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From:   Victor Shih <victorshihgli@gmail.com>
To:     ulf.hansson@linaro.org, adrian.hunter@intel.com
Cc:     linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org,
        benchuanggli@gmail.com, HL.Liu@genesyslogic.com.tw,
        Greg.tu@genesyslogic.com.tw, Victor Shih <victorshihgli@gmail.com>,
        Ben Chuang <ben.chuang@genesyslogic.com.tw>,
        Victor Shih <victor.shih@genesyslogic.com.tw>
Subject: [PATCH V4 2/4] mmc: sdhci-pci-gli: Set SDR104's clock to 205MHz and enable SSC for GL9767
Date:   Wed, 31 May 2023 19:15:16 +0800
Message-Id: <20230531111518.396868-3-victorshihgli@gmail.com>
In-Reply-To: <20230531111518.396868-1-victorshihgli@gmail.com>
References: <20230531111518.396868-1-victorshihgli@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

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>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
---
 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..392a106cea18 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 */
+	msleep(1);
+}
+
+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,
-- 
2.25.1