Hi Rahul,
Thank you for the patch.
On Wed, Jun 22, 2022 at 01:23:39PM +0530, Rahul T R wrote:
> Add support for band ctrl config for dphy tx.
>
> Signed-off-by: Rahul T R <r-ravikumar@xxxxxx>
> ---
> drivers/phy/cadence/cdns-dphy.c | 52 ++++++++++++++++++++++++++++++++-
> 1 file changed, 51 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/phy/cadence/cdns-dphy.c b/drivers/phy/cadence/cdns-dphy.c
> index ba042e39cfaf..ddfa524d8ce7 100644
> --- a/drivers/phy/cadence/cdns-dphy.c
> +++ b/drivers/phy/cadence/cdns-dphy.c
> @@ -4,6 +4,7 @@
> */
>
> #include <linux/bitops.h>
> +#include <linux/bitfield.h>
Nitpicking, bitfield goes before bitops :-)
> #include <linux/clk.h>
> #include <linux/io.h>
> #include <linux/module.h>
> @@ -45,6 +46,10 @@
> #define DPHY_CMN_OPDIV_FROM_REG BIT(6)
> #define DPHY_CMN_OPDIV(x) ((x) << 7)
>
> +#define DPHY_BAND_CFG DPHY_PCS(0x0)
> +#define DPHY_BAND_CFG_LEFT_BAND GENMASK(4, 0)
> +#define DPHY_BAND_CFG_RIGHT_BAND GENMASK(9, 5)
> +
> #define DPHY_PSM_CFG DPHY_PCS(0x4)
> #define DPHY_PSM_CFG_FROM_REG BIT(0)
> #define DPHY_PSM_CLK_DIV(x) ((x) << 1)
> @@ -92,6 +97,22 @@ struct cdns_dphy {
> struct phy *phy;
> };
>
> +struct cdns_dphy_band {
> + unsigned int min_rate;
> + unsigned int max_rate;
> +};
> +
> +/* Order of bands is important since the index is the band number. */
> +static struct cdns_dphy_band tx_bands[] = {
static const
> + {80, 100}, {100, 120}, {120, 160}, {160, 200}, {200, 240},
> + {240, 320}, {320, 390}, {390, 450}, {450, 510}, {510, 560},
> + {560, 640}, {640, 690}, {690, 770}, {770, 870}, {870, 950},
> + {950, 1000}, {1000, 1200}, {1200, 1400}, {1400, 1600}, {1600, 1800},
> + {1800, 2000}, {2000, 2200}, {2200, 2500}
The max_rate value of band N is always equal to the min_rate value of
band N+1. Could we store one only ?
> +};
> +
> +static int num_tx_bands = ARRAY_SIZE(tx_bands);
You can use ARRAY_SIZE(tx_bands) directly below and drop this.
> +
> static int cdns_dsi_get_dphy_pll_cfg(struct cdns_dphy *dphy,
> struct cdns_dphy_cfg *cfg,
> struct phy_configure_opts_mipi_dphy *opts,
> @@ -232,6 +253,26 @@ static int cdns_dphy_config_from_opts(struct phy *phy,
> return 0;
> }
>
> +static int cdns_dphy_tx_get_band_ctrl(unsigned long hs_clk_rate)
> +{
> + unsigned int rate;
> + int i;
> +
> + rate = hs_clk_rate / 1000000UL;
> +
> + if (rate < tx_bands[0].min_rate || rate >= tx_bands[num_tx_bands - 1].max_rate)
> + return -EOPNOTSUPP;
> +
> + for (i = 0; i < num_tx_bands; i++) {
> + if (rate >= tx_bands[i].min_rate && rate < tx_bands[i].max_rate)
> + return i;
> + }
> +
> + /* Unreachable. */
> + WARN(1, "Reached unreachable code.");
I'd drop the WARN() if it's really unreachable.
> + return -EINVAL;
> +}
> +
> static int cdns_dphy_validate(struct phy *phy, enum phy_mode mode, int submode,
> union phy_configure_opts *opts)
> {
> @@ -247,7 +288,8 @@ static int cdns_dphy_configure(struct phy *phy, union phy_configure_opts *opts)
> {
> struct cdns_dphy *dphy = phy_get_drvdata(phy);
> struct cdns_dphy_cfg cfg = { 0 };
> - int ret;
> + int ret, band_ctrl;
> + unsigned int reg;
>
> ret = cdns_dphy_config_from_opts(phy, &opts->mipi_dphy, &cfg);
> if (ret)
> @@ -276,6 +318,14 @@ static int cdns_dphy_configure(struct phy *phy, union phy_configure_opts *opts)
> */
> cdns_dphy_set_pll_cfg(dphy, &cfg);
>
> + band_ctrl = cdns_dphy_tx_get_band_ctrl(opts->mipi_dphy.hs_clk_rate);
> + if (band_ctrl < 0)
> + return band_ctrl;
> +
> + reg = FIELD_PREP(DPHY_BAND_CFG_LEFT_BAND, band_ctrl) |
> + FIELD_PREP(DPHY_BAND_CFG_RIGHT_BAND, band_ctrl);
> + writel(reg, dphy->regs + DPHY_BAND_CFG);
> +
> return 0;
> }
>
--
Regards,
Laurent Pinchart
