diff --git a/drivers/mmc/host/sdhci-of-arasan.c b/drivers/mmc/host/sdhci-of-arasan.c index e0f193f7e3e5..0b3a9cfed2df 100644 --- a/drivers/mmc/host/sdhci-of-arasan.c +++ b/drivers/mmc/host/sdhci-of-arasan.c @@ -35,6 +35,8 @@ #define CLK_CTRL_TIMEOUT_MASK (0xf << CLK_CTRL_TIMEOUT_SHIFT) #define CLK_CTRL_TIMEOUT_MIN_EXP 13 +#define PHY_CLK_TOO_SLOW_HZ 400000 + /* * On some SoCs the syscon area has a feature where the upper 16-bits of * each 32-bit register act as a write mask for the lower 16-bits. This allows @@ -77,6 +79,7 @@ struct sdhci_arasan_soc_ctl_map { * @host: Pointer to the main SDHCI host structure. * @clk_ahb: Pointer to the AHB clock * @phy: Pointer to the generic phy + * @is_phy_on: True if the PHY is on; false if not. * @sdcardclk_hw: Struct for the clock we might provide to a PHY. * @sdcardclk: Pointer to normal 'struct clock' for sdcardclk_hw. * @soc_ctl_base: Pointer to regmap for syscon for soc_ctl registers. @@ -86,6 +89,7 @@ struct sdhci_arasan_data { struct sdhci_host *host; struct clk *clk_ahb; struct phy *phy; + bool is_phy_on; struct clk_hw sdcardclk_hw; struct clk *sdcardclk; @@ -170,13 +174,47 @@ static void sdhci_arasan_set_clock(struct sdhci_host *host, unsigned int clock) struct sdhci_arasan_data *sdhci_arasan = sdhci_pltfm_priv(pltfm_host); bool ctrl_phy = false; - if (clock > MMC_HIGH_52_MAX_DTR && (!IS_ERR(sdhci_arasan->phy))) - ctrl_phy = true; + if (!IS_ERR(sdhci_arasan->phy)) { + if (!sdhci_arasan->is_phy_on && clock <= PHY_CLK_TOO_SLOW_HZ) { + /* + * If PHY off, set clock to max speed and power PHY on. + * + * Although PHY docs apparently suggest power cycling + * when changing the clock the PHY doesn't like to be + * powered on while at low speeds like those used in ID + * mode. Even worse is powering the PHY on while the + * clock is off. + * + * To workaround the PHY limitations, the best we can + * do is to power it on at a faster speed and then slam + * through low speeds without power cycling. + */ + sdhci_set_clock(host, host->max_clk); + spin_unlock_irq(&host->lock); + phy_power_on(sdhci_arasan->phy); + spin_lock_irq(&host->lock); + sdhci_arasan->is_phy_on = true; - if (ctrl_phy) { + /* + * We'll now fall through to the below case with + * ctrl_phy = false (so we won't turn off/on). The + * sdhci_set_clock() will set the real clock. + */ + } else if (clock > PHY_CLK_TOO_SLOW_HZ) { + /* + * At higher clock speeds the PHY is fine being power + * cycled and docs say you _should_ power cycle when + * changing clock speeds. + */ + ctrl_phy = true; + } + } + + if (ctrl_phy && sdhci_arasan->is_phy_on) { spin_unlock_irq(&host->lock); phy_power_off(sdhci_arasan->phy); spin_lock_irq(&host->lock); + sdhci_arasan->is_phy_on = false; } sdhci_set_clock(host, clock); @@ -185,6 +223,7 @@ static void sdhci_arasan_set_clock(struct sdhci_host *host, unsigned int clock) spin_unlock_irq(&host->lock); phy_power_on(sdhci_arasan->phy); spin_lock_irq(&host->lock); + sdhci_arasan->is_phy_on = true; } } @@ -239,13 +278,14 @@ static int sdhci_arasan_suspend(struct device *dev) if (ret) return ret; - if (!IS_ERR(sdhci_arasan->phy)) { + if (!IS_ERR(sdhci_arasan->phy) && sdhci_arasan->is_phy_on) { ret = phy_power_off(sdhci_arasan->phy); if (ret) { dev_err(dev, "Cannot power off phy.\n"); sdhci_resume_host(host); return ret; } + sdhci_arasan->is_phy_on = false; } clk_disable(pltfm_host->clk); @@ -281,12 +321,13 @@ static int sdhci_arasan_resume(struct device *dev) return ret; } - if (!IS_ERR(sdhci_arasan->phy)) { + if (!IS_ERR(sdhci_arasan->phy) && host->mmc->actual_clock) { ret = phy_power_on(sdhci_arasan->phy); if (ret) { dev_err(dev, "Cannot power on phy.\n"); return ret; } + sdhci_arasan->is_phy_on = true; } return sdhci_resume_host(host); @@ -547,12 +588,6 @@ static int sdhci_arasan_probe(struct platform_device *pdev) goto unreg_clk; } - ret = phy_power_on(sdhci_arasan->phy); - if (ret < 0) { - dev_err(&pdev->dev, "phy_power_on err.\n"); - goto err_phy_power; - } - host->mmc_host_ops.hs400_enhanced_strobe = sdhci_arasan_hs400_enhanced_strobe; } @@ -564,9 +599,6 @@ static int sdhci_arasan_probe(struct platform_device *pdev) return 0; err_add_host: - if (!IS_ERR(sdhci_arasan->phy)) - phy_power_off(sdhci_arasan->phy); -err_phy_power: if (!IS_ERR(sdhci_arasan->phy)) phy_exit(sdhci_arasan->phy); unreg_clk: @@ -589,7 +621,8 @@ static int sdhci_arasan_remove(struct platform_device *pdev) struct clk *clk_ahb = sdhci_arasan->clk_ahb; if (!IS_ERR(sdhci_arasan->phy)) { - phy_power_off(sdhci_arasan->phy); + if (sdhci_arasan->is_phy_on) + phy_power_off(sdhci_arasan->phy); phy_exit(sdhci_arasan->phy); }