On Tue, Dec 08, 2020 at 06:37:41AM -0600, Sanjay R Mehta wrote:
> From: Sanjay R Mehta <Sanju.Mehta@xxxxxxx>
>
> Latest amdgpu card has USB Type-C interface. There is a Type-C controller
> which can be accessed over I2C.
>
> This driver adds I2C bus driver to communicate with Type-C controller. I2C
> client driver will be part of USB Type-C UCSI driver.
>
> Signed-off-by: Sanjay R Mehta <Sanju.Mehta@xxxxxxx>
> Signed-off-by: Nehal Bakulchandra Shah <Nehal-Bakulchandra.Shah@xxxxxxx>
> ---
>
> Changes in v2:
>
> - converted the code to use regmap, read_poll_timeout and made some cosmetic
> changes as suggested by Andy Shevchenko.
> ---
> MAINTAINERS | 7 +
> drivers/i2c/busses/Kconfig | 9 +
> drivers/i2c/busses/Makefile | 1 +
> drivers/i2c/busses/i2c-amdgpu-navi.c | 345 +++++++++++++++++++++++++++
> 4 files changed, 362 insertions(+)
> create mode 100644 drivers/i2c/busses/i2c-amdgpu-navi.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 190c7fa2ea01..93894459a4c8 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -8119,6 +8119,13 @@ L: linux-acpi@xxxxxxxxxxxxxxx
> S: Maintained
> F: drivers/i2c/i2c-core-acpi.c
>
> +I2C CONTROLLER DRIVER FOR AMD GPU
> +M: Nehal Bakulchandra Shah <Nehal-Bakulchandra.Shah@xxxxxxx>
> +M: Sanjay R Mehta <sanju.mehta@xxxxxxx>
> +L: linux-i2c@xxxxxxxxxxxxxxx
> +S: Maintained
> +F: drivers/i2c/busses/i2c-amdgpu-navi.*
> +
> I2C CONTROLLER DRIVER FOR NVIDIA GPU
> M: Ajay Gupta <ajayg@xxxxxxxxxx>
> L: linux-i2c@xxxxxxxxxxxxxxx
> diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
> index 293e7a0760e7..0ff369c0f41f 100644
> --- a/drivers/i2c/busses/Kconfig
> +++ b/drivers/i2c/busses/Kconfig
> @@ -88,6 +88,15 @@ config I2C_AMD_MP2
> This driver can also be built as modules. If so, the modules will
> be called i2c-amd-mp2-pci and i2c-amd-mp2-plat.
>
> +config I2C_AMDGPU_NAVI
> + tristate "AMDGPU NAVI I2C controller"
> + depends on PCI
> + help
> + If you say yes to this option, support will be included for the
> + NAVI I2C controller which is used to communicate with the GPU's
> + Type-C controller. This driver can also be built as a module called
> + i2c-amdgpu-navi.
> +
> config I2C_HIX5HD2
> tristate "Hix5hd2 high-speed I2C driver"
> depends on ARCH_HISI || ARCH_HIX5HD2 || COMPILE_TEST
> diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
> index 19aff0e45cb5..f599473a8ad9 100644
> --- a/drivers/i2c/busses/Makefile
> +++ b/drivers/i2c/busses/Makefile
> @@ -13,6 +13,7 @@ obj-$(CONFIG_I2C_ALI15X3) += i2c-ali15x3.o
> obj-$(CONFIG_I2C_AMD756) += i2c-amd756.o
> obj-$(CONFIG_I2C_AMD756_S4882) += i2c-amd756-s4882.o
> obj-$(CONFIG_I2C_AMD8111) += i2c-amd8111.o
> +obj-$(CONFIG_I2C_AMDGPU_NAVI) += i2c-amdgpu-navi.o
> obj-$(CONFIG_I2C_CHT_WC) += i2c-cht-wc.o
> obj-$(CONFIG_I2C_I801) += i2c-i801.o
> obj-$(CONFIG_I2C_ISCH) += i2c-isch.o
> diff --git a/drivers/i2c/busses/i2c-amdgpu-navi.c b/drivers/i2c/busses/i2c-amdgpu-navi.c
> new file mode 100644
> index 000000000000..3922b8aebc26
> --- /dev/null
> +++ b/drivers/i2c/busses/i2c-amdgpu-navi.c
> @@ -0,0 +1,345 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +//
> +// AMD I2C Controller Driver for Navi GPU's
> +//
> +// Copyright (c) 2020, Advanced Micro Devices, Inc.
> +//
> +// Authors:
> +// Nehal Bakulchandra Shah <Nehal-Bakulchandra.Shah@xxxxxxx>
> +// Sanjay R Mehta <Sanju.Mehta@xxxxxxx>
> +
> +#include <linux/bits.h>
> +#include <linux/delay.h>
> +#include <linux/i2c.h>
> +#include <linux/interrupt.h>
> +#include <linux/module.h>
> +#include <linux/pci.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm.h>
> +#include <linux/regmap.h>
> +#include <asm/unaligned.h>
> +#include "i2c-designware-core.h"
> +
> +#define AMD_UCSI_INTR_EN 0xD
> +#define AMD_UCSI_INTR_REG 0x474
> +#define AMD_MASTERCFG_MASK GENMASK(15, 0)
> +
> +struct amdgpu_i2c_dev {
> + void __iomem *regs;
> + struct regmap *map;
> + struct device *dev;
> + u32 master_cfg;
> + u32 slave_adr;
> + u32 tx_fifo_depth;
> + u32 rx_fifo_depth;
> + u16 ss_hcnt;
> + u16 ss_lcnt;
> + struct i2c_adapter adapter;
> + struct i2c_board_info *gpu_ccgx_ucsi;
> + struct i2c_client *ccgx_client;
> +};
> +
> +static int amdgpu_i2c_read(void *context, unsigned int reg, unsigned int *val)
> +{
> + struct amdgpu_i2c_dev *i2cd = context;
> +
> + *val = readl_relaxed(i2cd->regs + reg);
It's quite confusing calling it "i2c_read" function. What is more
important - why do you need it? It's a simple MMIO on PCI, so why regmap
MMIO cannot be used?
Best regards,
Krzysztof
