[PATCH v2 08/12] i2c: Add a DM_I2C driver for the sun8i RSB controller

Andre Przywara andre.przywara at arm.com
Tue Oct 12 12:49:24 CEST 2021


On Fri,  8 Oct 2021 00:17:21 -0500
Samuel Holland <samuel at sholland.org> wrote:

> This bus controller is used to communicate with an X-Powers AXP PMIC.
> Currently, various drivers access PMIC registers through a platform-
> specific non-DM "pmic_bus" interface, which depends on the legacy I2C
> framework. In order to convert those drivers to use DM_PMIC, this bus
> needs a DM_I2C driver.
> 
> Refactor the rsb functions to take the base address as a parameter,
> and implement both the existing interface (which is still needed in
> SPL) and the DM_I2C interface on top of them.

I diff'ed the (slightly tweaked) old version and the new file, and can
indeed confirm that it's a conversion that preserves the actual
functionality. The new DM wrappers look good as well.

> The register for switching between I2C/P2WI/RSB mode is the same across
> all PMIC variants, so move that to the common header.
> 
> There are only a couple of pairs of hardware/runtime addresses used
> across all PMIC variants. So far the code expected only the "primary"
> pair, but some PMICs like the AXP305 and AXP805 use the secondary pair,
> so add support for that to the DM driver as well.
> 
> Signed-off-by: Samuel Holland <samuel at sholland.org>

Reviewed-by: Andre Przywara <andre.przywara at arm.com>

Cheers,
Andre

> ---
> 
> Changes in v2:
> - Renamed Kconfig symbol to SYS_I2C_SUN8I_RSB
> - Moved entire RSB driver source to drivers/i2c
> 
>  arch/arm/mach-sunxi/Kconfig    |  20 +--
>  arch/arm/mach-sunxi/Makefile   |   1 -
>  arch/arm/mach-sunxi/pmic_bus.c |  11 +-
>  arch/arm/mach-sunxi/rsb.c      | 175 --------------------
>  drivers/i2c/Kconfig            |   8 +
>  drivers/i2c/Makefile           |   1 +
>  drivers/i2c/sun8i_rsb.c        | 281 +++++++++++++++++++++++++++++++++
>  include/axp_pmic.h             |   6 +
>  8 files changed, 308 insertions(+), 195 deletions(-)
>  delete mode 100644 arch/arm/mach-sunxi/rsb.c
>  create mode 100644 drivers/i2c/sun8i_rsb.c
> 
> diff --git a/arch/arm/mach-sunxi/Kconfig b/arch/arm/mach-sunxi/Kconfig
> index ae3b7974f09..df160c9a775 100644
> --- a/arch/arm/mach-sunxi/Kconfig
> +++ b/arch/arm/mach-sunxi/Kconfig
> @@ -100,14 +100,6 @@ config AXP_PMIC_BUS
>  	  Select this PMIC bus access helpers for Sunxi platform PRCM or other
>  	  AXP family PMIC devices.
>  
> -config SUN8I_RSB
> -	bool "Allwinner sunXi Reduced Serial Bus Driver"
> -	help
> -	  Say y here to enable support for Allwinner's Reduced Serial Bus
> -	  (RSB) support. This controller is responsible for communicating
> -	  with various RSB based devices, such as AXP223, AXP8XX PMICs,
> -	  and AC100/AC200 ICs.
> -
>  config SUNXI_SRAM_ADDRESS
>  	hex
>  	default 0x10000 if MACH_SUN9I || MACH_SUN50I || MACH_SUN50I_H5
> @@ -250,9 +242,10 @@ config MACH_SUN8I_A23
>  	select ARCH_SUPPORT_PSCI
>  	select DRAM_SUN8I_A23
>  	select PHY_SUN4I_USB
> -	select SUN8I_RSB
> +	select SPL_I2C
>  	select SUNXI_GEN_SUN6I
>  	select SUPPORT_SPL
> +	select SYS_I2C_SUN8I_RSB
>  	select ARMV7_BOOT_SEC_DEFAULT if OLD_SUNXI_KERNEL_COMPAT
>  	imply CONS_INDEX_5 if !DM_SERIAL
>  
> @@ -264,9 +257,10 @@ config MACH_SUN8I_A33
>  	select ARCH_SUPPORT_PSCI
>  	select DRAM_SUN8I_A33
>  	select PHY_SUN4I_USB
> -	select SUN8I_RSB
> +	select SPL_I2C
>  	select SUNXI_GEN_SUN6I
>  	select SUPPORT_SPL
> +	select SYS_I2C_SUN8I_RSB
>  	select ARMV7_BOOT_SEC_DEFAULT if OLD_SUNXI_KERNEL_COMPAT
>  	imply CONS_INDEX_5 if !DM_SERIAL
>  
> @@ -275,11 +269,12 @@ config MACH_SUN8I_A83T
>  	select CPU_V7A
>  	select DRAM_SUN8I_A83T
>  	select PHY_SUN4I_USB
> -	select SUN8I_RSB
> +	select SPL_I2C
>  	select SUNXI_GEN_SUN6I
>  	select MMC_SUNXI_HAS_NEW_MODE
>  	select MMC_SUNXI_HAS_MODE_SWITCH
>  	select SUPPORT_SPL
> +	select SYS_I2C_SUN8I_RSB
>  
>  config MACH_SUN8I_H3
>  	bool "sun8i (Allwinner H3)"
> @@ -320,10 +315,11 @@ config MACH_SUN9I
>  	bool "sun9i (Allwinner A80)"
>  	select CPU_V7A
>  	select DRAM_SUN9I
> +	select SPL_I2C
>  	select SUN6I_PRCM
>  	select SUNXI_GEN_SUN6I
> -	select SUN8I_RSB
>  	select SUPPORT_SPL
> +	select SYS_I2C_SUN8I_RSB
>  
>  config MACH_SUN50I
>  	bool "sun50i (Allwinner A64)"
> diff --git a/arch/arm/mach-sunxi/Makefile b/arch/arm/mach-sunxi/Makefile
> index c9312bb3934..5d3fd70f749 100644
> --- a/arch/arm/mach-sunxi/Makefile
> +++ b/arch/arm/mach-sunxi/Makefile
> @@ -13,7 +13,6 @@ obj-y	+= dram_helpers.o
>  obj-y	+= pinmux.o
>  obj-$(CONFIG_SUN6I_PRCM)	+= prcm.o
>  obj-$(CONFIG_AXP_PMIC_BUS)	+= pmic_bus.o
> -obj-$(CONFIG_SUN8I_RSB)		+= rsb.o
>  obj-$(CONFIG_MACH_SUN4I)	+= clock_sun4i.o
>  obj-$(CONFIG_MACH_SUN5I)	+= clock_sun4i.o
>  obj-$(CONFIG_MACH_SUN6I)	+= clock_sun6i.o
> diff --git a/arch/arm/mach-sunxi/pmic_bus.c b/arch/arm/mach-sunxi/pmic_bus.c
> index 673a05fdd16..827797249ea 100644
> --- a/arch/arm/mach-sunxi/pmic_bus.c
> +++ b/arch/arm/mach-sunxi/pmic_bus.c
> @@ -23,10 +23,6 @@
>  
>  #define AXP221_CHIP_ADDR		0x68
>  
> -/* AXP818 device and runtime addresses are same as AXP223 */
> -#define AXP223_DEVICE_ADDR		0x3a3
> -#define AXP223_RUNTIME_ADDR		0x2d
> -
>  int pmic_bus_init(void)
>  {
>  	/* This cannot be 0 because it is used in SPL before BSS is ready */
> @@ -49,7 +45,8 @@ int pmic_bus_init(void)
>  	if (ret)
>  		return ret;
>  
> -	ret = rsb_set_device_address(AXP223_DEVICE_ADDR, AXP223_RUNTIME_ADDR);
> +	ret = rsb_set_device_address(AXP_PMIC_PRI_DEVICE_ADDR,
> +				     AXP_PMIC_PRI_RUNTIME_ADDR);
>  # endif
>  	if (ret)
>  		return ret;
> @@ -73,7 +70,7 @@ int pmic_bus_read(u8 reg, u8 *data)
>  # elif defined CONFIG_MACH_SUN8I_R40
>  	return i2c_read(AXP209_I2C_ADDR, reg, 1, data, 1);
>  # else
> -	return rsb_read(AXP223_RUNTIME_ADDR, reg, data);
> +	return rsb_read(AXP_PMIC_PRI_RUNTIME_ADDR, reg, data);
>  # endif
>  #endif
>  }
> @@ -92,7 +89,7 @@ int pmic_bus_write(u8 reg, u8 data)
>  # elif defined CONFIG_MACH_SUN8I_R40
>  	return i2c_write(AXP209_I2C_ADDR, reg, 1, &data, 1);
>  # else
> -	return rsb_write(AXP223_RUNTIME_ADDR, reg, data);
> +	return rsb_write(AXP_PMIC_PRI_RUNTIME_ADDR, reg, data);
>  # endif
>  #endif
>  }
> diff --git a/arch/arm/mach-sunxi/rsb.c b/arch/arm/mach-sunxi/rsb.c
> deleted file mode 100644
> index 01bb09b7478..00000000000
> --- a/arch/arm/mach-sunxi/rsb.c
> +++ /dev/null
> @@ -1,175 +0,0 @@
> -// SPDX-License-Identifier: GPL-2.0+
> -/*
> - * (C) Copyright 2014 Hans de Goede <hdegoede at redhat.com>
> - *
> - * Based on allwinner u-boot sources rsb code which is:
> - * (C) Copyright 2007-2013
> - * Allwinner Technology Co., Ltd. <www.allwinnertech.com>
> - * lixiang <lixiang at allwinnertech.com>
> - */
> -
> -#include <common.h>
> -#include <errno.h>
> -#include <time.h>
> -#include <asm/arch/cpu.h>
> -#include <asm/arch/gpio.h>
> -#include <asm/arch/prcm.h>
> -#include <asm/arch/rsb.h>
> -
> -static int rsb_set_device_mode(void);
> -
> -static void rsb_cfg_io(void)
> -{
> -#ifdef CONFIG_MACH_SUN8I
> -	sunxi_gpio_set_cfgpin(SUNXI_GPL(0), SUN8I_GPL_R_RSB);
> -	sunxi_gpio_set_cfgpin(SUNXI_GPL(1), SUN8I_GPL_R_RSB);
> -	sunxi_gpio_set_pull(SUNXI_GPL(0), 1);
> -	sunxi_gpio_set_pull(SUNXI_GPL(1), 1);
> -	sunxi_gpio_set_drv(SUNXI_GPL(0), 2);
> -	sunxi_gpio_set_drv(SUNXI_GPL(1), 2);
> -#elif defined CONFIG_MACH_SUN9I
> -	sunxi_gpio_set_cfgpin(SUNXI_GPN(0), SUN9I_GPN_R_RSB);
> -	sunxi_gpio_set_cfgpin(SUNXI_GPN(1), SUN9I_GPN_R_RSB);
> -	sunxi_gpio_set_pull(SUNXI_GPN(0), 1);
> -	sunxi_gpio_set_pull(SUNXI_GPN(1), 1);
> -	sunxi_gpio_set_drv(SUNXI_GPN(0), 2);
> -	sunxi_gpio_set_drv(SUNXI_GPN(1), 2);
> -#else
> -#error unsupported MACH_SUNXI
> -#endif
> -}
> -
> -static void rsb_set_clk(void)
> -{
> -	struct sunxi_rsb_reg * const rsb =
> -		(struct sunxi_rsb_reg *)SUNXI_RSB_BASE;
> -	u32 div = 0;
> -	u32 cd_odly = 0;
> -
> -	/* Source is Hosc24M, set RSB clk to 3Mhz */
> -	div = 24000000 / 3000000 / 2 - 1;
> -	cd_odly = div >> 1;
> -	if (!cd_odly)
> -		cd_odly = 1;
> -
> -	writel((cd_odly << 8) | div, &rsb->ccr);
> -}
> -
> -int rsb_init(void)
> -{
> -	struct sunxi_rsb_reg * const rsb =
> -		(struct sunxi_rsb_reg *)SUNXI_RSB_BASE;
> -
> -	/* Enable RSB and PIO clk, and de-assert their resets */
> -	prcm_apb0_enable(PRCM_APB0_GATE_PIO | PRCM_APB0_GATE_RSB);
> -
> -	/* Setup external pins */
> -	rsb_cfg_io();
> -
> -	writel(RSB_CTRL_SOFT_RST, &rsb->ctrl);
> -	rsb_set_clk();
> -
> -	return rsb_set_device_mode();
> -}
> -
> -static int rsb_await_trans(void)
> -{
> -	struct sunxi_rsb_reg * const rsb =
> -		(struct sunxi_rsb_reg *)SUNXI_RSB_BASE;
> -	unsigned long tmo = timer_get_us() + 1000000;
> -	u32 stat;
> -	int ret;
> -
> -	while (1) {
> -		stat = readl(&rsb->stat);
> -		if (stat & RSB_STAT_LBSY_INT) {
> -			ret = -EBUSY;
> -			break;
> -		}
> -		if (stat & RSB_STAT_TERR_INT) {
> -			ret = -EIO;
> -			break;
> -		}
> -		if (stat & RSB_STAT_TOVER_INT) {
> -			ret = 0;
> -			break;
> -		}
> -		if (timer_get_us() > tmo) {
> -			ret = -ETIME;
> -			break;
> -		}
> -	}
> -	writel(stat, &rsb->stat); /* Clear status bits */
> -
> -	return ret;
> -}
> -
> -static int rsb_set_device_mode(void)
> -{
> -	struct sunxi_rsb_reg * const rsb =
> -		(struct sunxi_rsb_reg *)SUNXI_RSB_BASE;
> -	unsigned long tmo = timer_get_us() + 1000000;
> -
> -	writel(RSB_DMCR_DEVICE_MODE_START | RSB_DMCR_DEVICE_MODE_DATA,
> -	       &rsb->dmcr);
> -
> -	while (readl(&rsb->dmcr) & RSB_DMCR_DEVICE_MODE_START) {
> -		if (timer_get_us() > tmo)
> -			return -ETIME;
> -	}
> -
> -	return rsb_await_trans();
> -}
> -
> -static int rsb_do_trans(void)
> -{
> -	struct sunxi_rsb_reg * const rsb =
> -		(struct sunxi_rsb_reg *)SUNXI_RSB_BASE;
> -
> -	setbits_le32(&rsb->ctrl, RSB_CTRL_START_TRANS);
> -	return rsb_await_trans();
> -}
> -
> -int rsb_set_device_address(u16 device_addr, u16 runtime_addr)
> -{
> -	struct sunxi_rsb_reg * const rsb =
> -		(struct sunxi_rsb_reg *)SUNXI_RSB_BASE;
> -
> -	writel(RSB_DEVADDR_RUNTIME_ADDR(runtime_addr) |
> -	       RSB_DEVADDR_DEVICE_ADDR(device_addr), &rsb->devaddr);
> -	writel(RSB_CMD_SET_RTSADDR, &rsb->cmd);
> -
> -	return rsb_do_trans();
> -}
> -
> -int rsb_write(const u16 runtime_device_addr, const u8 reg_addr, u8 data)
> -{
> -	struct sunxi_rsb_reg * const rsb =
> -		(struct sunxi_rsb_reg *)SUNXI_RSB_BASE;
> -
> -	writel(RSB_DEVADDR_RUNTIME_ADDR(runtime_device_addr), &rsb->devaddr);
> -	writel(reg_addr, &rsb->addr);
> -	writel(data, &rsb->data);
> -	writel(RSB_CMD_BYTE_WRITE, &rsb->cmd);
> -
> -	return rsb_do_trans();
> -}
> -
> -int rsb_read(const u16 runtime_device_addr, const u8 reg_addr, u8 *data)
> -{
> -	struct sunxi_rsb_reg * const rsb =
> -		(struct sunxi_rsb_reg *)SUNXI_RSB_BASE;
> -	int ret;
> -
> -	writel(RSB_DEVADDR_RUNTIME_ADDR(runtime_device_addr), &rsb->devaddr);
> -	writel(reg_addr, &rsb->addr);
> -	writel(RSB_CMD_BYTE_READ, &rsb->cmd);
> -
> -	ret = rsb_do_trans();
> -	if (ret)
> -		return ret;
> -
> -	*data = readl(&rsb->data) & 0xff;
> -
> -	return 0;
> -}
> diff --git a/drivers/i2c/Kconfig b/drivers/i2c/Kconfig
> index 0adf143abfd..66bd6fe2f34 100644
> --- a/drivers/i2c/Kconfig
> +++ b/drivers/i2c/Kconfig
> @@ -583,6 +583,14 @@ config SYS_I2C_SUN6I_P2WI
>  	  in the Allwinner A31 and A31s SOCs. This interface is used to connect
>  	  to specific devices like the X-Powers AXP221 PMIC.
>  
> +config SYS_I2C_SUN8I_RSB
> +	bool "Allwinner sun8i Reduced Serial Bus controller"
> +	depends on ARCH_SUNXI
> +	help
> +	  Support for Allwinner's Reduced Serial Bus (RSB) controller. This
> +	  controller is responsible for communicating with various RSB based
> +	  devices, such as X-Powers AXPxxx PMICs and AC100/AC200 CODEC ICs.
> +
>  config SYS_I2C_SYNQUACER
>  	bool "Socionext SynQuacer I2C controller"
>  	depends on ARCH_SYNQUACER && DM_I2C
> diff --git a/drivers/i2c/Makefile b/drivers/i2c/Makefile
> index 0a2cc641930..916427452a5 100644
> --- a/drivers/i2c/Makefile
> +++ b/drivers/i2c/Makefile
> @@ -44,6 +44,7 @@ obj-$(CONFIG_SYS_I2C_SH) += sh_i2c.o
>  obj-$(CONFIG_SYS_I2C_SOFT) += soft_i2c.o
>  obj-$(CONFIG_SYS_I2C_STM32F7) += stm32f7_i2c.o
>  obj-$(CONFIG_SYS_I2C_SUN6I_P2WI) += sun6i_p2wi.o
> +obj-$(CONFIG_SYS_I2C_SUN8I_RSB) += sun8i_rsb.o
>  obj-$(CONFIG_SYS_I2C_SYNQUACER) += synquacer_i2c.o
>  obj-$(CONFIG_SYS_I2C_TEGRA) += tegra_i2c.o
>  obj-$(CONFIG_SYS_I2C_UNIPHIER) += i2c-uniphier.o
> diff --git a/drivers/i2c/sun8i_rsb.c b/drivers/i2c/sun8i_rsb.c
> new file mode 100644
> index 00000000000..716b245a003
> --- /dev/null
> +++ b/drivers/i2c/sun8i_rsb.c
> @@ -0,0 +1,281 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * (C) Copyright 2014 Hans de Goede <hdegoede at redhat.com>
> + *
> + * Based on allwinner u-boot sources rsb code which is:
> + * (C) Copyright 2007-2013
> + * Allwinner Technology Co., Ltd. <www.allwinnertech.com>
> + * lixiang <lixiang at allwinnertech.com>
> + */
> +
> +#include <axp_pmic.h>
> +#include <common.h>
> +#include <dm.h>
> +#include <errno.h>
> +#include <i2c.h>
> +#include <time.h>
> +#include <asm/arch/cpu.h>
> +#include <asm/arch/gpio.h>
> +#include <asm/arch/prcm.h>
> +#include <asm/arch/rsb.h>
> +
> +static int sun8i_rsb_await_trans(struct sunxi_rsb_reg *base)
> +{
> +	unsigned long tmo = timer_get_us() + 1000000;
> +	u32 stat;
> +	int ret;
> +
> +	while (1) {
> +		stat = readl(&base->stat);
> +		if (stat & RSB_STAT_LBSY_INT) {
> +			ret = -EBUSY;
> +			break;
> +		}
> +		if (stat & RSB_STAT_TERR_INT) {
> +			ret = -EIO;
> +			break;
> +		}
> +		if (stat & RSB_STAT_TOVER_INT) {
> +			ret = 0;
> +			break;
> +		}
> +		if (timer_get_us() > tmo) {
> +			ret = -ETIME;
> +			break;
> +		}
> +	}
> +	writel(stat, &base->stat); /* Clear status bits */
> +
> +	return ret;
> +}
> +
> +static int sun8i_rsb_do_trans(struct sunxi_rsb_reg *base)
> +{
> +	setbits_le32(&base->ctrl, RSB_CTRL_START_TRANS);
> +
> +	return sun8i_rsb_await_trans(base);
> +}
> +
> +static int sun8i_rsb_read(struct sunxi_rsb_reg *base, u16 runtime_addr,
> +			  u8 reg_addr, u8 *data)
> +{
> +	int ret;
> +
> +	writel(RSB_DEVADDR_RUNTIME_ADDR(runtime_addr), &base->devaddr);
> +	writel(reg_addr, &base->addr);
> +	writel(RSB_CMD_BYTE_READ, &base->cmd);
> +
> +	ret = sun8i_rsb_do_trans(base);
> +	if (ret)
> +		return ret;
> +
> +	*data = readl(&base->data) & 0xff;
> +
> +	return 0;
> +}
> +
> +static int sun8i_rsb_write(struct sunxi_rsb_reg *base, u16 runtime_addr,
> +			   u8 reg_addr, u8 data)
> +{
> +	writel(RSB_DEVADDR_RUNTIME_ADDR(runtime_addr), &base->devaddr);
> +	writel(reg_addr, &base->addr);
> +	writel(data, &base->data);
> +	writel(RSB_CMD_BYTE_WRITE, &base->cmd);
> +
> +	return sun8i_rsb_do_trans(base);
> +}
> +
> +static int sun8i_rsb_set_device_address(struct sunxi_rsb_reg *base,
> +					u16 device_addr, u16 runtime_addr)
> +{
> +	writel(RSB_DEVADDR_RUNTIME_ADDR(runtime_addr) |
> +	       RSB_DEVADDR_DEVICE_ADDR(device_addr), &base->devaddr);
> +	writel(RSB_CMD_SET_RTSADDR, &base->cmd);
> +
> +	return sun8i_rsb_do_trans(base);
> +}
> +
> +static void sun8i_rsb_cfg_io(void)
> +{
> +#ifdef CONFIG_MACH_SUN8I
> +	sunxi_gpio_set_cfgpin(SUNXI_GPL(0), SUN8I_GPL_R_RSB);
> +	sunxi_gpio_set_cfgpin(SUNXI_GPL(1), SUN8I_GPL_R_RSB);
> +	sunxi_gpio_set_pull(SUNXI_GPL(0), 1);
> +	sunxi_gpio_set_pull(SUNXI_GPL(1), 1);
> +	sunxi_gpio_set_drv(SUNXI_GPL(0), 2);
> +	sunxi_gpio_set_drv(SUNXI_GPL(1), 2);
> +#elif defined CONFIG_MACH_SUN9I
> +	sunxi_gpio_set_cfgpin(SUNXI_GPN(0), SUN9I_GPN_R_RSB);
> +	sunxi_gpio_set_cfgpin(SUNXI_GPN(1), SUN9I_GPN_R_RSB);
> +	sunxi_gpio_set_pull(SUNXI_GPN(0), 1);
> +	sunxi_gpio_set_pull(SUNXI_GPN(1), 1);
> +	sunxi_gpio_set_drv(SUNXI_GPN(0), 2);
> +	sunxi_gpio_set_drv(SUNXI_GPN(1), 2);
> +#else
> +#error unsupported MACH_SUNXI
> +#endif
> +}
> +
> +static void sun8i_rsb_set_clk(struct sunxi_rsb_reg *base)
> +{
> +	u32 div = 0;
> +	u32 cd_odly = 0;
> +
> +	/* Source is Hosc24M, set RSB clk to 3Mhz */
> +	div = 24000000 / 3000000 / 2 - 1;
> +	cd_odly = div >> 1;
> +	if (!cd_odly)
> +		cd_odly = 1;
> +
> +	writel((cd_odly << 8) | div, &base->ccr);
> +}
> +
> +static int sun8i_rsb_set_device_mode(struct sunxi_rsb_reg *base)
> +{
> +	unsigned long tmo = timer_get_us() + 1000000;
> +
> +	writel(RSB_DMCR_DEVICE_MODE_START | RSB_DMCR_DEVICE_MODE_DATA,
> +	       &base->dmcr);
> +
> +	while (readl(&base->dmcr) & RSB_DMCR_DEVICE_MODE_START) {
> +		if (timer_get_us() > tmo)
> +			return -ETIME;
> +	}
> +
> +	return sun8i_rsb_await_trans(base);
> +}
> +
> +static int sun8i_rsb_init(struct sunxi_rsb_reg *base)
> +{
> +	/* Enable RSB and PIO clk, and de-assert their resets */
> +	prcm_apb0_enable(PRCM_APB0_GATE_PIO | PRCM_APB0_GATE_RSB);
> +
> +	/* Setup external pins */
> +	sun8i_rsb_cfg_io();
> +
> +	writel(RSB_CTRL_SOFT_RST, &base->ctrl);
> +	sun8i_rsb_set_clk(base);
> +
> +	return sun8i_rsb_set_device_mode(base);
> +}
> +
> +#if IS_ENABLED(CONFIG_AXP_PMIC_BUS)
> +int rsb_read(const u16 runtime_addr, const u8 reg_addr, u8 *data)
> +{
> +	struct sunxi_rsb_reg *base = (struct sunxi_rsb_reg *)SUNXI_RSB_BASE;
> +
> +	return sun8i_rsb_read(base, runtime_addr, reg_addr, data);
> +}
> +
> +int rsb_write(const u16 runtime_addr, const u8 reg_addr, u8 data)
> +{
> +	struct sunxi_rsb_reg *base = (struct sunxi_rsb_reg *)SUNXI_RSB_BASE;
> +
> +	return sun8i_rsb_write(base, runtime_addr, reg_addr, data);
> +}
> +
> +int rsb_set_device_address(u16 device_addr, u16 runtime_addr)
> +{
> +	struct sunxi_rsb_reg *base = (struct sunxi_rsb_reg *)SUNXI_RSB_BASE;
> +
> +	return sun8i_rsb_set_device_address(base, device_addr, runtime_addr);
> +}
> +
> +int rsb_init(void)
> +{
> +	struct sunxi_rsb_reg *base = (struct sunxi_rsb_reg *)SUNXI_RSB_BASE;
> +
> +	return sun8i_rsb_init(base);
> +}
> +#endif
> +
> +#if CONFIG_IS_ENABLED(DM_I2C)
> +struct sun8i_rsb_priv {
> +	struct sunxi_rsb_reg *base;
> +};
> +
> +/*
> + * The mapping from hardware address to runtime address is fixed, and shared
> + * among all RSB drivers. See the comment in drivers/bus/sunxi-rsb.c in Linux.
> + */
> +static int sun8i_rsb_get_runtime_address(u16 device_addr)
> +{
> +	if (device_addr == AXP_PMIC_PRI_DEVICE_ADDR)
> +		return AXP_PMIC_PRI_RUNTIME_ADDR;
> +	if (device_addr == AXP_PMIC_SEC_DEVICE_ADDR)
> +		return AXP_PMIC_SEC_RUNTIME_ADDR;
> +
> +	return -ENXIO;
> +}
> +
> +static int sun8i_rsb_xfer(struct udevice *bus, struct i2c_msg *msg, int nmsgs)
> +{
> +	int runtime_addr = sun8i_rsb_get_runtime_address(msg->addr);
> +	struct sun8i_rsb_priv *priv = dev_get_priv(bus);
> +
> +	if (runtime_addr < 0)
> +		return runtime_addr;
> +
> +	/* The hardware only supports SMBus-style transfers. */
> +	if (nmsgs == 2 && msg[1].flags == I2C_M_RD && msg[1].len == 1)
> +		return sun8i_rsb_read(priv->base, runtime_addr,
> +				      msg[0].buf[0], &msg[1].buf[0]);
> +
> +	if (nmsgs == 1 && msg[0].len == 2)
> +		return sun8i_rsb_write(priv->base, runtime_addr,
> +				       msg[0].buf[0], msg[0].buf[1]);
> +
> +	return -EINVAL;
> +}
> +
> +static int sun8i_rsb_probe_chip(struct udevice *bus, uint chip_addr,
> +				uint chip_flags)
> +{
> +	int runtime_addr = sun8i_rsb_get_runtime_address(chip_addr);
> +	struct sun8i_rsb_priv *priv = dev_get_priv(bus);
> +
> +	if (runtime_addr < 0)
> +		return runtime_addr;
> +
> +	return sun8i_rsb_set_device_address(priv->base, chip_addr, runtime_addr);
> +}
> +
> +static int sun8i_rsb_probe(struct udevice *bus)
> +{
> +	struct sun8i_rsb_priv *priv = dev_get_priv(bus);
> +
> +	priv->base = dev_read_addr_ptr(bus);
> +
> +	return sun8i_rsb_init(priv->base);
> +}
> +
> +static int sun8i_rsb_child_pre_probe(struct udevice *child)
> +{
> +	struct dm_i2c_chip *chip = dev_get_parent_plat(child);
> +
> +	/* Ensure each transfer is for a single register. */
> +	chip->flags |= DM_I2C_CHIP_RD_ADDRESS | DM_I2C_CHIP_WR_ADDRESS;
> +
> +	return 0;
> +}
> +
> +static const struct dm_i2c_ops sun8i_rsb_ops = {
> +	.xfer		= sun8i_rsb_xfer,
> +	.probe_chip	= sun8i_rsb_probe_chip,
> +};
> +
> +static const struct udevice_id sun8i_rsb_ids[] = {
> +	{ .compatible = "allwinner,sun8i-a23-rsb" },
> +	{ /* sentinel */ }
> +};
> +
> +U_BOOT_DRIVER(sun8i_rsb) = {
> +	.name			= "sun8i_rsb",
> +	.id			= UCLASS_I2C,
> +	.of_match		= sun8i_rsb_ids,
> +	.probe			= sun8i_rsb_probe,
> +	.child_pre_probe	= sun8i_rsb_child_pre_probe,
> +	.priv_auto		= sizeof(struct sun8i_rsb_priv),
> +	.ops			= &sun8i_rsb_ops,
> +};
> +#endif /* CONFIG_IS_ENABLED(DM_I2C) */
> diff --git a/include/axp_pmic.h b/include/axp_pmic.h
> index 0db3e143eda..46a017d2efa 100644
> --- a/include/axp_pmic.h
> +++ b/include/axp_pmic.h
> @@ -30,6 +30,12 @@
>  #define AXP_PMIC_MODE_REG		0x3e
>  #define AXP_PMIC_MODE_I2C		0x00
>  #define AXP_PMIC_MODE_P2WI		0x3e
> +#define AXP_PMIC_MODE_RSB		0x7c
> +
> +#define AXP_PMIC_PRI_DEVICE_ADDR	0x3a3
> +#define AXP_PMIC_PRI_RUNTIME_ADDR	0x2d
> +#define AXP_PMIC_SEC_DEVICE_ADDR	0x745
> +#define AXP_PMIC_SEC_RUNTIME_ADDR	0x3a
>  
>  int axp_set_dcdc1(unsigned int mvolt);
>  int axp_set_dcdc2(unsigned int mvolt);



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