[PATCH 1/3] power: pmic: Add driver for ST-Ericsson AB8500 via PRCMU

Stephan Gerhold stephan at gerhold.net
Tue Jul 6 10:52:07 CEST 2021


On Tue, Jul 06, 2021 at 10:08:03AM +0900, Jaehoon Chung wrote:
> On 7/6/21 1:28 AM, Stephan Gerhold wrote:
> > All devices based on ST-Ericsson Ux500 use a PMIC similar to AB8500
> > (Analog Baseband). There is AB8500, AB8505, AB9540 and AB8540
> > although in practice only AB8500 and AB8505 are relevant since the
> > platforms with AB9540 and AB8540 were cancelled and never used in
> > production.
> > 
> > In general, the AB8500 PMIC uses I2C as control interface, where the
> > different register banks are represented as separate I2C devices.
> > However, in practice AB8500 is always connected to a special I2C bus
> > on the DB8500 SoC that is controlled by the power/reset/clock
> > management unit (PRCMU) firmware.
> > 
> > Add a simple driver that allows reading/writing registers of the
> > AB8500 PMIC. The driver directly accesses registers from the PRCMU
> > parent device (represented by syscon in U-Boot). Abstracting it
> > further (e.g. with the i2c uclass) would not provide any advantage
> > because the PRCMU I2C bus is always just connected to AB8500 and
> > vice-versa.
> > 
> > The ab8500.h header is mostly taken as-is from Linux (with some
> > minor adjustments) to allow using similar code in both Linux and
> > U-Boot.
> > 
> > Cc: Linus Walleij <linus.walleij at linaro.org>
> > Signed-off-by: Stephan Gerhold <stephan at gerhold.net>
> > ---
> > 
> >  drivers/power/pmic/Kconfig  |  10 ++
> >  drivers/power/pmic/Makefile |   1 +
> >  drivers/power/pmic/ab8500.c | 258 ++++++++++++++++++++++++++++++++++++
> >  include/power/ab8500.h      | 125 +++++++++++++++++
> >  4 files changed, 394 insertions(+)
> >  create mode 100644 drivers/power/pmic/ab8500.c
> >  create mode 100644 include/power/ab8500.h
> > 
> > diff --git a/drivers/power/pmic/Kconfig b/drivers/power/pmic/Kconfig
> > index 583fd3ddcd..fd6648b313 100644
> > --- a/drivers/power/pmic/Kconfig
> > +++ b/drivers/power/pmic/Kconfig
> > @@ -31,6 +31,16 @@ config SPL_PMIC_CHILDREN
> >  	to call your regulator code (e.g. see rk8xx.c for direct functions
> >  	for use in SPL).
> >  
> > +config PMIC_AB8500
> > +	bool "Enable driver for ST-Ericsson AB8500 PMIC via PRCMU"
> > +	depends on DM_PMIC
> > +	select REGMAP
> > +	select SYSCON
> > +	help
> > +	  Enable support for the ST-Ericsson AB8500 (Analog Baseband) PMIC.
> > +	  It connects with the ST-Ericsson DB8500 SoC via an I2C bus managed by
> > +	  the power/reset/clock management unit (PRCMU) firmware.
> > +
> >  config PMIC_ACT8846
> >  	bool "Enable support for the active-semi 8846 PMIC"
> >  	depends on DM_PMIC && DM_I2C
> > diff --git a/drivers/power/pmic/Makefile b/drivers/power/pmic/Makefile
> > index 89099fde57..5d1a97e5f6 100644
> > --- a/drivers/power/pmic/Makefile
> > +++ b/drivers/power/pmic/Makefile
> > @@ -15,6 +15,7 @@ obj-$(CONFIG_$(SPL_)DM_PMIC_PFUZE100) += pfuze100.o
> >  obj-$(CONFIG_$(SPL_)DM_PMIC_PCA9450) += pca9450.o
> >  obj-$(CONFIG_PMIC_S2MPS11) += s2mps11.o
> >  obj-$(CONFIG_DM_PMIC_SANDBOX) += sandbox.o i2c_pmic_emul.o
> > +obj-$(CONFIG_PMIC_AB8500) += ab8500.o
> >  obj-$(CONFIG_PMIC_ACT8846) += act8846.o
> >  obj-$(CONFIG_PMIC_AS3722) += as3722.o as3722_gpio.o
> >  obj-$(CONFIG_PMIC_MAX8997) += max8997.o
> > diff --git a/drivers/power/pmic/ab8500.c b/drivers/power/pmic/ab8500.c
> > new file mode 100644
> > index 0000000000..a87a3b497c
> > --- /dev/null
> > +++ b/drivers/power/pmic/ab8500.c
> > @@ -0,0 +1,258 @@
> > +// SPDX-License-Identifier: GPL-2.0+
> > +/*
> > + * Copyright (C) 2019 Stephan Gerhold
> > + *
> > + * Adapted from old U-Boot and Linux kernel implementation:
> > + * Copyright (C) STMicroelectronics 2009
> > + * Copyright (C) ST-Ericsson SA 2010
> > + */
> > +
> > +#include <common.h>
> > +#include <dm.h>
> > +#include <regmap.h>
> > +#include <syscon.h>
> > +#include <linux/bitops.h>
> > +#include <linux/err.h>
> > +#include <power/ab8500.h>
> > +#include <power/pmic.h>
> > +
> > +/* CPU mailbox registers */
> > +#define PRCM_MBOX_CPU_VAL		0x0fc
> > +#define PRCM_MBOX_CPU_SET		0x100
> > +#define PRCM_MBOX_CPU_CLR		0x104
> > +
> > +#define PRCM_ARM_IT1_CLR		0x48C
> > +#define PRCM_ARM_IT1_VAL		0x494
> > +
> > +#define PRCM_TCDM_RANGE			2
> > +#define PRCM_REQ_MB5			0xE44
> > +#define PRCM_ACK_MB5			0xDF4
> > +#define _PRCM_MBOX_HEADER		0xFE8
> > +#define PRCM_MBOX_HEADER_REQ_MB5	(_PRCM_MBOX_HEADER + 0x5)
> > +#define PRCMU_I2C_MBOX_BIT		BIT(5)
> > +
> > +/* Mailbox 5 Requests */
> > +#define PRCM_REQ_MB5_I2C_SLAVE_OP	(PRCM_REQ_MB5 + 0x0)
> > +#define PRCM_REQ_MB5_I2C_HW_BITS	(PRCM_REQ_MB5 + 0x1)
> > +#define PRCM_REQ_MB5_I2C_REG		(PRCM_REQ_MB5 + 0x2)
> > +#define PRCM_REQ_MB5_I2C_VAL		(PRCM_REQ_MB5 + 0x3)
> > +#define PRCMU_I2C(bank)			(((bank) << 1) | BIT(6))
> > +#define PRCMU_I2C_WRITE			0
> > +#define PRCMU_I2C_READ			1
> > +#define PRCMU_I2C_STOP_EN		BIT(3)
> > +
> > +/* Mailbox 5 ACKs */
> > +#define PRCM_ACK_MB5_I2C_STATUS		(PRCM_ACK_MB5 + 0x1)
> > +#define PRCM_ACK_MB5_I2C_VAL		(PRCM_ACK_MB5 + 0x3)
> > +#define PRCMU_I2C_WR_OK			0x1
> > +#define PRCMU_I2C_RD_OK			0x2
> > +
> > +/* AB8500 version registers */
> > +#define AB8500_MISC_REV_REG		AB8500_MISC(0x80)
> > +#define AB8500_MISC_IC_NAME_REG		AB8500_MISC(0x82)
> > +
> > +struct ab8500_priv {
> > +	struct ab8500 ab8500;
> > +	struct regmap *regmap;
> > +};
> > +
> > +static inline int prcmu_tcdm_readb(struct regmap *map, uint offset, u8 *valp)
> > +{
> > +	return regmap_raw_read_range(map, PRCM_TCDM_RANGE, offset,
> > +				     valp, sizeof(*valp));
> > +}
> > +
> > +static inline int prcmu_tcdm_writeb(struct regmap *map, uint offset, u8 val)
> > +{
> > +	return regmap_raw_write_range(map, PRCM_TCDM_RANGE, offset,
> > +				      &val, sizeof(val));
> > +}
> > +
> > +static int prcmu_wait_i2c_mbx_ready(struct ab8500_priv *priv)
> > +{
> > +	uint val;
> > +	int ret;
> > +
> > +	ret = regmap_read(priv->regmap, PRCM_ARM_IT1_VAL, &val);
> 
> Doesn't need to check about returned to error?
> 
> > +	if (ret == 0 && val & PRCMU_I2C_MBOX_BIT) {
> > +		printf("ab8500: warning: PRCMU i2c mailbox was not acked\n");
> > +		/* clear mailbox 5 ack irq */
> > +		regmap_write(priv->regmap, PRCM_ARM_IT1_CLR, PRCMU_I2C_MBOX_BIT);
> 
> Not need to check the return value about regmap_write()?
> 

Good point, it's probably better to return in case of errors here.

> > [...]
> > +
> > +	/* clear mailbox 5 ack irq */
> > +	regmap_write(priv->regmap, PRCM_ARM_IT1_CLR, PRCMU_I2C_MBOX_BIT);
> 
> Ditto.
> 

But here it doesn't really make sense: The read/write is already done.
Even if we don't manage to clear the IRQ the read/write will still have
succeeded. I will add a comment to clarify this.

> > +
> > +	if (status != expected_status) {
> > +		/*
> > +		 * AB8500 does not have the AB8500_MISC_IC_NAME_REG register,
> > +		 * but we need to try reading it to detect AB8505.
> > +		 * In case of an error, assume that we have AB8500.
> > +		 */
> > +		if (op == PRCMU_I2C_READ && bank_reg == AB8500_MISC_IC_NAME_REG) {
> > +			*val = AB8500_VERSION_AB8500;
> > +			return 0;
> > +		}
> > +
> > +		printf("%s: return status %d\n", __func__, status);
> > +		return -EIO;
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +static int ab8500_reg_count(struct udevice *dev)
> > +{
> > +	return AB8500_NUM_REGISTERS;
> > +}
> > +
> > +static int ab8500_read(struct udevice *dev, uint reg, uint8_t *buf, int len)
> > +{
> > +	int ret;
> > +
> > +	if (len != 1)
> > +		return -EINVAL;
> > +
> > +	*buf = 0;
> > +	ret = ab8500_transfer(dev, reg, buf, PRCMU_I2C_READ, PRCMU_I2C_RD_OK);
> > +	if (ret) {
> > +		printf("%s failed: %d\n", __func__, ret);
> > +		return ret;
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +static int ab8500_write(struct udevice *dev, uint reg, const uint8_t *buf, int len)
> > +{
> > +	int ret;
> > +	u8 val;
> > +
> > +	if (len != 1)
> > +		return -EINVAL;
> > +
> > +	val = *buf;
> > +	ret = ab8500_transfer(dev, reg, &val, PRCMU_I2C_WRITE, PRCMU_I2C_WR_OK);
> > +	if (ret) {
> > +		printf("%s failed: %d\n", __func__, ret);
> > +		return ret;
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +static struct dm_pmic_ops ab8500_ops = {
> > +	.reg_count = ab8500_reg_count,
> > +	.read = ab8500_read,
> > +	.write = ab8500_write,
> > +};
> > +
> > +static int ab8500_probe(struct udevice *dev)
> > +{
> > +	struct ab8500_priv *priv = dev_get_priv(dev);
> > +	int ret;
> > +
> > +	/* get regmap from the PRCMU parent device (syscon in U-Boot) */
> > +	priv->regmap = syscon_get_regmap(dev->parent);
> > +	if (IS_ERR(priv->regmap))
> > +		return PTR_ERR(priv->regmap);
> > +
> > +	ret = pmic_reg_read(dev, AB8500_MISC_IC_NAME_REG);
> > +	if (ret < 0) {
> > +		printf("ab8500: failed to read chip version: %d\n", ret);
> > +		return ret;
> > +	}
> > +	priv->ab8500.version = ret;
> > +
> > +	ret = pmic_reg_read(dev, AB8500_MISC_REV_REG);
> > +	if (ret < 0) {
> > +		printf("ab8500: failed to read chip id: %d\n", ret);
> > +		return ret;
> > +	}
> > +	priv->ab8500.chip_id = ret;
> > +
> > +	debug("ab8500: version: %#x, chip id: %#x\n",
> > +	      priv->ab8500.version, priv->ab8500.chip_id);
> > +
> > +	return 0;
> > +}
> > +
> > +static const struct udevice_id ab8500_ids[] = {
> > +	{ .compatible = "stericsson,ab8500" },
> > +	{ }
> > +};
> > +
> > +U_BOOT_DRIVER(pmic_ab8500) = {
> > +	.name		= "pmic_ab8500",
> > +	.id		= UCLASS_PMIC,
> > +	.of_match	= ab8500_ids,
> > +	.bind		= dm_scan_fdt_dev,
> > +	.probe		= ab8500_probe,
> > +	.ops		= &ab8500_ops,
> > +	.priv_auto	= sizeof(struct ab8500_priv),
> > +};
> > diff --git a/include/power/ab8500.h b/include/power/ab8500.h
> > new file mode 100644
> > index 0000000000..157eb4a5b1
> > --- /dev/null
> > +++ b/include/power/ab8500.h
> > @@ -0,0 +1,125 @@
> > +/* SPDX-License-Identifier: GPL-2.0-only */
> > +/*
> > + * Based on include/linux/mfd/abx500/ab8500.h from Linux
> > + * Copyright (C) ST-Ericsson SA 2010
> > + * Author: Srinidhi Kasagar <srinidhi.kasagar at stericsson.com>
> > + */
> > +
> > +#ifndef _PMIC_AB8500_H_
> > +#define _PMIC_AB8500_H_
> > +
> > +/*
> > + * AB IC versions
> > + *
> > + * AB8500_VERSION_AB8500 should be 0xFF but will never be read as need a
> > + * non-supported multi-byte I2C access via PRCMU. Set to 0x00 to ease the
> > + * print of version string.
> > + */
> > +enum ab8500_version {
> > +	AB8500_VERSION_AB8500 = 0x0,
> > +	AB8500_VERSION_AB8505 = 0x1,
> > +	AB8500_VERSION_AB9540 = 0x2,
> > +	AB8500_VERSION_AB8540 = 0x4,
> > +	AB8500_VERSION_UNDEFINED,
> > +};
> > +
> > +/* AB8500 CIDs*/
> > +#define AB8500_CUTEARLY	0x00
> > +#define AB8500_CUT1P0	0x10
> > +#define AB8500_CUT1P1	0x11
> > +#define AB8500_CUT1P2	0x12 /* Only valid for AB8540 */
> > +#define AB8500_CUT2P0	0x20
> > +#define AB8500_CUT3P0	0x30
> > +#define AB8500_CUT3P3	0x33
> > +
> > +/*
> > + * AB8500 bank addresses
> > + */
> > +#define AB8500_BANK(bank, reg)		(((bank) << 8) | (reg))
> > +#define AB8500_M_FSM_RANK(reg)		AB8500_BANK(0x0, reg)
> > +#define AB8500_SYS_CTRL1_BLOCK(reg)	AB8500_BANK(0x1, reg)
> > +#define AB8500_SYS_CTRL2_BLOCK(reg)	AB8500_BANK(0x2, reg)
> > +#define AB8500_REGU_CTRL1(reg)		AB8500_BANK(0x3, reg)
> > +#define AB8500_REGU_CTRL2(reg)		AB8500_BANK(0x4, reg)
> > +#define AB8500_USB(reg)			AB8500_BANK(0x5, reg)
> > +#define AB8500_TVOUT(reg)		AB8500_BANK(0x6, reg)
> > +#define AB8500_DBI(reg)			AB8500_BANK(0x7, reg)
> > +#define AB8500_ECI_AV_ACC(reg)		AB8500_BANK(0x8, reg)
> > +#define AB8500_RESERVED(reg)		AB8500_BANK(0x9, reg)
> > +#define AB8500_GPADC(reg)		AB8500_BANK(0xA, reg)
> > +#define AB8500_CHARGER(reg)		AB8500_BANK(0xB, reg)
> > +#define AB8500_GAS_GAUGE(reg)		AB8500_BANK(0xC, reg)
> > +#define AB8500_AUDIO(reg)		AB8500_BANK(0xD, reg)
> > +#define AB8500_INTERRUPT(reg)		AB8500_BANK(0xE, reg)
> > +#define AB8500_RTC(reg)			AB8500_BANK(0xF, reg)
> > +#define AB8500_GPIO(reg)		AB8500_BANK(0x10, reg)
> > +#define AB8500_MISC(reg)		AB8500_BANK(0x10, reg)
> > +#define AB8500_DEVELOPMENT(reg)		AB8500_BANK(0x11, reg)
> > +#define AB8500_DEBUG(reg)		AB8500_BANK(0x12, reg)
> > +#define AB8500_PROD_TEST(reg)		AB8500_BANK(0x13, reg)
> > +#define AB8500_STE_TEST(reg)		AB8500_BANK(0x14, reg)
> > +#define AB8500_OTP_EMUL(reg)		AB8500_BANK(0x15, reg)
> > +
> > +#define AB8500_NUM_BANKS		0x16
> > +#define AB8500_NUM_REGISTERS		AB8500_BANK(AB8500_NUM_BANKS, 0)
> > +
> > +struct ab8500 {
> > +	enum ab8500_version version;
> > +	u8 chip_id;
> > +};> +
> 
> I have checked that below codes are existed in linux kernel. 
> But I didn't find where the below codes is used in U-boot.
> Will it be used in future? 
> 

At the moment I don't have any drivers myself that make use of this.
However, it would certainly be needed if more advanced drivers for
AB8500 are written. I don't know if this will happen anytime soon.

I can remove these if you would prefer to have them added once they are
actually needed. What do you think?

Thanks!
Stephan

> > +static inline int is_ab8500(struct ab8500 *ab)
> > +{
> > +	return ab->version == AB8500_VERSION_AB8500;
> > +}
> > +
> > +static inline int is_ab8505(struct ab8500 *ab)
> > +{
> > +	return ab->version == AB8500_VERSION_AB8505;
> > +}
> > +
> > +/* exclude also ab8505, ab9540... */
> > +static inline int is_ab8500_1p0_or_earlier(struct ab8500 *ab)
> > +{
> > +	return (is_ab8500(ab) && (ab->chip_id <= AB8500_CUT1P0));
> > +}
> > +
> > +/* exclude also ab8505, ab9540... */
> > +static inline int is_ab8500_1p1_or_earlier(struct ab8500 *ab)
> > +{
> > +	return (is_ab8500(ab) && (ab->chip_id <= AB8500_CUT1P1));
> > +}
> > +
> > +/* exclude also ab8505, ab9540... */
> > +static inline int is_ab8500_2p0_or_earlier(struct ab8500 *ab)
> > +{
> > +	return (is_ab8500(ab) && (ab->chip_id <= AB8500_CUT2P0));
> > +}
> > +
> > +static inline int is_ab8500_3p3_or_earlier(struct ab8500 *ab)
> > +{
> > +	return (is_ab8500(ab) && (ab->chip_id <= AB8500_CUT3P3));
> > +}
> > +
> > +/* exclude also ab8505, ab9540... */
> > +static inline int is_ab8500_2p0(struct ab8500 *ab)
> > +{
> > +	return (is_ab8500(ab) && (ab->chip_id == AB8500_CUT2P0));
> > +}
> > +
> > +static inline int is_ab8505_1p0_or_earlier(struct ab8500 *ab)
> > +{
> > +	return (is_ab8505(ab) && (ab->chip_id <= AB8500_CUT1P0));
> > +}
> > +
> > +static inline int is_ab8505_2p0(struct ab8500 *ab)
> > +{
> > +	return (is_ab8505(ab) && (ab->chip_id == AB8500_CUT2P0));
> > +}
> > +
> > +static inline int is_ab8505_2p0_earlier(struct ab8500 *ab)
> > +{
> > +	return (is_ab8505(ab) && (ab->chip_id < AB8500_CUT2P0));
> > +}
> > +
> > +#endif
> > 
> 


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