[PATCH] aspeed: SCU helper functions for I2C.

[Maxim Sloyko]

Ping

On Mon, Oct 3, 2016 at 11:55 AM, <maxims at google.com> wrote:

> From: Maxim Sloyko <maxims at google.com>
>
> SCU helper functions for configuring I2C pins and accessing APB clock.
> ---
>  arch/arm/include/asm/arch-aspeed/ast_scu.h  |  6 +++++
>  arch/arm/include/asm/arch-aspeed/regs-scu.h |  8 ++++++
>  arch/arm/mach-aspeed/ast-scu.c              | 38
> +++++++++++++++++++++++++++++
>  3 files changed, 52 insertions(+)
>
> diff --git a/arch/arm/include/asm/arch-aspeed/ast_scu.h
> b/arch/arm/include/asm/arch-aspeed/ast_scu.h
> index d248416..80ebd6f 100644
> --- a/arch/arm/include/asm/arch-aspeed/ast_scu.h
> +++ b/arch/arm/include/asm/arch-aspeed/ast_scu.h
> @@ -38,6 +38,7 @@ extern void ast_scu_get_who_init_dram(void);
>  extern u32 ast_get_clk_source(void);
>  extern u32 ast_get_h_pll_clk(void);
>  extern u32 ast_get_ahbclk(void);
> +extern u32 ast_get_apbclk(void);
>
>  extern u32 ast_scu_get_vga_memsize(void);
>
> @@ -45,4 +46,9 @@ extern void ast_scu_init_eth(u8 num);
>  extern void ast_scu_multi_func_eth(u8 num);
>  extern void ast_scu_multi_func_romcs(u8 num);
>
> +/* Enable I2C controller and pins for a particular device.
> + * Device numbering starts at 1
> + */
> +extern void ast_scu_enable_i2c(u8 num);
> +
>  #endif
> diff --git a/arch/arm/include/asm/arch-aspeed/regs-scu.h
> b/arch/arm/include/asm/arch-aspeed/regs-scu.h
> index aab032a..4c869c1 100644
> --- a/arch/arm/include/asm/arch-aspeed/regs-scu.h
> +++ b/arch/arm/include/asm/arch-aspeed/regs-scu.h
> @@ -915,6 +915,11 @@
>  #define SCU_FUN_PIN_ROMA4              (0x1 << 18)
>  #define SCU_FUN_PIN_ROMA3              (0x1 << 17)
>  #define SCU_FUN_PIN_ROMA2              (0x1 << 16)
> +/* AST2500 only */
> +#define SCU_FUN_PIN_SDA2               (0x1 << 15)
> +#define SCU_FUN_PIN_SCL2               (0x1 << 14)
> +#define SCU_FUN_PIN_SDA1               (0x1 << 13)
> +#define SCU_FUN_PIN_SCL1               (0x1 << 12)
>
>  /* AST_SCU_FUN_PIN_CTRL9               0xA8 - Multi-function Pin
> Control#9 */
>  #define SCU_FUN_PIN_ROMA21             (0x1 << 3)
> @@ -950,4 +955,7 @@
>  /* AST_SCU_BMC_CLASS                   0x19C - BMC device class code and
> revision ID */
>  /* AST_SCU_BMC_DEV_ID                  0x1A4 - BMC device ID */
>
> +#define SCU_I2C_MIN_BUS_NUM                    (1)
> +#define SCU_I2C_MAX_BUS_NUM                    (14)
> +
>  #endif
> diff --git a/arch/arm/mach-aspeed/ast-scu.c b/arch/arm/mach-aspeed/ast-
> scu.c
> index 280c421..1dbd667 100644
> --- a/arch/arm/mach-aspeed/ast-scu.c
> +++ b/arch/arm/mach-aspeed/ast-scu.c
> @@ -318,6 +318,17 @@ u32 ast_get_ahbclk(void)
>
>  #endif /* AST_SOC_G5 */
>
> +u32 ast_get_apbclk(void)
> +{
> +       u32 h_pll = ast_get_h_pll_clk();
> +       /* The formula for converting the bit pattern to divisor is
> +        * (4 + 4 * DIV), according to datasheet
> +        */
> +       u32 apb_div = 4 + 4 * SCU_GET_PCLK_DIV(ast_scu_read(
> AST_SCU_CLK_SEL));
> +       return h_pll / apb_div;
> +}
> +
> +
>  void ast_scu_show_system_info(void)
>  {
>
> @@ -496,3 +507,30 @@ void ast_scu_get_who_init_dram(void)
>                 break;
>         }
>  }
> +
> +void ast_scu_enable_i2c(u8 bus_num)
> +{
> +       if (bus_num < SCU_I2C_MIN_BUS_NUM || bus_num >
> SCU_I2C_MAX_BUS_NUM) {
> +               debug("%s: bus_num is out of range, must be [%d - %d]\n",
> __func__,
> +                         SCU_I2C_MIN_BUS_NUM, SCU_I2C_MAX_BUS_NUM);
> +               return;
> +       }
> +
> +       /* Enable I2C Controllers */
> +       clrbits_le32(AST_SCU_BASE + AST_SCU_RESET, SCU_RESET_I2C);
> +
> +       if (bus_num >= 3) {
> +               setbits_le32(AST_SCU_BASE + AST_SCU_FUN_PIN_CTRL5,
> +                                        SCU_FUN_PIN_I2C(bus_num));
> +#ifdef AST_SOC_G5
> +       /* In AST2400 aka AST_SOC_G4 SDA{1,2}/SCL{1,2} are fixed function
> pins,
> +        * so no need to change their function. */
> +       } else if (bus_num == 1) {
> +               setbits_le32(AST_SCU_BASE + AST_SCU_FUN_PIN_CTRL8,
> +                                        SCU_FUN_PIN_SDA1 |
> SCU_FUN_PIN_SCL1);
> +       } else if (bus_num == 2) {
> +               setbits_le32(AST_SCU_BASE + AST_SCU_FUN_PIN_CTRL8,
> +                                        SCU_FUN_PIN_SDA2 |
> SCU_FUN_PIN_SCL2);
> +#endif
> +       }
> +}
> --
> 2.8.0.rc3.226.g39d4020
>
>


-- 
*M*axim *S*loyko
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