Re: [PATCH 01/11] i2c: Add a DM_I2C wrapper for the sun6i_p2wi controller

[Heiko Schocher <hs@denx.de>]

Hello Samuel,

On 22.08.21 01:05, Samuel Holland 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.
> 
> Since the non-DM bus controller driver is still needed in SPL, the quick
> solution is to implement the DM_I2C ops using the existing functions.
> 
> The register for switching between I2C/P2WI/RSB mode is the same across
> all PMIC variants, so move that to the common header.
> 
> Signed-off-by: Samuel Holland <samuel@sholland.org>
> ---
> 
>  arch/arm/mach-sunxi/Kconfig    | 11 ------
>  arch/arm/mach-sunxi/pmic_bus.c |  7 ++--
>  drivers/i2c/Kconfig            |  8 +++++
>  drivers/i2c/Makefile           |  1 +
>  drivers/i2c/sun6i_p2wi.c       | 66 ++++++++++++++++++++++++++++++++++

I wonder, as this config symbol gets also removed, that there
is no remove of driver code?

>  include/axp_pmic.h             |  6 ++++
>  6 files changed, 84 insertions(+), 15 deletions(-)
>  create mode 100644 drivers/i2c/sun6i_p2wi.c
> 
> diff --git a/arch/arm/mach-sunxi/Kconfig b/arch/arm/mach-sunxi/Kconfig
> index 79c669a4813..37076c2dfb3 100644
> --- a/arch/arm/mach-sunxi/Kconfig
> +++ b/arch/arm/mach-sunxi/Kconfig
> @@ -88,17 +88,6 @@ config DRAM_SUN50I_H616_UNKNOWN_FEATURE
>  	  feature.
>  endif
>  
> -config SUN6I_P2WI
> -	bool "Allwinner sun6i internal P2WI controller"
> -	help
> -	  If you say yes to this option, support will be included for the
> -	  P2WI (Push/Pull 2 Wire Interface) controller embedded in some sunxi
> -	  SOCs.
> -	  The P2WI looks like an SMBus controller (which supports only byte
> -	  accesses), except that it only supports one slave device.
> -	  This interface is used to connect to specific PMIC devices (like the
> -	  AXP221).
> -
>  config SUN6I_PRCM
>  	bool
>  	help
> diff --git a/arch/arm/mach-sunxi/pmic_bus.c b/arch/arm/mach-sunxi/pmic_bus.c
> index 0394ce85644..673a05fdd16 100644
> --- a/arch/arm/mach-sunxi/pmic_bus.c
> +++ b/arch/arm/mach-sunxi/pmic_bus.c
> @@ -8,6 +8,7 @@
>   * axp223 uses the rsb bus, these functions abstract this.
>   */
>  
> +#include <axp_pmic.h>
>  #include <common.h>
>  #include <asm/arch/p2wi.h>
>  #include <asm/arch/rsb.h>
> @@ -21,8 +22,6 @@
>  #define AXP305_I2C_ADDR			0x36
>  
>  #define AXP221_CHIP_ADDR		0x68
> -#define AXP221_CTRL_ADDR		0x3e
> -#define AXP221_INIT_DATA		0x3e
>  
>  /* AXP818 device and runtime addresses are same as AXP223 */
>  #define AXP223_DEVICE_ADDR		0x3a3
> @@ -40,8 +39,8 @@ int pmic_bus_init(void)
>  #if defined CONFIG_AXP221_POWER || defined CONFIG_AXP809_POWER || defined CONFIG_AXP818_POWER
>  # ifdef CONFIG_MACH_SUN6I
>  	p2wi_init();
> -	ret = p2wi_change_to_p2wi_mode(AXP221_CHIP_ADDR, AXP221_CTRL_ADDR,
> -				       AXP221_INIT_DATA);
> +	ret = p2wi_change_to_p2wi_mode(AXP221_CHIP_ADDR, AXP_PMIC_MODE_REG,
> +				       AXP_PMIC_MODE_P2WI);
>  # elif defined CONFIG_MACH_SUN8I_R40
>  	/* Nothing. R40 uses the AXP221s in I2C mode */
>  	ret = 0;
> diff --git a/drivers/i2c/Kconfig b/drivers/i2c/Kconfig
> index 5d27f503bfc..d082676c4b2 100644
> --- a/drivers/i2c/Kconfig
> +++ b/drivers/i2c/Kconfig
> @@ -577,6 +577,14 @@ config SYS_I2C_STM32F7
>  	   _ Optional clock stretching
>  	   _ Software reset
>  
> +config SUN6I_P2WI

Could you please use "SYS_I2C_" ?

> +	bool "Allwinner sun6i P2WI controller"
> +	depends on ARCH_SUNXI
> +	help
> +	  Support for the P2WI (Push/Pull 2 Wire Interface) controller embedded
> +	  in the Allwinner A31 and A31s SOCs. This interface is used to connect
> +	  to specific devices like the X-Powers AXP221 PMIC.
> +
>  config SYNQUACER
>  	bool "Socionext SynQuacer I2C controller"
>  	depends on ARCH_SYNQUACER && DM_I2C
> diff --git a/drivers/i2c/Makefile b/drivers/i2c/Makefile
> index 3a7ecd9274b..2461f0a2db8 100644
> --- a/drivers/i2c/Makefile
> +++ b/drivers/i2c/Makefile
> @@ -43,6 +43,7 @@ obj-$(CONFIG_SYS_I2C_SANDBOX) += sandbox_i2c.o i2c-emul-uclass.o
>  obj-$(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_SUN6I_P2WI) += sun6i_p2wi.o

please sort alphabetical.

>  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/sun6i_p2wi.c b/drivers/i2c/sun6i_p2wi.c
> new file mode 100644
> index 00000000000..f1e8e5ed107
> --- /dev/null
> +++ b/drivers/i2c/sun6i_p2wi.c
> @@ -0,0 +1,66 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +
> +#include <axp_pmic.h>
> +#include <dm.h>
> +#include <i2c.h>
> +#include <asm/arch/p2wi.h>
> +
> +#if CONFIG_IS_ENABLED(DM_I2C)
> +
> +static int sun6i_p2wi_xfer(struct udevice *bus, struct i2c_msg *msg, int nmsgs)
> +{
> +	/* The hardware only supports SMBus-style transfers. */
> +	if (nmsgs == 2 && msg[1].flags == I2C_M_RD && msg[1].len == 1)
> +		return p2wi_read(msg[0].buf[0], msg[1].buf);
> +
> +	if (nmsgs == 1 && msg[0].len == 2)
> +		return p2wi_write(msg[0].buf[0], msg[0].buf[1]);
> +
> +	return -EINVAL;
> +}
> +
> +static int sun6i_p2wi_probe_chip(struct udevice *bus, uint chip_addr,
> +				 uint chip_flags)
> +{
> +	return p2wi_change_to_p2wi_mode(chip_addr,
> +					AXP_PMIC_MODE_REG,
> +					AXP_PMIC_MODE_P2WI);
> +}
> +
> +static int sun6i_p2wi_probe(struct udevice *bus)
> +{
> +	p2wi_init();
> +
> +	return 0;
> +}
> +
> +static int sun6i_p2wi_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 sun6i_p2wi_ops = {
> +	.xfer		= sun6i_p2wi_xfer,
> +	.probe_chip	= sun6i_p2wi_probe_chip,
> +};
> +
> +static const struct udevice_id sun6i_p2wi_ids[] = {
> +	{ .compatible = "allwinner,sun6i-a31-p2wi" },
> +	{ /* sentinel */ }
> +};
> +
> +U_BOOT_DRIVER(sun6i_p2wi) = {
> +	.name			= "sun6i_p2wi",
> +	.id			= UCLASS_I2C,
> +	.of_match		= sun6i_p2wi_ids,
> +	.probe			= sun6i_p2wi_probe,
> +	.child_pre_probe	= sun6i_p2wi_child_pre_probe,
> +	.ops			= &sun6i_p2wi_ops,
> +};
> +
> +#endif /* CONFIG_IS_ENABLED(DM_I2C) */
> diff --git a/include/axp_pmic.h b/include/axp_pmic.h
> index 405044c3a32..0db3e143eda 100644
> --- a/include/axp_pmic.h
> +++ b/include/axp_pmic.h
> @@ -6,6 +6,8 @@
>   */
>  #ifndef _AXP_PMIC_H_
>  
> +#include <stdbool.h>
> +
>  #ifdef CONFIG_AXP152_POWER
>  #include <axp152.h>
>  #endif
> @@ -25,6 +27,10 @@
>  #include <axp818.h>
>  #endif
>  
> +#define AXP_PMIC_MODE_REG		0x3e
> +#define AXP_PMIC_MODE_I2C		0x00
> +#define AXP_PMIC_MODE_P2WI		0x3e
> +
>  int axp_set_dcdc1(unsigned int mvolt);
>  int axp_set_dcdc2(unsigned int mvolt);
>  int axp_set_dcdc3(unsigned int mvolt);
> 

Beside of the nitpicks:
Reviewed-by: Heiko Schocher <hs@denx.de>

Thanks!

bye,
Heiko
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