[PATCH] mmc: sdhci-pci-gli: Set SDR104's clock to 205MHz and enable SSC for GL975x - Linux-stable-mirror

13 Oct 2020

From: Ben Chuang ben.chuang@genesyslogic.com.tw
commit 786d33c887e15061ff95942db68fe5c6ca98e5fc upstream.
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
Cc: stable@vger.kernel.org # 5.4.x
---
Hi Greg and Sasha,
The patch is to improve the EMI of the hardware.
So it should be also required for some hardware devices using the v5.4.
Please tell me if have other questions.
Best regards,
Ben
drivers/mmc/host/sdhci-pci-gli.c | 220 ++++++++++++++++++++++++++++++-
 1 file changed, 218 insertions(+), 2 deletions(-)

diff --git a/drivers/mmc/host/sdhci-pci-gli.c b/drivers/mmc/host/sdhci-pci-gli.c
index fd76aa672e02..29d982eb44fc 100644
--- a/drivers/mmc/host/sdhci-pci-gli.c
+++ b/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)
@@ -63,6 +71,21 @@
 #define   SDHCI_GLI_9750_TUNING_PARAMETERS_RX_DLY    GENMASK(2, 0)
 #define   GLI_9750_TUNING_PARAMETERS_RX_DLY_VALUE    0x1
+#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 */
@@ -267,6 +290,84 @@ 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;
@@ -282,6 +383,121 @@ 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;
@@ -352,7 +568,7 @@ static int sdhci_pci_gli_resume(struct sdhci_pci_chip *chip)
 #endif
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,
@@ -372,7 +588,7 @@ 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,
-- 
2.28.0


    