Re: [PATCH v6] i2c: mt8173: add 4GB mode support in i2c driver.

[Daniel Kurtz]

On Tue, Feb 2, 2016 at 1:19 AM, Liguo Zhang <liguo.zhang@xxxxxxxxxxxx> wrote:
>
> If 4GB mode is enable, we should add 4gb mode support in i2c driver.
> Set 4GB mode register to support 4GB mode.
>
> Signed-off-by: Liguo Zhang <liguo.zhang@xxxxxxxxxxxx>

Reviewed-by: Daniel Kurtz <djkurtz@xxxxxxxxxxxx>


>
> ---
> change in v6:
> Remove unnecessary init for reg_4g_mode.
> change in v5:
> Use BIT_ULL() to fix kernel building warning.
> change in v4:
> Use BIT_ULL() to fix kernel building warning.
> change in v3:
> Only inline the computation of reg_4g_mode in mtk_i2c_set_4g_mode().
> change in v2:
> Define a static inline function mtk_i2c_set_4g_mode() for support 4g mode.
> ---
>  drivers/i2c/busses/i2c-mt65xx.c | 42 +++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 42 insertions(+)
>
> diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c
> index aec8e6c..453358b 100644
> --- a/drivers/i2c/busses/i2c-mt65xx.c
> +++ b/drivers/i2c/busses/i2c-mt65xx.c
> @@ -60,6 +60,7 @@
>  #define I2C_DMA_INT_FLAG_NONE          0x0000
>  #define I2C_DMA_CLR_FLAG               0x0000
>  #define I2C_DMA_HARD_RST               0x0002
> +#define I2C_DMA_4G_MODE                        0x0001
>
>  #define I2C_DEFAULT_SPEED              100000  /* hz */
>  #define MAX_FS_MODE_SPEED              400000
> @@ -88,6 +89,8 @@ enum DMA_REGS_OFFSET {
>         OFFSET_RX_MEM_ADDR = 0x20,
>         OFFSET_TX_LEN = 0x24,
>         OFFSET_RX_LEN = 0x28,
> +       OFFSET_TX_4G_MODE = 0x54,
> +       OFFSET_RX_4G_MODE = 0x58,
>  };
>
>  enum i2c_trans_st_rs {
> @@ -133,6 +136,7 @@ struct mtk_i2c_compatible {
>         unsigned char dcm: 1;
>         unsigned char auto_restart: 1;
>         unsigned char aux_len_reg: 1;
> +       unsigned char support_33bits: 1;
>  };
>
>  struct mtk_i2c {
> @@ -182,6 +186,7 @@ static const struct mtk_i2c_compatible mt6577_compat = {
>         .dcm = 1,
>         .auto_restart = 0,
>         .aux_len_reg = 0,
> +       .support_33bits = 0,
>  };
>
>  static const struct mtk_i2c_compatible mt6589_compat = {
> @@ -190,6 +195,7 @@ static const struct mtk_i2c_compatible mt6589_compat = {
>         .dcm = 0,
>         .auto_restart = 0,
>         .aux_len_reg = 0,
> +       .support_33bits = 0,
>  };
>
>  static const struct mtk_i2c_compatible mt8173_compat = {
> @@ -198,6 +204,7 @@ static const struct mtk_i2c_compatible mt8173_compat = {
>         .dcm = 1,
>         .auto_restart = 1,
>         .aux_len_reg = 1,
> +       .support_33bits = 1,
>  };
>
>  static const struct of_device_id mtk_i2c_of_match[] = {
> @@ -366,6 +373,11 @@ static int mtk_i2c_set_speed(struct mtk_i2c *i2c, unsigned int parent_clk,
>         return 0;
>  }
>
> +static inline u32 mtk_i2c_set_4g_mode(dma_addr_t addr)
> +{
> +       return (addr & BIT_ULL(32)) ? I2C_DMA_4G_MODE : I2C_DMA_CLR_FLAG;
> +}
> +
>  static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs,
>                                int num, int left_num)
>  {
> @@ -373,6 +385,7 @@ static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs,
>         u16 start_reg;
>         u16 control_reg;
>         u16 restart_flag = 0;
> +       u32 reg_4g_mode;
>         dma_addr_t rpaddr = 0;
>         dma_addr_t wpaddr = 0;
>         int ret;
> @@ -439,6 +452,12 @@ static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs,
>                                         msgs->len, DMA_FROM_DEVICE);
>                 if (dma_mapping_error(i2c->dev, rpaddr))
>                         return -ENOMEM;
> +
> +               if (i2c->dev_comp->support_33bits) {
> +                       reg_4g_mode = mtk_i2c_set_4g_mode(rpaddr);
> +                       writel(reg_4g_mode, i2c->pdmabase + OFFSET_RX_4G_MODE);
> +               }
> +
>                 writel((u32)rpaddr, i2c->pdmabase + OFFSET_RX_MEM_ADDR);
>                 writel(msgs->len, i2c->pdmabase + OFFSET_RX_LEN);
>         } else if (i2c->op == I2C_MASTER_WR) {
> @@ -448,6 +467,12 @@ static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs,
>                                         msgs->len, DMA_TO_DEVICE);
>                 if (dma_mapping_error(i2c->dev, wpaddr))
>                         return -ENOMEM;
> +
> +               if (i2c->dev_comp->support_33bits) {
> +                       reg_4g_mode = mtk_i2c_set_4g_mode(wpaddr);
> +                       writel(reg_4g_mode, i2c->pdmabase + OFFSET_TX_4G_MODE);
> +               }
> +
>                 writel((u32)wpaddr, i2c->pdmabase + OFFSET_TX_MEM_ADDR);
>                 writel(msgs->len, i2c->pdmabase + OFFSET_TX_LEN);
>         } else {
> @@ -465,6 +490,15 @@ static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs,
>                                          msgs->len, DMA_TO_DEVICE);
>                         return -ENOMEM;
>                 }
> +
> +               if (i2c->dev_comp->support_33bits) {
> +                       reg_4g_mode = mtk_i2c_set_4g_mode(wpaddr);
> +                       writel(reg_4g_mode, i2c->pdmabase + OFFSET_TX_4G_MODE);
> +
> +                       reg_4g_mode = mtk_i2c_set_4g_mode(rpaddr);
> +                       writel(reg_4g_mode, i2c->pdmabase + OFFSET_RX_4G_MODE);
> +               }
> +
>                 writel((u32)wpaddr, i2c->pdmabase + OFFSET_TX_MEM_ADDR);
>                 writel((u32)rpaddr, i2c->pdmabase + OFFSET_RX_MEM_ADDR);
>                 writel(msgs->len, i2c->pdmabase + OFFSET_TX_LEN);
> @@ -729,6 +763,14 @@ static int mtk_i2c_probe(struct platform_device *pdev)
>                 return -EINVAL;
>         }
>
> +       if (i2c->dev_comp->support_33bits) {
> +               ret = dma_set_mask(&pdev->dev, DMA_BIT_MASK(33));
> +               if (ret) {
> +                       dev_err(&pdev->dev, "dma_set_mask return error.\n");
> +                       return ret;
> +               }
> +       }
> +
>         ret = mtk_i2c_clock_enable(i2c);
>         if (ret) {
>                 dev_err(&pdev->dev, "clock enable failed!\n");
> --
> 1.8.1.1.dirty
>