Re: [PATCH V2 2/3] mmc: sdhci-pci-gli: Set SDR104's clock to 205MHz and enable SSC for GL9767

[Adrian Hunter <adrian.hunter@intel.com>]

On 30/05/23 12:53, Victor Shih wrote:
> From: Victor Shih <victor.shih@genesyslogic.com.tw>
> 
> Set GL9767 SDR104's clock to 205MHz and enable SSC feature
> depend on register 0x888 BIT(1).
> 
> Signed-off-by: Ben Chuang <ben.chuang@genesyslogic.com.tw>
> Signed-off-by: Victor Shih <victor.shih@genesyslogic.com.tw>
> ---
>  drivers/mmc/host/sdhci-pci-gli.c | 135 ++++++++++++++++++++++++++++++-
>  1 file changed, 134 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/mmc/host/sdhci-pci-gli.c b/drivers/mmc/host/sdhci-pci-gli.c
> index 3ed207b89d1a..178253a7e86f 100644
> --- a/drivers/mmc/host/sdhci-pci-gli.c
> +++ b/drivers/mmc/host/sdhci-pci-gli.c
> @@ -158,6 +158,12 @@
>  #define   GLI_9767_VHS_REV_M	  0x1
>  #define   GLI_9767_VHS_REV_W	  0x2
>  
> +#define PCIE_GLI_9767_COM_MAILBOX		0x888
> +#define   PCIE_GLI_9767_COM_MAILBOX_SSC_EN	  BIT(1)
> +
> +#define PCIE_GLI_9767_CFG		0x8A0
> +#define   PCIE_GLI_9767_CFG_LOW_PWR_OFF	  BIT(12)
> +
>  #define PCIE_GLI_9767_PWR_MACRO_CTL					0x8D0
>  #define   PCIE_GLI_9767_PWR_MACRO_CTL_LOW_VOLTAGE			  GENMASK(3, 0)
>  #define   PCIE_GLI_9767_PWR_MACRO_CTL_LD0_LOW_OUTPUT_VOLTAGE		  GENMASK(15, 12)
> @@ -175,6 +181,16 @@
>  #define   PCIE_GLI_9767_SCR_CORE_PWR_D3_OFF		  BIT(21)
>  #define   PCIE_GLI_9767_SCR_CFG_RST_DATA_LINK_DOWN	  BIT(30)
>  
> +#define PCIE_GLI_9767_SD_PLL_CTL			0x938
> +#define   PCIE_GLI_9767_SD_PLL_CTL_PLL_LDIV		  GENMASK(9, 0)
> +#define   PCIE_GLI_9767_SD_PLL_CTL_PLL_PDIV		  GENMASK(15, 12)
> +#define   PCIE_GLI_9767_SD_PLL_CTL_PLL_DIR_EN		  BIT(16)
> +#define   PCIE_GLI_9767_SD_PLL_CTL_SSC_EN		  BIT(19)
> +#define   PCIE_GLI_9767_SD_PLL_CTL_SSC_STEP_SETTING	  GENMASK(28, 24)
> +
> +#define PCIE_GLI_9767_SD_PLL_CTL2		0x93C
> +#define   PCIE_GLI_9767_SD_PLL_CTL2_PLLSSC_PPM	  GENMASK(31, 16)
> +
>  #define GLI_MAX_TUNING_LOOP 40
>  
>  /* Genesys Logic chipset */
> @@ -753,6 +769,123 @@ static inline void gl9767_vhs_write(struct pci_dev *pdev)
>  	pci_write_config_dword(pdev, PCIE_GLI_9767_VHS, vhs_value);
>  }
>  
> +static bool gl9767_ssc_enable(struct pci_dev *pdev)
> +{
> +	u32 value;
> +	u8 enable;
> +
> +	gl9767_vhs_write(pdev);
> +
> +	pci_read_config_dword(pdev, PCIE_GLI_9767_COM_MAILBOX, &value);
> +	enable = FIELD_GET(PCIE_GLI_9767_COM_MAILBOX_SSC_EN, value);
> +
> +	gl9767_vhs_read(pdev);
> +
> +	return enable;
> +}
> +
> +static void gl9767_set_ssc(struct pci_dev *pdev, u8 enable, u8 step, u16 ppm)
> +{
> +	u32 pll;
> +	u32 ssc;
> +
> +	gl9767_vhs_write(pdev);
> +
> +	pci_read_config_dword(pdev, PCIE_GLI_9767_SD_PLL_CTL, &pll);
> +	pci_read_config_dword(pdev, PCIE_GLI_9767_SD_PLL_CTL2, &ssc);
> +	pll &= ~(PCIE_GLI_9767_SD_PLL_CTL_SSC_STEP_SETTING |
> +		 PCIE_GLI_9767_SD_PLL_CTL_SSC_EN);
> +	ssc &= ~PCIE_GLI_9767_SD_PLL_CTL2_PLLSSC_PPM;
> +	pll |= FIELD_PREP(PCIE_GLI_9767_SD_PLL_CTL_SSC_STEP_SETTING, step) |
> +	       FIELD_PREP(PCIE_GLI_9767_SD_PLL_CTL_SSC_EN, enable);
> +	ssc |= FIELD_PREP(PCIE_GLI_9767_SD_PLL_CTL2_PLLSSC_PPM, ppm);
> +	pci_write_config_dword(pdev, PCIE_GLI_9767_SD_PLL_CTL2, ssc);
> +	pci_write_config_dword(pdev, PCIE_GLI_9767_SD_PLL_CTL, pll);
> +
> +	gl9767_vhs_read(pdev);
> +}
> +
> +static void gl9767_set_pll(struct pci_dev *pdev, u8 dir, u16 ldiv, u8 pdiv)
> +{
> +	u32 pll;
> +
> +	gl9767_vhs_write(pdev);
> +
> +	pci_read_config_dword(pdev, PCIE_GLI_9767_SD_PLL_CTL, &pll);
> +	pll &= ~(PCIE_GLI_9767_SD_PLL_CTL_PLL_LDIV |
> +		 PCIE_GLI_9767_SD_PLL_CTL_PLL_PDIV |
> +		 PCIE_GLI_9767_SD_PLL_CTL_PLL_DIR_EN);
> +	pll |= FIELD_PREP(PCIE_GLI_9767_SD_PLL_CTL_PLL_LDIV, ldiv) |
> +	       FIELD_PREP(PCIE_GLI_9767_SD_PLL_CTL_PLL_PDIV, pdiv) |
> +	       FIELD_PREP(PCIE_GLI_9767_SD_PLL_CTL_PLL_DIR_EN, dir);
> +	pci_write_config_dword(pdev, PCIE_GLI_9767_SD_PLL_CTL, pll);
> +
> +	gl9767_vhs_read(pdev);
> +
> +	/* wait for pll stable */
> +	mdelay(1);

So long as SDHCI_QUIRK_CLOCK_BEFORE_RESET is not used, it is OK
to sleep here, so msleep() or usleep_range()

> +}
> +
> +static void gl9767_set_ssc_pll_205mhz(struct pci_dev *pdev)
> +{
> +	bool enable = gl9767_ssc_enable(pdev);
> +
> +	/* set pll to 205MHz and ssc */
> +	gl9767_set_ssc(pdev, enable, 0x1F, 0xF5C3);
> +	gl9767_set_pll(pdev, 0x1, 0x246, 0x0);
> +}
> +
> +static void gl9767_disable_ssc_pll(struct pci_dev *pdev)
> +{
> +	u32 pll;
> +
> +	gl9767_vhs_write(pdev);
> +
> +	pci_read_config_dword(pdev, PCIE_GLI_9767_SD_PLL_CTL, &pll);
> +	pll &= ~(PCIE_GLI_9767_SD_PLL_CTL_PLL_DIR_EN | PCIE_GLI_9767_SD_PLL_CTL_SSC_EN);
> +	pci_write_config_dword(pdev, PCIE_GLI_9767_SD_PLL_CTL, pll);
> +
> +	gl9767_vhs_read(pdev);
> +}
> +
> +static void sdhci_gl9767_set_clock(struct sdhci_host *host, unsigned int clock)
> +{
> +	struct sdhci_pci_slot *slot = sdhci_priv(host);
> +	struct mmc_ios *ios = &host->mmc->ios;
> +	struct pci_dev *pdev;
> +	u32 value;
> +	u16 clk;
> +
> +	pdev = slot->chip->pdev;
> +	host->mmc->actual_clock = 0;
> +
> +	gl9767_vhs_write(pdev);
> +
> +	pci_read_config_dword(pdev, PCIE_GLI_9767_CFG, &value);
> +	value |= PCIE_GLI_9767_CFG_LOW_PWR_OFF;
> +	pci_write_config_dword(pdev, PCIE_GLI_9767_CFG, value);
> +
> +	gl9767_disable_ssc_pll(pdev);
> +	sdhci_writew(host, 0, SDHCI_CLOCK_CONTROL);
> +
> +	if (clock == 0)
> +		return;
> +
> +	clk = sdhci_calc_clk(host, clock, &host->mmc->actual_clock);
> +	if (clock == 200000000 && ios->timing == MMC_TIMING_UHS_SDR104) {
> +		host->mmc->actual_clock = 205000000;
> +		gl9767_set_ssc_pll_205mhz(pdev);
> +	}
> +
> +	sdhci_enable_clk(host, clk);
> +
> +	pci_read_config_dword(pdev, PCIE_GLI_9767_CFG, &value);
> +	value &= ~PCIE_GLI_9767_CFG_LOW_PWR_OFF;
> +	pci_write_config_dword(pdev, PCIE_GLI_9767_CFG, value);
> +
> +	gl9767_vhs_read(pdev);
> +}
> +
>  static void gli_set_9767(struct sdhci_host *host)
>  {
>  	u32 value;
> @@ -1293,7 +1426,7 @@ const struct sdhci_pci_fixes sdhci_gl9763e = {
>  };
>  
>  static const struct sdhci_ops sdhci_gl9767_ops = {
> -	.set_clock		 = sdhci_set_clock,
> +	.set_clock		 = sdhci_gl9767_set_clock,
>  	.enable_dma		 = sdhci_pci_enable_dma,
>  	.set_bus_width		 = sdhci_set_bus_width,
>  	.reset			 = sdhci_gl9767_reset,