x11
> +#define LP8720_LDO4_V_28		0x1E
> +
> +#define LP8720_DELAY_0			0
> +#define LP8720_DELAY_1_TS		1
> +#define LP8720_DELAY_2_TS		2
> +#define LP8720_DELAY_3_TS		3
> +#define LP8720_DELAY_4_TS		4
> +#define LP8720_DELAY_5_TS		5
> +#define LP8720_DELAY_6_TS		6
> +#define LP8720_DELAY_NO_START		7
> +
> +/* LP8720_ENABLE_BITS */
> +#define LP8720_LDO1_EN			(1 << 0)
> +#define LP8720_LDO2_EN			(1 << 1)
> +#define LP8720_LDO3_EN			(1 << 2)
> +#define LP8720_LDO4_EN			(1 << 3)
> +#define LP8720_LDO5_EN			(1 << 4)
> +#define LP8720_BUCK_EN			(1 << 5)
> +
> +/*
> + * Driver info
> + */
> +
> +struct lp8720_info {
> +	int enable_gpio;
> +	int chip_idsel;
> +};
> +
> +/*
> + * Declarations
> + */
> +
> +int lp8720_init(int enable_gpio, int chip_idsel);
> +int lp8720_enable(void);
> +int lp8720_is_enabled(void);
> +int lp8720_ldo_enable(u8 ldo_enable);
> +int lp8720_ldo_voltage(u8 ldo_reg, u8 voltage, u8 delay);
> +
> +#endif

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