mmc: host: sdhci-pci: Add Genesys Logic GL975x support

Add support for the GL9750 and GL9755 chipsets.

Enable v4 mode and wait 5ms after set 1.8V signal enable for GL9750/
GL9755. Fix the value of SDHCI_MAX_CURRENT register and use the vendor
tuning flow for GL9750.

Co-developed-by: Michael K Johnson <johnsonm@danlj.org>
Signed-off-by: Michael K Johnson <johnsonm@danlj.org>
Signed-off-by: Ben Chuang <ben.chuang@genesyslogic.com.tw>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
diff --git a/drivers/mmc/host/sdhci-pci-gli.c b/drivers/mmc/host/sdhci-pci-gli.c
new file mode 100644
index 0000000..5eea8d70
--- /dev/null
+++ b/drivers/mmc/host/sdhci-pci-gli.c
@@ -0,0 +1,352 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2019 Genesys Logic, Inc.
+ *
+ * Authors: Ben Chuang <ben.chuang@genesyslogic.com.tw>
+ *
+ * Version: v0.9.0 (2019-08-08)
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/pci.h>
+#include <linux/mmc/mmc.h>
+#include <linux/delay.h>
+#include "sdhci.h"
+#include "sdhci-pci.h"
+
+/*  Genesys Logic extra registers */
+#define SDHCI_GLI_9750_WT         0x800
+#define   SDHCI_GLI_9750_WT_EN      BIT(0)
+#define   GLI_9750_WT_EN_ON	    0x1
+#define   GLI_9750_WT_EN_OFF	    0x0
+
+#define SDHCI_GLI_9750_DRIVING      0x860
+#define   SDHCI_GLI_9750_DRIVING_1    GENMASK(11, 0)
+#define   SDHCI_GLI_9750_DRIVING_2    GENMASK(27, 26)
+#define   GLI_9750_DRIVING_1_VALUE    0xFFF
+#define   GLI_9750_DRIVING_2_VALUE    0x3
+
+#define SDHCI_GLI_9750_PLL	      0x864
+#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_SW_CTRL      0x874
+#define   SDHCI_GLI_9750_SW_CTRL_4    GENMASK(7, 6)
+#define   GLI_9750_SW_CTRL_4_VALUE    0x3
+
+#define SDHCI_GLI_9750_MISC            0x878
+#define   SDHCI_GLI_9750_MISC_TX1_INV    BIT(2)
+#define   SDHCI_GLI_9750_MISC_RX_INV     BIT(3)
+#define   SDHCI_GLI_9750_MISC_TX1_DLY    GENMASK(6, 4)
+#define   GLI_9750_MISC_TX1_INV_VALUE    0x0
+#define   GLI_9750_MISC_RX_INV_ON        0x1
+#define   GLI_9750_MISC_RX_INV_OFF       0x0
+#define   GLI_9750_MISC_RX_INV_VALUE     GLI_9750_MISC_RX_INV_OFF
+#define   GLI_9750_MISC_TX1_DLY_VALUE    0x5
+
+#define SDHCI_GLI_9750_TUNING_CONTROL	          0x540
+#define   SDHCI_GLI_9750_TUNING_CONTROL_EN          BIT(4)
+#define   GLI_9750_TUNING_CONTROL_EN_ON             0x1
+#define   GLI_9750_TUNING_CONTROL_EN_OFF            0x0
+#define   SDHCI_GLI_9750_TUNING_CONTROL_GLITCH_1    BIT(16)
+#define   SDHCI_GLI_9750_TUNING_CONTROL_GLITCH_2    GENMASK(20, 19)
+#define   GLI_9750_TUNING_CONTROL_GLITCH_1_VALUE    0x1
+#define   GLI_9750_TUNING_CONTROL_GLITCH_2_VALUE    0x2
+
+#define SDHCI_GLI_9750_TUNING_PARAMETERS           0x544
+#define   SDHCI_GLI_9750_TUNING_PARAMETERS_RX_DLY    GENMASK(2, 0)
+#define   GLI_9750_TUNING_PARAMETERS_RX_DLY_VALUE    0x1
+
+#define GLI_MAX_TUNING_LOOP 40
+
+/* Genesys Logic chipset */
+static inline void gl9750_wt_on(struct sdhci_host *host)
+{
+	u32 wt_value;
+	u32 wt_enable;
+
+	wt_value = sdhci_readl(host, SDHCI_GLI_9750_WT);
+	wt_enable = FIELD_GET(SDHCI_GLI_9750_WT_EN, wt_value);
+
+	if (wt_enable == GLI_9750_WT_EN_ON)
+		return;
+
+	wt_value &= ~SDHCI_GLI_9750_WT_EN;
+	wt_value |= FIELD_PREP(SDHCI_GLI_9750_WT_EN, GLI_9750_WT_EN_ON);
+
+	sdhci_writel(host, wt_value, SDHCI_GLI_9750_WT);
+}
+
+static inline void gl9750_wt_off(struct sdhci_host *host)
+{
+	u32 wt_value;
+	u32 wt_enable;
+
+	wt_value = sdhci_readl(host, SDHCI_GLI_9750_WT);
+	wt_enable = FIELD_GET(SDHCI_GLI_9750_WT_EN, wt_value);
+
+	if (wt_enable == GLI_9750_WT_EN_OFF)
+		return;
+
+	wt_value &= ~SDHCI_GLI_9750_WT_EN;
+	wt_value |= FIELD_PREP(SDHCI_GLI_9750_WT_EN, GLI_9750_WT_EN_OFF);
+
+	sdhci_writel(host, wt_value, SDHCI_GLI_9750_WT);
+}
+
+static void gli_set_9750(struct sdhci_host *host)
+{
+	u32 driving_value;
+	u32 pll_value;
+	u32 sw_ctrl_value;
+	u32 misc_value;
+	u32 parameter_value;
+	u32 control_value;
+	u16 ctrl2;
+
+	gl9750_wt_on(host);
+
+	driving_value = sdhci_readl(host, SDHCI_GLI_9750_DRIVING);
+	pll_value = sdhci_readl(host, SDHCI_GLI_9750_PLL);
+	sw_ctrl_value = sdhci_readl(host, SDHCI_GLI_9750_SW_CTRL);
+	misc_value = sdhci_readl(host, SDHCI_GLI_9750_MISC);
+	parameter_value = sdhci_readl(host, SDHCI_GLI_9750_TUNING_PARAMETERS);
+	control_value = sdhci_readl(host, SDHCI_GLI_9750_TUNING_CONTROL);
+
+	driving_value &= ~(SDHCI_GLI_9750_DRIVING_1);
+	driving_value &= ~(SDHCI_GLI_9750_DRIVING_2);
+	driving_value |= FIELD_PREP(SDHCI_GLI_9750_DRIVING_1,
+				    GLI_9750_DRIVING_1_VALUE);
+	driving_value |= FIELD_PREP(SDHCI_GLI_9750_DRIVING_2,
+				    GLI_9750_DRIVING_2_VALUE);
+	sdhci_writel(host, driving_value, SDHCI_GLI_9750_DRIVING);
+
+	sw_ctrl_value &= ~SDHCI_GLI_9750_SW_CTRL_4;
+	sw_ctrl_value |= FIELD_PREP(SDHCI_GLI_9750_SW_CTRL_4,
+				    GLI_9750_SW_CTRL_4_VALUE);
+	sdhci_writel(host, sw_ctrl_value, SDHCI_GLI_9750_SW_CTRL);
+
+	/* reset the tuning flow after reinit and before starting tuning */
+	pll_value &= ~SDHCI_GLI_9750_PLL_TX2_INV;
+	pll_value &= ~SDHCI_GLI_9750_PLL_TX2_DLY;
+	pll_value |= FIELD_PREP(SDHCI_GLI_9750_PLL_TX2_INV,
+				GLI_9750_PLL_TX2_INV_VALUE);
+	pll_value |= FIELD_PREP(SDHCI_GLI_9750_PLL_TX2_DLY,
+				GLI_9750_PLL_TX2_DLY_VALUE);
+
+	misc_value &= ~SDHCI_GLI_9750_MISC_TX1_INV;
+	misc_value &= ~SDHCI_GLI_9750_MISC_RX_INV;
+	misc_value &= ~SDHCI_GLI_9750_MISC_TX1_DLY;
+	misc_value |= FIELD_PREP(SDHCI_GLI_9750_MISC_TX1_INV,
+				 GLI_9750_MISC_TX1_INV_VALUE);
+	misc_value |= FIELD_PREP(SDHCI_GLI_9750_MISC_RX_INV,
+				 GLI_9750_MISC_RX_INV_VALUE);
+	misc_value |= FIELD_PREP(SDHCI_GLI_9750_MISC_TX1_DLY,
+				 GLI_9750_MISC_TX1_DLY_VALUE);
+
+	parameter_value &= ~SDHCI_GLI_9750_TUNING_PARAMETERS_RX_DLY;
+	parameter_value |= FIELD_PREP(SDHCI_GLI_9750_TUNING_PARAMETERS_RX_DLY,
+				      GLI_9750_TUNING_PARAMETERS_RX_DLY_VALUE);
+
+	control_value &= ~SDHCI_GLI_9750_TUNING_CONTROL_GLITCH_1;
+	control_value &= ~SDHCI_GLI_9750_TUNING_CONTROL_GLITCH_2;
+	control_value |= FIELD_PREP(SDHCI_GLI_9750_TUNING_CONTROL_GLITCH_1,
+				    GLI_9750_TUNING_CONTROL_GLITCH_1_VALUE);
+	control_value |= FIELD_PREP(SDHCI_GLI_9750_TUNING_CONTROL_GLITCH_2,
+				    GLI_9750_TUNING_CONTROL_GLITCH_2_VALUE);
+
+	sdhci_writel(host, pll_value, SDHCI_GLI_9750_PLL);
+	sdhci_writel(host, misc_value, SDHCI_GLI_9750_MISC);
+
+	/* disable tuned clk */
+	ctrl2 = sdhci_readw(host, SDHCI_HOST_CONTROL2);
+	ctrl2 &= ~SDHCI_CTRL_TUNED_CLK;
+	sdhci_writew(host, ctrl2, SDHCI_HOST_CONTROL2);
+
+	/* enable tuning parameters control */
+	control_value &= ~SDHCI_GLI_9750_TUNING_CONTROL_EN;
+	control_value |= FIELD_PREP(SDHCI_GLI_9750_TUNING_CONTROL_EN,
+				    GLI_9750_TUNING_CONTROL_EN_ON);
+	sdhci_writel(host, control_value, SDHCI_GLI_9750_TUNING_CONTROL);
+
+	/* write tuning parameters */
+	sdhci_writel(host, parameter_value, SDHCI_GLI_9750_TUNING_PARAMETERS);
+
+	/* disable tuning parameters control */
+	control_value &= ~SDHCI_GLI_9750_TUNING_CONTROL_EN;
+	control_value |= FIELD_PREP(SDHCI_GLI_9750_TUNING_CONTROL_EN,
+				    GLI_9750_TUNING_CONTROL_EN_OFF);
+	sdhci_writel(host, control_value, SDHCI_GLI_9750_TUNING_CONTROL);
+
+	/* clear tuned clk */
+	ctrl2 = sdhci_readw(host, SDHCI_HOST_CONTROL2);
+	ctrl2 &= ~SDHCI_CTRL_TUNED_CLK;
+	sdhci_writew(host, ctrl2, SDHCI_HOST_CONTROL2);
+
+	gl9750_wt_off(host);
+}
+
+static void gli_set_9750_rx_inv(struct sdhci_host *host, bool b)
+{
+	u32 misc_value;
+
+	gl9750_wt_on(host);
+
+	misc_value = sdhci_readl(host, SDHCI_GLI_9750_MISC);
+	misc_value &= ~SDHCI_GLI_9750_MISC_RX_INV;
+	if (b) {
+		misc_value |= FIELD_PREP(SDHCI_GLI_9750_MISC_RX_INV,
+					 GLI_9750_MISC_RX_INV_ON);
+	} else {
+		misc_value |= FIELD_PREP(SDHCI_GLI_9750_MISC_RX_INV,
+					 GLI_9750_MISC_RX_INV_OFF);
+	}
+	sdhci_writel(host, misc_value, SDHCI_GLI_9750_MISC);
+
+	gl9750_wt_off(host);
+}
+
+static int __sdhci_execute_tuning_9750(struct sdhci_host *host, u32 opcode)
+{
+	int i;
+	int rx_inv;
+
+	for (rx_inv = 0; rx_inv < 2; rx_inv++) {
+		gli_set_9750_rx_inv(host, !!rx_inv);
+		sdhci_start_tuning(host);
+
+		for (i = 0; i < GLI_MAX_TUNING_LOOP; i++) {
+			u16 ctrl;
+
+			sdhci_send_tuning(host, opcode);
+
+			if (!host->tuning_done) {
+				sdhci_abort_tuning(host, opcode);
+				break;
+			}
+
+			ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
+			if (!(ctrl & SDHCI_CTRL_EXEC_TUNING)) {
+				if (ctrl & SDHCI_CTRL_TUNED_CLK)
+					return 0; /* Success! */
+				break;
+			}
+		}
+	}
+	if (!host->tuning_done) {
+		pr_info("%s: Tuning timeout, falling back to fixed sampling clock\n",
+			mmc_hostname(host->mmc));
+		return -ETIMEDOUT;
+	}
+
+	pr_info("%s: Tuning failed, falling back to fixed sampling clock\n",
+		mmc_hostname(host->mmc));
+	sdhci_reset_tuning(host);
+
+	return -EAGAIN;
+}
+
+static int gl9750_execute_tuning(struct sdhci_host *host, u32 opcode)
+{
+	host->mmc->retune_period = 0;
+	if (host->tuning_mode == SDHCI_TUNING_MODE_1)
+		host->mmc->retune_period = host->tuning_count;
+
+	gli_set_9750(host);
+	host->tuning_err = __sdhci_execute_tuning_9750(host, opcode);
+	sdhci_end_tuning(host);
+
+	return 0;
+}
+
+static int gli_probe_slot_gl9750(struct sdhci_pci_slot *slot)
+{
+	struct sdhci_host *host = slot->host;
+
+	slot->host->mmc->caps2 |= MMC_CAP2_NO_SDIO;
+	sdhci_enable_v4_mode(host);
+
+	return 0;
+}
+
+static int gli_probe_slot_gl9755(struct sdhci_pci_slot *slot)
+{
+	struct sdhci_host *host = slot->host;
+
+	slot->host->mmc->caps2 |= MMC_CAP2_NO_SDIO;
+	sdhci_enable_v4_mode(host);
+
+	return 0;
+}
+
+static void sdhci_gli_voltage_switch(struct sdhci_host *host)
+{
+	/*
+	 * According to Section 3.6.1 signal voltage switch procedure in
+	 * SD Host Controller Simplified Spec. 4.20, steps 6~8 are as
+	 * follows:
+	 * (6) Set 1.8V Signal Enable in the Host Control 2 register.
+	 * (7) Wait 5ms. 1.8V voltage regulator shall be stable within this
+	 *     period.
+	 * (8) If 1.8V Signal Enable is cleared by Host Controller, go to
+	 *     step (12).
+	 *
+	 * Wait 5ms after set 1.8V signal enable in Host Control 2 register
+	 * to ensure 1.8V signal enable bit is set by GL9750/GL9755.
+	 */
+	usleep_range(5000, 5500);
+}
+
+static void sdhci_gl9750_reset(struct sdhci_host *host, u8 mask)
+{
+	sdhci_reset(host, mask);
+	gli_set_9750(host);
+}
+
+static u32 sdhci_gl9750_readl(struct sdhci_host *host, int reg)
+{
+	u32 value;
+
+	value = readl(host->ioaddr + reg);
+	if (unlikely(reg == SDHCI_MAX_CURRENT && !(value & 0xff)))
+		value |= 0xc8;
+
+	return value;
+}
+
+static const struct sdhci_ops sdhci_gl9755_ops = {
+	.set_clock		= sdhci_set_clock,
+	.enable_dma		= sdhci_pci_enable_dma,
+	.set_bus_width		= sdhci_set_bus_width,
+	.reset			= sdhci_reset,
+	.set_uhs_signaling	= sdhci_set_uhs_signaling,
+	.voltage_switch		= sdhci_gli_voltage_switch,
+};
+
+const struct sdhci_pci_fixes sdhci_gl9755 = {
+	.quirks		= SDHCI_QUIRK_NO_ENDATTR_IN_NOPDESC,
+	.quirks2	= SDHCI_QUIRK2_BROKEN_DDR50,
+	.probe_slot	= gli_probe_slot_gl9755,
+	.ops            = &sdhci_gl9755_ops,
+};
+
+static const struct sdhci_ops sdhci_gl9750_ops = {
+	.read_l                 = sdhci_gl9750_readl,
+	.set_clock		= sdhci_set_clock,
+	.enable_dma		= sdhci_pci_enable_dma,
+	.set_bus_width		= sdhci_set_bus_width,
+	.reset			= sdhci_gl9750_reset,
+	.set_uhs_signaling	= sdhci_set_uhs_signaling,
+	.voltage_switch		= sdhci_gli_voltage_switch,
+	.platform_execute_tuning = gl9750_execute_tuning,
+};
+
+const struct sdhci_pci_fixes sdhci_gl9750 = {
+	.quirks		= SDHCI_QUIRK_NO_ENDATTR_IN_NOPDESC,
+	.quirks2	= SDHCI_QUIRK2_BROKEN_DDR50,
+	.probe_slot	= gli_probe_slot_gl9750,
+	.ops            = &sdhci_gl9750_ops,
+};