[PATCH 2/2] mmc: host: sunxi: add support for A64 mmc controller
Hans de Goede
hdegoede at redhat.com
Sat Jul 30 03:29:54 PDT 2016
Hi,
On 30-07-16 11:36, Icenowy Zheng wrote:
> A64 SoC features a MMC controller which need only the mod clock, and can
> calibrate delay by itself. This patch adds support for the new MMC
> controller IP core.
>
> Signed-off-by: Icenowy Zheng <icenowy at aosc.xyz>
Cool stuff, thanks for your work on this!
> ---
> drivers/mmc/host/sunxi-mmc.c | 166 +++++++++++++++++++++++++++++++------------
> 1 file changed, 122 insertions(+), 44 deletions(-)
>
> diff --git a/drivers/mmc/host/sunxi-mmc.c b/drivers/mmc/host/sunxi-mmc.c
> index 2ee4c21..ac56bcf 100644
> --- a/drivers/mmc/host/sunxi-mmc.c
> +++ b/drivers/mmc/host/sunxi-mmc.c
> @@ -72,6 +72,14 @@
> #define SDXC_REG_CHDA (0x90)
> #define SDXC_REG_CBDA (0x94)
>
> +/* New registers introduced in A64 */
> +#define SDXC_REG_A12A 0x058 /* SMC Auto Command 12 Register */
> +#define SDXC_REG_SD_NTSR 0x05C /* SMC New Timing Set Register */
> +#define SDXC_REG_DRV_DL 0x140 /* Drive Delay Control Register */
> +#define SDXC_REG_SAMP_DL_REG 0x144 /* SMC sample delay control */
> +#define SDXC_REG_DS_DL_REG 0x148 /* SMC data strobe delay control */
> +
> +
> #define mmc_readl(host, reg) \
> readl((host)->reg_base + SDXC_##reg)
> #define mmc_writel(host, reg, value) \
> @@ -217,6 +225,15 @@
> #define SDXC_CLK_50M_DDR 3
> #define SDXC_CLK_50M_DDR_8BIT 4
>
> +#define SDXC_2X_TIMING_MODE BIT(31)
> +
> +#define SDXC_CAL_START BIT(15)
> +#define SDXC_CAL_DONE BIT(14)
> +#define SDXC_CAL_DL_SHIFT 8
> +#define SDXC_CAL_DL_SW_EN BIT(7)
> +#define SDXC_CAL_DL_SW_SHIFT 0
> +#define SDXC_CAL_DL_MASK 0x3f
> +
> struct sunxi_mmc_clk_delay {
> u32 output;
> u32 sample;
> @@ -261,6 +278,9 @@ struct sunxi_mmc_host {
>
> /* vqmmc */
> bool vqmmc_enabled;
> +
> + /* does the IP block support autocalibration? */
> + bool can_calibrate;
> };
>
> static int sunxi_mmc_reset_host(struct sunxi_mmc_host *host)
> @@ -653,10 +673,66 @@ static int sunxi_mmc_oclk_onoff(struct sunxi_mmc_host *host, u32 oclk_en)
> return 0;
> }
>
> +static int sunxi_mmc_calibrate(struct sunxi_mmc_host *host,
> + struct mmc_ios *ios, int reg_off)
> +{
> + u32 reg = readl(host->reg_base + reg_off);
> + u32 delay;
> +
> + reg &= ~(SDXC_CAL_DL_MASK << SDXC_CAL_DL_SW_SHIFT);
> + reg &= ~SDXC_CAL_DL_SW_EN;
> +
> + writel(reg | SDXC_CAL_START, host->reg_base + reg_off);
> +
> + dev_dbg(mmc_dev(host->mmc), "calibration started\n");
> +
> + while (!((reg = readl(host->reg_base + reg_off)) & SDXC_CAL_DONE))
> + cpu_relax();
> +
> + delay = (reg >> SDXC_CAL_DL_SHIFT) & SDXC_CAL_DL_MASK;
> +
> + reg &= ~SDXC_CAL_START;
> + reg |= (delay << SDXC_CAL_DL_SW_SHIFT) | SDXC_CAL_DL_SW_EN;
> +
> + writel(reg, host->reg_base + reg_off);
> +
> + dev_dbg(mmc_dev(host->mmc), "calibration ended, res is 0x%x\n", reg);
> +
> + return 0;
> +}
> +
> +static int sunxi_mmc_determine_delays(struct sunxi_mmc_host *host,
> + struct mmc_ios *ios, int rate)
> +{
> + int index;
> +
> + if (rate <= 400000) {
> + index = SDXC_CLK_400K;
> + } else if (rate <= 25000000) {
> + index = SDXC_CLK_25M;
> + } else if (rate <= 52000000) {
> + if (ios->timing != MMC_TIMING_UHS_DDR50 &&
> + ios->timing != MMC_TIMING_MMC_DDR52) {
> + index = SDXC_CLK_50M;
> + } else if (ios->bus_width == MMC_BUS_WIDTH_8) {
> + index = SDXC_CLK_50M_DDR_8BIT;
> + } else {
> + index = SDXC_CLK_50M_DDR;
> + }
> + } else {
> + return -EINVAL;
> + }
> +
> + clk_set_phase(host->clk_sample, host->clk_delays[index].sample);
> + clk_set_phase(host->clk_output, host->clk_delays[index].output);
> +
> + return 0;
> +}
> +
The factoring out of this into a function really should be done in
a separate preparation patch, that will also make the patch making
the actual functional changes much easier to read.
Regards,
Hans
> static int sunxi_mmc_clk_set_rate(struct sunxi_mmc_host *host,
> struct mmc_ios *ios)
> {
> - u32 rate, oclk_dly, rval, sclk_dly;
> + u32 rate, rval;
> u32 clock = ios->clock;
> int ret;
>
> @@ -692,32 +768,18 @@ static int sunxi_mmc_clk_set_rate(struct sunxi_mmc_host *host,
> }
> mmc_writel(host, REG_CLKCR, rval);
>
> - /* determine delays */
> - if (rate <= 400000) {
> - oclk_dly = host->clk_delays[SDXC_CLK_400K].output;
> - sclk_dly = host->clk_delays[SDXC_CLK_400K].sample;
> - } else if (rate <= 25000000) {
> - oclk_dly = host->clk_delays[SDXC_CLK_25M].output;
> - sclk_dly = host->clk_delays[SDXC_CLK_25M].sample;
> - } else if (rate <= 52000000) {
> - if (ios->timing != MMC_TIMING_UHS_DDR50 &&
> - ios->timing != MMC_TIMING_MMC_DDR52) {
> - oclk_dly = host->clk_delays[SDXC_CLK_50M].output;
> - sclk_dly = host->clk_delays[SDXC_CLK_50M].sample;
> - } else if (ios->bus_width == MMC_BUS_WIDTH_8) {
> - oclk_dly = host->clk_delays[SDXC_CLK_50M_DDR_8BIT].output;
> - sclk_dly = host->clk_delays[SDXC_CLK_50M_DDR_8BIT].sample;
> - } else {
> - oclk_dly = host->clk_delays[SDXC_CLK_50M_DDR].output;
> - sclk_dly = host->clk_delays[SDXC_CLK_50M_DDR].sample;
> - }
> + if (host->can_calibrate) {
> + ret = sunxi_mmc_calibrate(host, ios, SDXC_REG_SAMP_DL_REG);
> + if (ret)
> + return ret;
> +
> + /* TODO: enable calibrate on sdc2 SDXC_REG_DS_DL_REG of A64 */
> } else {
> - return -EINVAL;
> + ret = sunxi_mmc_determine_delays(host, ios, rate);
> + if (ret)
> + return ret;
> }
>
> - clk_set_phase(host->clk_sample, sclk_dly);
> - clk_set_phase(host->clk_output, oclk_dly);
> -
> return sunxi_mmc_oclk_onoff(host, 1);
> }
>
> @@ -942,6 +1004,7 @@ static const struct of_device_id sunxi_mmc_of_match[] = {
> { .compatible = "allwinner,sun4i-a10-mmc", },
> { .compatible = "allwinner,sun5i-a13-mmc", },
> { .compatible = "allwinner,sun9i-a80-mmc", },
> + { .compatible = "allwinner,sun50i-a64-mmc", },
> { /* sentinel */ }
> };
> MODULE_DEVICE_TABLE(of, sunxi_mmc_of_match);
> @@ -990,6 +1053,11 @@ static int sunxi_mmc_resource_request(struct sunxi_mmc_host *host,
> else
> host->clk_delays = sunxi_mmc_clk_delays;
>
> + if (of_device_is_compatible(np, "allwinner,sun50i-a64-mmc"))
> + host->can_calibrate = true;
> + else
> + host->can_calibrate = false;
> +
> ret = mmc_regulator_get_supply(host->mmc);
> if (ret) {
> if (ret != -EPROBE_DEFER)
> @@ -1014,16 +1082,22 @@ static int sunxi_mmc_resource_request(struct sunxi_mmc_host *host,
> return PTR_ERR(host->clk_mmc);
> }
>
> - host->clk_output = devm_clk_get(&pdev->dev, "output");
> - if (IS_ERR(host->clk_output)) {
> - dev_err(&pdev->dev, "Could not get output clock\n");
> - return PTR_ERR(host->clk_output);
> - }
> + /* self-calibrate version of the IP block needs no output/sample */
> + if (!host->can_calibrate) {
> + host->clk_output = devm_clk_get(&pdev->dev, "output");
> + if (IS_ERR(host->clk_output)) {
> + dev_err(&pdev->dev, "Could not get output clock\n");
> + return PTR_ERR(host->clk_output);
> + }
>
> - host->clk_sample = devm_clk_get(&pdev->dev, "sample");
> - if (IS_ERR(host->clk_sample)) {
> - dev_err(&pdev->dev, "Could not get sample clock\n");
> - return PTR_ERR(host->clk_sample);
> + host->clk_sample = devm_clk_get(&pdev->dev, "sample");
> + if (IS_ERR(host->clk_sample)) {
> + dev_err(&pdev->dev, "Could not get sample clock\n");
> + return PTR_ERR(host->clk_sample);
> + }
> + } else {
> + host->clk_sample = NULL;
> + host->clk_output = NULL;
> }
>
> host->reset = devm_reset_control_get_optional(&pdev->dev, "ahb");
> @@ -1042,16 +1116,18 @@ static int sunxi_mmc_resource_request(struct sunxi_mmc_host *host,
> goto error_disable_clk_ahb;
> }
>
> - ret = clk_prepare_enable(host->clk_output);
> - if (ret) {
> - dev_err(&pdev->dev, "Enable output clk err %d\n", ret);
> - goto error_disable_clk_mmc;
> - }
> + if (!host->can_calibrate) {
> + ret = clk_prepare_enable(host->clk_output);
> + if (ret) {
> + dev_err(&pdev->dev, "Enable output clk err %d\n", ret);
> + goto error_disable_clk_mmc;
> + }
>
> - ret = clk_prepare_enable(host->clk_sample);
> - if (ret) {
> - dev_err(&pdev->dev, "Enable sample clk err %d\n", ret);
> - goto error_disable_clk_output;
> + ret = clk_prepare_enable(host->clk_sample);
> + if (ret) {
> + dev_err(&pdev->dev, "Enable sample clk err %d\n", ret);
> + goto error_disable_clk_output;
> + }
> }
>
> if (!IS_ERR(host->reset)) {
> @@ -1078,9 +1154,11 @@ error_assert_reset:
> if (!IS_ERR(host->reset))
> reset_control_assert(host->reset);
> error_disable_clk_sample:
> - clk_disable_unprepare(host->clk_sample);
> + if (!host->can_calibrate)
> + clk_disable_unprepare(host->clk_sample);
> error_disable_clk_output:
> - clk_disable_unprepare(host->clk_output);
> + if (!host->can_calibrate)
> + clk_disable_unprepare(host->clk_output);
> error_disable_clk_mmc:
> clk_disable_unprepare(host->clk_mmc);
> error_disable_clk_ahb:
>
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