Hello,

On 10/23/20 2:45 PM, Paul Kocialkowski wrote:
> The Allwinner A31 D-PHY supports both Rx and Tx modes. While the latter
> is already supported and used for MIPI DSI this adds support for the
> former, to be used with MIPI CSI-2.
> 
> This implementation is inspired by the Allwinner BSP implementation.
> 
> Signed-off-by: Paul Kocialkowski <paul.kocialkow...@bootlin.com>
> ---
>  drivers/phy/allwinner/phy-sun6i-mipi-dphy.c | 164 +++++++++++++++++++-
>  1 file changed, 160 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/phy/allwinner/phy-sun6i-mipi-dphy.c 
> b/drivers/phy/allwinner/phy-sun6i-mipi-dphy.c
> index 1fa761ba6cbb..8bcd4bb79f60 100644
> --- a/drivers/phy/allwinner/phy-sun6i-mipi-dphy.c
> +++ b/drivers/phy/allwinner/phy-sun6i-mipi-dphy.c
> @@ -24,6 +24,14 @@
>  #define SUN6I_DPHY_TX_CTL_REG                0x04
>  #define SUN6I_DPHY_TX_CTL_HS_TX_CLK_CONT     BIT(28)
>  
> +#define SUN6I_DPHY_RX_CTL_REG                0x08
> +#define SUN6I_DPHY_RX_CTL_EN_DBC     BIT(31)
> +#define SUN6I_DPHY_RX_CTL_RX_CLK_FORCE       BIT(24)
> +#define SUN6I_DPHY_RX_CTL_RX_D3_FORCE        BIT(23)
> +#define SUN6I_DPHY_RX_CTL_RX_D2_FORCE        BIT(22)
> +#define SUN6I_DPHY_RX_CTL_RX_D1_FORCE        BIT(21)
> +#define SUN6I_DPHY_RX_CTL_RX_D0_FORCE        BIT(20)
> +
>  #define SUN6I_DPHY_TX_TIME0_REG              0x10
>  #define SUN6I_DPHY_TX_TIME0_HS_TRAIL(n)              (((n) & 0xff) << 24)
>  #define SUN6I_DPHY_TX_TIME0_HS_PREPARE(n)    (((n) & 0xff) << 16)
> @@ -44,12 +52,29 @@
>  #define SUN6I_DPHY_TX_TIME4_HS_TX_ANA1(n)    (((n) & 0xff) << 8)
>  #define SUN6I_DPHY_TX_TIME4_HS_TX_ANA0(n)    ((n) & 0xff)
>  
> +#define SUN6I_DPHY_RX_TIME0_REG              0x30
> +#define SUN6I_DPHY_RX_TIME0_HS_RX_SYNC(n)    (((n) & 0xff) << 24)
> +#define SUN6I_DPHY_RX_TIME0_HS_RX_CLK_MISS(n)        (((n) & 0xff) << 16)
> +#define SUN6I_DPHY_RX_TIME0_LP_RX(n)         (((n) & 0xff) << 8)
> +
> +#define SUN6I_DPHY_RX_TIME1_REG              0x34
> +#define SUN6I_DPHY_RX_TIME1_RX_DLY(n)                (((n) & 0xfff) << 20)
> +#define SUN6I_DPHY_RX_TIME1_LP_RX_ULPS_WP(n) ((n) & 0xfffff)
> +
> +#define SUN6I_DPHY_RX_TIME2_REG              0x38
> +#define SUN6I_DPHY_RX_TIME2_HS_RX_ANA1(n)    (((n) & 0xff) << 8)
> +#define SUN6I_DPHY_RX_TIME2_HS_RX_ANA0(n)    ((n) & 0xff)
> +
> +#define SUN6I_DPHY_RX_TIME3_REG              0x40
> +#define SUN6I_DPHY_RX_TIME3_LPRST_DLY(n)     (((n) & 0xffff) << 16)
> +
>  #define SUN6I_DPHY_ANA0_REG          0x4c
>  #define SUN6I_DPHY_ANA0_REG_PWS                      BIT(31)
>  #define SUN6I_DPHY_ANA0_REG_DMPC             BIT(28)
>  #define SUN6I_DPHY_ANA0_REG_DMPD(n)          (((n) & 0xf) << 24)
>  #define SUN6I_DPHY_ANA0_REG_SLV(n)           (((n) & 7) << 12)
>  #define SUN6I_DPHY_ANA0_REG_DEN(n)           (((n) & 0xf) << 8)
> +#define SUN6I_DPHY_ANA0_REG_SFB(n)           (((n) & 3) << 2)
>  
>  #define SUN6I_DPHY_ANA1_REG          0x50
>  #define SUN6I_DPHY_ANA1_REG_VTTMODE          BIT(31)
> @@ -92,6 +117,8 @@ struct sun6i_dphy {
>  
>       struct phy                              *phy;
>       struct phy_configure_opts_mipi_dphy     config;
> +
> +     int                                     submode;
>  };
>  
>  static int sun6i_dphy_init(struct phy *phy)
> @@ -105,6 +132,18 @@ static int sun6i_dphy_init(struct phy *phy)
>       return 0;
>  }
>  
> +static int sun6i_dphy_set_mode(struct phy *phy, enum phy_mode mode, int 
> submode)
> +{
> +     struct sun6i_dphy *dphy = phy_get_drvdata(phy);
> +
> +     if (mode != PHY_MODE_MIPI_DPHY)
> +             return -EINVAL;
> +
> +     dphy->submode = submode;

Shouldn't you check if the submode is valid here?

> +
> +     return 0;
> +}
> +
>  static int sun6i_dphy_configure(struct phy *phy, union phy_configure_opts 
> *opts)
>  {
>       struct sun6i_dphy *dphy = phy_get_drvdata(phy);
> @@ -119,9 +158,8 @@ static int sun6i_dphy_configure(struct phy *phy, union 
> phy_configure_opts *opts)
>       return 0;
>  }
>  
> -static int sun6i_dphy_power_on(struct phy *phy)
> +static int sun6i_dphy_tx_power_on(struct sun6i_dphy *dphy)
>  {
> -     struct sun6i_dphy *dphy = phy_get_drvdata(phy);
>       u8 lanes_mask = GENMASK(dphy->config.lanes - 1, 0);
>  
>       regmap_write(dphy->regs, SUN6I_DPHY_TX_CTL_REG,
> @@ -211,12 +249,129 @@ static int sun6i_dphy_power_on(struct phy *phy)
>       return 0;
>  }
>  
> +static int sun6i_dphy_rx_power_on(struct sun6i_dphy *dphy)
> +{
> +     /* Physical clock rate is actually half of symbol rate with DDR. */
> +     unsigned long mipi_symbol_rate = dphy->config.hs_clk_rate;
> +     unsigned long dphy_clk_rate;
> +     unsigned int rx_dly;
> +     unsigned int lprst_dly;
> +     u32 value;
> +
> +     dphy_clk_rate = clk_get_rate(dphy->mod_clk);
> +     if (!dphy_clk_rate)
> +             return -1;
> +
> +     /* Hardcoded timing parameters from the Allwinner BSP. */
> +     regmap_write(dphy->regs, SUN6I_DPHY_RX_TIME0_REG,
> +                  SUN6I_DPHY_RX_TIME0_HS_RX_SYNC(255) |
> +                  SUN6I_DPHY_RX_TIME0_HS_RX_CLK_MISS(255) |
> +                  SUN6I_DPHY_RX_TIME0_LP_RX(255));
> +
> +     /*
> +      * Formula from the Allwinner BSP, with hardcoded coefficients
> +      * (probably internal divider/multiplier).
> +      */
> +     rx_dly = 8 * (unsigned int)(dphy_clk_rate / (mipi_symbol_rate / 8));
> +
> +     /*
> +      * The Allwinner BSP has an alternative formula for LP_RX_ULPS_WP:
> +      * lp_ulps_wp_cnt = lp_ulps_wp_ms * lp_clk / 1000
> +      * but does not use it and hardcodes 255 instead.
> +      */
> +     regmap_write(dphy->regs, SUN6I_DPHY_RX_TIME1_REG,
> +                  SUN6I_DPHY_RX_TIME1_RX_DLY(rx_dly) |
> +                  SUN6I_DPHY_RX_TIME1_LP_RX_ULPS_WP(255));
> +
> +     /* HS_RX_ANA0 value is hardcoded in the Allwinner BSP. */
> +     regmap_write(dphy->regs, SUN6I_DPHY_RX_TIME2_REG,
> +                  SUN6I_DPHY_RX_TIME2_HS_RX_ANA0(4));
> +
> +     /*
> +      * Formula from the Allwinner BSP, with hardcoded coefficients
> +      * (probably internal divider/multiplier).
> +      */
> +     lprst_dly = 4 * (unsigned int)(dphy_clk_rate / (mipi_symbol_rate / 2));
> +
> +     regmap_write(dphy->regs, SUN6I_DPHY_RX_TIME3_REG,
> +                  SUN6I_DPHY_RX_TIME3_LPRST_DLY(lprst_dly));
> +
> +     /* Analog parameters are hardcoded in the Allwinner BSP. */
> +     regmap_write(dphy->regs, SUN6I_DPHY_ANA0_REG,
> +                  SUN6I_DPHY_ANA0_REG_PWS |
> +                  SUN6I_DPHY_ANA0_REG_SLV(7) |
> +                  SUN6I_DPHY_ANA0_REG_SFB(2));
> +
> +     regmap_write(dphy->regs, SUN6I_DPHY_ANA1_REG,
> +                  SUN6I_DPHY_ANA1_REG_SVTT(4));
> +
> +     regmap_write(dphy->regs, SUN6I_DPHY_ANA4_REG,
> +                  SUN6I_DPHY_ANA4_REG_DMPLVC |
> +                  SUN6I_DPHY_ANA4_REG_DMPLVD(1));
> +
> +     regmap_write(dphy->regs, SUN6I_DPHY_ANA2_REG,
> +                  SUN6I_DPHY_ANA2_REG_ENIB);
> +
> +     regmap_write(dphy->regs, SUN6I_DPHY_ANA3_REG,
> +                  SUN6I_DPHY_ANA3_EN_LDOR |
> +                  SUN6I_DPHY_ANA3_EN_LDOC |
> +                  SUN6I_DPHY_ANA3_EN_LDOD);
> +
> +     /*
> +      * Delay comes from the Allwinner BSP, likely for internal regulator
> +      * ramp-up.
> +      */
> +     udelay(3);
> +
> +     value = SUN6I_DPHY_RX_CTL_EN_DBC | SUN6I_DPHY_RX_CTL_RX_CLK_FORCE;
> +
> +     /*
> +      * Rx data lane force-enable bits are used as regular RX enable by the
> +      * Allwinner BSP.
> +      */
> +     if (dphy->config.lanes >= 1)
> +             value |= SUN6I_DPHY_RX_CTL_RX_D0_FORCE;
> +     if (dphy->config.lanes >= 2)
> +             value |= SUN6I_DPHY_RX_CTL_RX_D1_FORCE;
> +     if (dphy->config.lanes >= 3)
> +             value |= SUN6I_DPHY_RX_CTL_RX_D2_FORCE;
> +     if (dphy->config.lanes == 4)
> +             value |= SUN6I_DPHY_RX_CTL_RX_D3_FORCE;

I would replace this by a switch case with fallthrough to avoid too many 
comparisons
to the same value.

Regards,
Helen

> +
> +     regmap_write(dphy->regs, SUN6I_DPHY_RX_CTL_REG, value);
> +
> +     regmap_write(dphy->regs, SUN6I_DPHY_GCTL_REG,
> +                  SUN6I_DPHY_GCTL_LANE_NUM(dphy->config.lanes) |
> +                  SUN6I_DPHY_GCTL_EN);
> +
> +     return 0;
> +}
> +
> +static int sun6i_dphy_power_on(struct phy *phy)
> +{
> +     struct sun6i_dphy *dphy = phy_get_drvdata(phy);
> +
> +     switch (dphy->submode) {
> +     case PHY_MIPI_DPHY_SUBMODE_TX:
> +             return sun6i_dphy_tx_power_on(dphy);
> +     case PHY_MIPI_DPHY_SUBMODE_RX:
> +             return sun6i_dphy_rx_power_on(dphy);
> +     default:
> +             return -EINVAL;
> +     }
> +}
> +
>  static int sun6i_dphy_power_off(struct phy *phy)
>  {
>       struct sun6i_dphy *dphy = phy_get_drvdata(phy);
>  
> -     regmap_update_bits(dphy->regs, SUN6I_DPHY_ANA1_REG,
> -                        SUN6I_DPHY_ANA1_REG_VTTMODE, 0);
> +     regmap_write(dphy->regs, SUN6I_DPHY_GCTL_REG, 0);
> +
> +     regmap_write(dphy->regs, SUN6I_DPHY_ANA0_REG, 0);
> +     regmap_write(dphy->regs, SUN6I_DPHY_ANA1_REG, 0);
> +     regmap_write(dphy->regs, SUN6I_DPHY_ANA2_REG, 0);
> +     regmap_write(dphy->regs, SUN6I_DPHY_ANA3_REG, 0);
> +     regmap_write(dphy->regs, SUN6I_DPHY_ANA4_REG, 0);
>  
>       return 0;
>  }
> @@ -234,6 +389,7 @@ static int sun6i_dphy_exit(struct phy *phy)
>  
>  
>  static const struct phy_ops sun6i_dphy_ops = {
> +     .set_mode       = sun6i_dphy_set_mode,
>       .configure      = sun6i_dphy_configure,
>       .power_on       = sun6i_dphy_power_on,
>       .power_off      = sun6i_dphy_power_off,
> 
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