[PATCH 3/3] mmc: brcmstb: save and restore registers during PM

[Kamal Dasu <kamal.dasu@broadcom.com>]

Added support to save and restore registers that are critical
during PM.

Signed-off-by: Kamal Dasu <kamal.dasu@broadcom.com>
---
 drivers/mmc/host/sdhci-brcmstb.c | 124 +++++++++++++++++++++++++++++--
 1 file changed, 119 insertions(+), 5 deletions(-)

diff --git a/drivers/mmc/host/sdhci-brcmstb.c b/drivers/mmc/host/sdhci-brcmstb.c
index 0905b316a24b..ffa602a99ab7 100644
--- a/drivers/mmc/host/sdhci-brcmstb.c
+++ b/drivers/mmc/host/sdhci-brcmstb.c
@@ -24,7 +24,9 @@
 #define BRCMSTB_MATCH_FLAGS_NO_64BIT		BIT(0)
 #define BRCMSTB_MATCH_FLAGS_BROKEN_TIMEOUT	BIT(1)
 #define BRCMSTB_MATCH_FLAGS_HAS_CLOCK_GATE	BIT(2)
-#define BRCMSTB_MATCH_FLAGS_USE_CARD_BUSY	BIT(4)
+#define BRCMSTB_MATCH_FLAGS_HAS_CFG_V1		BIT(3)
+#define BRCMSTB_MATCH_FLAGS_HAS_CFG_V2		BIT(4)
+#define BRCMSTB_MATCH_FLAGS_USE_CARD_BUSY	BIT(5)
 
 #define BRCMSTB_PRIV_FLAGS_HAS_CQE		BIT(0)
 #define BRCMSTB_PRIV_FLAGS_GATE_CLOCK		BIT(1)
@@ -38,19 +40,39 @@
 #define SDIO_CFG_OP_DLY_DEFAULT			0x80000003
 #define SDIO_CFG_CQ_CAPABILITY			0x4c
 #define SDIO_CFG_CQ_CAPABILITY_FMUL		GENMASK(13, 12)
+#define SDIO_CFG_SD_PIN_SEL			0x44
+#define SDIO_CFG_V1_SD_PIN_SEL			0x54
+#define SDIO_CFG_PHY_SW_MODE_0_RX_CTRL		0x7C
 #define SDIO_CFG_MAX_50MHZ_MODE			0x1ac
 #define SDIO_CFG_MAX_50MHZ_MODE_STRAP_OVERRIDE	BIT(31)
 #define SDIO_CFG_MAX_50MHZ_MODE_ENABLE		BIT(0)
 
+#define SDIO_BOOT_MAIN_CTL			0x0
+
 #define MMC_CAP_HSE_MASK	(MMC_CAP2_HSX00_1_2V | MMC_CAP2_HSX00_1_8V)
 /* Select all SD UHS type I SDR speed above 50MB/s */
 #define MMC_CAP_UHS_I_SDR_MASK	(MMC_CAP_UHS_SDR50 | MMC_CAP_UHS_SDR104)
 
+enum cfg_core_ver {
+	SDIO_CFG_CORE_V1 = 1,
+	SDIO_CFG_CORE_V2,
+};
+
+struct sdhci_brcmstb_saved_regs {
+	u32 sd_pin_sel;
+	u32 phy_sw_mode0_rxctrl;
+	u32 max_50mhz_mode;
+	u32 boot_main_ctl;
+};
+
 struct sdhci_brcmstb_priv {
 	void __iomem *cfg_regs;
+	void __iomem *boot_regs;
+	struct sdhci_brcmstb_saved_regs saved_regs;
 	unsigned int flags;
 	struct clk *base_clk;
 	u32 base_freq_hz;
+	void (*save_restore_regs)(struct mmc_host *mmc, int save);
 };
 
 struct brcmstb_match_priv {
@@ -60,6 +82,69 @@ struct brcmstb_match_priv {
 	const unsigned int flags;
 };
 
+static void sdhci_brcmstb_save_regs(struct mmc_host *mmc, enum cfg_core_ver ver)
+{
+	struct sdhci_host *host = mmc_priv(mmc);
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+	struct sdhci_brcmstb_priv *priv = sdhci_pltfm_priv(pltfm_host);
+	struct sdhci_brcmstb_saved_regs *sr = &priv->saved_regs;
+	void __iomem *cr = priv->cfg_regs;
+	bool is_emmc = mmc->caps & MMC_CAP_NONREMOVABLE;
+
+	/* save  */
+	if (is_emmc && priv->boot_regs)
+		sr->boot_main_ctl = readl(priv->boot_regs + SDIO_BOOT_MAIN_CTL);
+
+	if (ver == SDIO_CFG_CORE_V1) {
+		sr->sd_pin_sel = readl(cr + SDIO_CFG_V1_SD_PIN_SEL);
+		return;
+	}
+
+	sr->sd_pin_sel = readl(cr + SDIO_CFG_SD_PIN_SEL);
+	sr->phy_sw_mode0_rxctrl = readl(cr + SDIO_CFG_PHY_SW_MODE_0_RX_CTRL);
+	sr->max_50mhz_mode = readl(cr + SDIO_CFG_MAX_50MHZ_MODE);
+}
+
+static void sdhci_brcmstb_restore_regs(struct mmc_host *mmc,
+						enum cfg_core_ver ver)
+{
+	struct sdhci_host *host = mmc_priv(mmc);
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+	struct sdhci_brcmstb_priv *priv = sdhci_pltfm_priv(pltfm_host);
+	struct sdhci_brcmstb_saved_regs *sr = &priv->saved_regs;
+	void __iomem *cr = priv->cfg_regs;
+	bool is_emmc = mmc->caps & MMC_CAP_NONREMOVABLE;
+
+	/* restore */
+	if (is_emmc && priv->boot_regs)
+		writel(sr->boot_main_ctl, priv->boot_regs + SDIO_BOOT_MAIN_CTL);
+
+	if (ver == SDIO_CFG_CORE_V1) {
+		writel(sr->sd_pin_sel, cr + SDIO_CFG_SD_PIN_SEL);
+		return;
+	}
+
+	writel(sr->sd_pin_sel, cr + SDIO_CFG_SD_PIN_SEL);
+	writel(sr->phy_sw_mode0_rxctrl, cr + SDIO_CFG_PHY_SW_MODE_0_RX_CTRL);
+	writel(sr->max_50mhz_mode, cr + SDIO_CFG_MAX_50MHZ_MODE);
+}
+
+static void sdhci_brcmstb_save_restore_regs_v1(struct mmc_host *mmc, int save)
+{
+	if (save)
+		sdhci_brcmstb_save_regs(mmc, SDIO_CFG_CORE_V1);
+	else
+		sdhci_brcmstb_restore_regs(mmc, SDIO_CFG_CORE_V1);
+}
+
+static void sdhci_brcmstb_save_restore_regs_v2(struct mmc_host *mmc, int save)
+{
+	if (save)
+		sdhci_brcmstb_save_regs(mmc, SDIO_CFG_CORE_V2);
+	else
+		sdhci_brcmstb_restore_regs(mmc, SDIO_CFG_CORE_V2);
+}
+
 static inline void enable_clock_gating(struct sdhci_host *host)
 {
 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
@@ -300,24 +385,33 @@ static struct brcmstb_match_priv match_priv_7425 = {
 	.ops = &sdhci_brcmstb_ops,
 };
 
-static struct brcmstb_match_priv match_priv_7445 = {
+static struct brcmstb_match_priv match_priv_74371 = {
 	.flags = BRCMSTB_MATCH_FLAGS_BROKEN_TIMEOUT,
 	.ops = &sdhci_brcmstb_ops,
 };
 
+static struct brcmstb_match_priv match_priv_7445 = {
+	.flags = BRCMSTB_MATCH_FLAGS_BROKEN_TIMEOUT |
+			BRCMSTB_MATCH_FLAGS_HAS_CFG_V1,
+	.ops = &sdhci_brcmstb_ops,
+};
+
 static struct brcmstb_match_priv match_priv_72116 = {
-	.flags = BRCMSTB_MATCH_FLAGS_BROKEN_TIMEOUT,
+	.flags = BRCMSTB_MATCH_FLAGS_BROKEN_TIMEOUT |
+			BRCMSTB_MATCH_FLAGS_HAS_CFG_V1,
 	.ops = &sdhci_brcmstb_ops_72116,
 };
 
 static const struct brcmstb_match_priv match_priv_7216 = {
-	.flags = BRCMSTB_MATCH_FLAGS_HAS_CLOCK_GATE,
+	.flags = BRCMSTB_MATCH_FLAGS_HAS_CLOCK_GATE |
+			BRCMSTB_MATCH_FLAGS_HAS_CFG_V2,
 	.hs400es = sdhci_brcmstb_hs400es,
 	.ops = &sdhci_brcmstb_ops_7216,
 };
 
 static struct brcmstb_match_priv match_priv_74165b0 = {
-	.flags = BRCMSTB_MATCH_FLAGS_HAS_CLOCK_GATE,
+	.flags = BRCMSTB_MATCH_FLAGS_HAS_CLOCK_GATE |
+			BRCMSTB_MATCH_FLAGS_HAS_CFG_V2,
 	.hs400es = sdhci_brcmstb_hs400es,
 	.ops = &sdhci_brcmstb_ops_74165b0,
 };
@@ -325,6 +419,7 @@ static struct brcmstb_match_priv match_priv_74165b0 = {
 static const struct of_device_id __maybe_unused sdhci_brcm_of_match[] = {
 	{ .compatible = "brcm,bcm2712-sdhci", .data = &match_priv_2712 },
 	{ .compatible = "brcm,bcm7425-sdhci", .data = &match_priv_7425 },
+	{ .compatible = "brcm,bcm74371-sdhci", .data = &match_priv_74371 },
 	{ .compatible = "brcm,bcm7445-sdhci", .data = &match_priv_7445 },
 	{ .compatible = "brcm,bcm72116-sdhci", .data = &match_priv_72116 },
 	{ .compatible = "brcm,bcm7216-sdhci", .data = &match_priv_7216 },
@@ -441,6 +536,19 @@ static int sdhci_brcmstb_probe(struct platform_device *pdev)
 	if (res)
 		goto err;
 
+	/* map non-standard BOOT registers if present */
+	if (host->mmc->caps & MMC_CAP_NONREMOVABLE) {
+		priv->boot_regs = devm_platform_get_and_ioremap_resource(pdev, 2, NULL);
+		if (IS_ERR(priv->boot_regs))
+			priv->boot_regs = NULL;
+	}
+
+	if (match_priv->flags & BRCMSTB_MATCH_FLAGS_HAS_CFG_V1)
+		priv->save_restore_regs = sdhci_brcmstb_save_restore_regs_v1;
+
+	if (match_priv->flags & BRCMSTB_MATCH_FLAGS_HAS_CFG_V2)
+		priv->save_restore_regs = sdhci_brcmstb_save_restore_regs_v2;
+
 	/*
 	 * Automatic clock gating does not work for SD cards that may
 	 * voltage switch so only enable it for non-removable devices.
@@ -533,6 +641,9 @@ static int sdhci_brcmstb_suspend(struct device *dev)
 	struct sdhci_brcmstb_priv *priv = sdhci_pltfm_priv(pltfm_host);
 	int ret;
 
+	if (priv->save_restore_regs)
+		priv->save_restore_regs(host->mmc, 1);
+
 	clk_disable_unprepare(priv->base_clk);
 	if (host->mmc->caps2 & MMC_CAP2_CQE) {
 		ret = cqhci_suspend(host->mmc);
@@ -564,6 +675,9 @@ static int sdhci_brcmstb_resume(struct device *dev)
 			ret = clk_set_rate(priv->base_clk, priv->base_freq_hz);
 	}
 
+	if (priv->save_restore_regs)
+		priv->save_restore_regs(host->mmc, 0);
+
 	if (host->mmc->caps2 & MMC_CAP2_CQE)
 		ret = cqhci_resume(host->mmc);
 
-- 
2.34.1