mmc: sdhci-pci-gli: Set SDR104's clock to 205MHz and enable SSC for GL975x

Set SDR104's clock to 205MHz and enable SSC for GL9750 and GL9755

Signed-off-by: Ben Chuang <ben.chuang@genesyslogic.com.tw>
Link: https://lore.kernel.org/r/20200717033350.13006-1-benchuanggli@gmail.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/sdhci-pci-gli.c

@@ -31,10 +31,18 @@
 #define   SDHCI_GLI_9750_ALL_RST      (BIT(24)|BIT(25)|BIT(28)|BIT(30))
 
 #define SDHCI_GLI_9750_PLL	      0x864
+#define   SDHCI_GLI_9750_PLL_LDIV       GENMASK(9, 0)
+#define   SDHCI_GLI_9750_PLL_PDIV       GENMASK(14, 12)
+#define   SDHCI_GLI_9750_PLL_DIR        BIT(15)
 #define   SDHCI_GLI_9750_PLL_TX2_INV    BIT(23)
 #define   SDHCI_GLI_9750_PLL_TX2_DLY    GENMASK(22, 20)
 #define   GLI_9750_PLL_TX2_INV_VALUE    0x1
 #define   GLI_9750_PLL_TX2_DLY_VALUE    0x0
+#define   SDHCI_GLI_9750_PLLSSC_STEP    GENMASK(28, 24)
+#define   SDHCI_GLI_9750_PLLSSC_EN      BIT(31)
+
+#define SDHCI_GLI_9750_PLLSSC        0x86C
+#define   SDHCI_GLI_9750_PLLSSC_PPM    GENMASK(31, 16)
 
 #define SDHCI_GLI_9750_SW_CTRL      0x874
 #define   SDHCI_GLI_9750_SW_CTRL_4    GENMASK(7, 6)
@@ -76,6 +84,21 @@
 #define PCIE_GLI_9763E_SCR	 0x8E0
 #define   GLI_9763E_SCR_AXI_REQ	   BIT(9)
 
+#define PCI_GLI_9755_WT       0x800
+#define   PCI_GLI_9755_WT_EN    BIT(0)
+#define   GLI_9755_WT_EN_ON     0x1
+#define   GLI_9755_WT_EN_OFF    0x0
+
+#define PCI_GLI_9755_PLL            0x64
+#define   PCI_GLI_9755_PLL_LDIV       GENMASK(9, 0)
+#define   PCI_GLI_9755_PLL_PDIV       GENMASK(14, 12)
+#define   PCI_GLI_9755_PLL_DIR        BIT(15)
+#define   PCI_GLI_9755_PLLSSC_STEP    GENMASK(28, 24)
+#define   PCI_GLI_9755_PLLSSC_EN      BIT(31)
+
+#define PCI_GLI_9755_PLLSSC        0x68
+#define   PCI_GLI_9755_PLLSSC_PPM    GENMASK(15, 0)
+
 #define GLI_MAX_TUNING_LOOP 40
 
 /* Genesys Logic chipset */
@@ -280,6 +303,84 @@ static int gl9750_execute_tuning(struct sdhci_host *host, u32 opcode)
 	return 0;
 }
 
+static void gl9750_disable_ssc_pll(struct sdhci_host *host)
+{
+	u32 pll;
+
+	gl9750_wt_on(host);
+	pll = sdhci_readl(host, SDHCI_GLI_9750_PLL);
+	pll &= ~(SDHCI_GLI_9750_PLL_DIR | SDHCI_GLI_9750_PLLSSC_EN);
+	sdhci_writel(host, pll, SDHCI_GLI_9750_PLL);
+	gl9750_wt_off(host);
+}
+
+static void gl9750_set_pll(struct sdhci_host *host, u8 dir, u16 ldiv, u8 pdiv)
+{
+	u32 pll;
+
+	gl9750_wt_on(host);
+	pll = sdhci_readl(host, SDHCI_GLI_9750_PLL);
+	pll &= ~(SDHCI_GLI_9750_PLL_LDIV |
+		 SDHCI_GLI_9750_PLL_PDIV |
+		 SDHCI_GLI_9750_PLL_DIR);
+	pll |= FIELD_PREP(SDHCI_GLI_9750_PLL_LDIV, ldiv) |
+	       FIELD_PREP(SDHCI_GLI_9750_PLL_PDIV, pdiv) |
+	       FIELD_PREP(SDHCI_GLI_9750_PLL_DIR, dir);
+	sdhci_writel(host, pll, SDHCI_GLI_9750_PLL);
+	gl9750_wt_off(host);
+
+	/* wait for pll stable */
+	mdelay(1);
+}
+
+static void gl9750_set_ssc(struct sdhci_host *host, u8 enable, u8 step, u16 ppm)
+{
+	u32 pll;
+	u32 ssc;
+
+	gl9750_wt_on(host);
+	pll = sdhci_readl(host, SDHCI_GLI_9750_PLL);
+	ssc = sdhci_readl(host, SDHCI_GLI_9750_PLLSSC);
+	pll &= ~(SDHCI_GLI_9750_PLLSSC_STEP |
+		 SDHCI_GLI_9750_PLLSSC_EN);
+	ssc &= ~SDHCI_GLI_9750_PLLSSC_PPM;
+	pll |= FIELD_PREP(SDHCI_GLI_9750_PLLSSC_STEP, step) |
+	       FIELD_PREP(SDHCI_GLI_9750_PLLSSC_EN, enable);
+	ssc |= FIELD_PREP(SDHCI_GLI_9750_PLLSSC_PPM, ppm);
+	sdhci_writel(host, ssc, SDHCI_GLI_9750_PLLSSC);
+	sdhci_writel(host, pll, SDHCI_GLI_9750_PLL);
+	gl9750_wt_off(host);
+}
+
+static void gl9750_set_ssc_pll_205mhz(struct sdhci_host *host)
+{
+	/* set pll to 205MHz and enable ssc */
+	gl9750_set_ssc(host, 0x1, 0x1F, 0xFFE7);
+	gl9750_set_pll(host, 0x1, 0x246, 0x0);
+}
+
+static void sdhci_gl9750_set_clock(struct sdhci_host *host, unsigned int clock)
+{
+	struct mmc_ios *ios = &host->mmc->ios;
+	u16 clk;
+
+	host->mmc->actual_clock = 0;
+
+	gl9750_disable_ssc_pll(host);
+	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;
+		gl9750_set_ssc_pll_205mhz(host);
+	}
+
+	sdhci_enable_clk(host, clk);
+}
+
 static void gli_pcie_enable_msi(struct sdhci_pci_slot *slot)
 {
 	int ret;
@@ -295,6 +396,121 @@ static void gli_pcie_enable_msi(struct sdhci_pci_slot *slot)
 	slot->host->irq = pci_irq_vector(slot->chip->pdev, 0);
 }
 
+static inline void gl9755_wt_on(struct pci_dev *pdev)
+{
+	u32 wt_value;
+	u32 wt_enable;
+
+	pci_read_config_dword(pdev, PCI_GLI_9755_WT, &wt_value);
+	wt_enable = FIELD_GET(PCI_GLI_9755_WT_EN, wt_value);
+
+	if (wt_enable == GLI_9755_WT_EN_ON)
+		return;
+
+	wt_value &= ~PCI_GLI_9755_WT_EN;
+	wt_value |= FIELD_PREP(PCI_GLI_9755_WT_EN, GLI_9755_WT_EN_ON);
+
+	pci_write_config_dword(pdev, PCI_GLI_9755_WT, wt_value);
+}
+
+static inline void gl9755_wt_off(struct pci_dev *pdev)
+{
+	u32 wt_value;
+	u32 wt_enable;
+
+	pci_read_config_dword(pdev, PCI_GLI_9755_WT, &wt_value);
+	wt_enable = FIELD_GET(PCI_GLI_9755_WT_EN, wt_value);
+
+	if (wt_enable == GLI_9755_WT_EN_OFF)
+		return;
+
+	wt_value &= ~PCI_GLI_9755_WT_EN;
+	wt_value |= FIELD_PREP(PCI_GLI_9755_WT_EN, GLI_9755_WT_EN_OFF);
+
+	pci_write_config_dword(pdev, PCI_GLI_9755_WT, wt_value);
+}
+
+static void gl9755_disable_ssc_pll(struct pci_dev *pdev)
+{
+	u32 pll;
+
+	gl9755_wt_on(pdev);
+	pci_read_config_dword(pdev, PCI_GLI_9755_PLL, &pll);
+	pll &= ~(PCI_GLI_9755_PLL_DIR | PCI_GLI_9755_PLLSSC_EN);
+	pci_write_config_dword(pdev, PCI_GLI_9755_PLL, pll);
+	gl9755_wt_off(pdev);
+}
+
+static void gl9755_set_pll(struct pci_dev *pdev, u8 dir, u16 ldiv, u8 pdiv)
+{
+	u32 pll;
+
+	gl9755_wt_on(pdev);
+	pci_read_config_dword(pdev, PCI_GLI_9755_PLL, &pll);
+	pll &= ~(PCI_GLI_9755_PLL_LDIV |
+		 PCI_GLI_9755_PLL_PDIV |
+		 PCI_GLI_9755_PLL_DIR);
+	pll |= FIELD_PREP(PCI_GLI_9755_PLL_LDIV, ldiv) |
+	       FIELD_PREP(PCI_GLI_9755_PLL_PDIV, pdiv) |
+	       FIELD_PREP(PCI_GLI_9755_PLL_DIR, dir);
+	pci_write_config_dword(pdev, PCI_GLI_9755_PLL, pll);
+	gl9755_wt_off(pdev);
+
+	/* wait for pll stable */
+	mdelay(1);
+}
+
+static void gl9755_set_ssc(struct pci_dev *pdev, u8 enable, u8 step, u16 ppm)
+{
+	u32 pll;
+	u32 ssc;
+
+	gl9755_wt_on(pdev);
+	pci_read_config_dword(pdev, PCI_GLI_9755_PLL, &pll);
+	pci_read_config_dword(pdev, PCI_GLI_9755_PLLSSC, &ssc);
+	pll &= ~(PCI_GLI_9755_PLLSSC_STEP |
+		 PCI_GLI_9755_PLLSSC_EN);
+	ssc &= ~PCI_GLI_9755_PLLSSC_PPM;
+	pll |= FIELD_PREP(PCI_GLI_9755_PLLSSC_STEP, step) |
+	       FIELD_PREP(PCI_GLI_9755_PLLSSC_EN, enable);
+	ssc |= FIELD_PREP(PCI_GLI_9755_PLLSSC_PPM, ppm);
+	pci_write_config_dword(pdev, PCI_GLI_9755_PLLSSC, ssc);
+	pci_write_config_dword(pdev, PCI_GLI_9755_PLL, pll);
+	gl9755_wt_off(pdev);
+}
+
+static void gl9755_set_ssc_pll_205mhz(struct pci_dev *pdev)
+{
+	/* set pll to 205MHz and enable ssc */
+	gl9755_set_ssc(pdev, 0x1, 0x1F, 0xFFE7);
+	gl9755_set_pll(pdev, 0x1, 0x246, 0x0);
+}
+
+static void sdhci_gl9755_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;
+	u16 clk;
+
+	pdev = slot->chip->pdev;
+	host->mmc->actual_clock = 0;
+
+	gl9755_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;
+		gl9755_set_ssc_pll_205mhz(pdev);
+	}
+
+	sdhci_enable_clk(host, clk);
+}
+
 static int gli_probe_slot_gl9750(struct sdhci_pci_slot *slot)
 {
 	struct sdhci_host *host = slot->host;
@@ -440,7 +656,7 @@ static int gli_probe_slot_gl9763e(struct sdhci_pci_slot *slot)
 }
 
 static const struct sdhci_ops sdhci_gl9755_ops = {
-	.set_clock		= sdhci_set_clock,
+	.set_clock		= sdhci_gl9755_set_clock,
 	.enable_dma		= sdhci_pci_enable_dma,
 	.set_bus_width		= sdhci_set_bus_width,
 	.reset			= sdhci_reset,
@@ -460,7 +676,7 @@ const struct sdhci_pci_fixes sdhci_gl9755 = {
 
 static const struct sdhci_ops sdhci_gl9750_ops = {
 	.read_l                 = sdhci_gl9750_readl,
-	.set_clock		= sdhci_set_clock,
+	.set_clock		= sdhci_gl9750_set_clock,
 	.enable_dma		= sdhci_pci_enable_dma,
 	.set_bus_width		= sdhci_set_bus_width,
 	.reset			= sdhci_gl9750_reset,