mmc: sdhci: update signal voltage switch code

The protocol related code is moved to core stack. So update the host
driver accordingly.
Signed-off-by: Kevin Liu <kliu5@marvell.com>
Tested-by: Tim Wang <wangtt@marvell.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

drivers/mmc/host/sdhci.c

@@ -1615,11 +1615,23 @@ static void sdhci_enable_sdio_irq(struct mmc_host *mmc, int enable)
 	spin_unlock_irqrestore(&host->lock, flags);
 }
 
-static int sdhci_do_3_3v_signal_voltage_switch(struct sdhci_host *host,
-						u16 ctrl)
+static int sdhci_do_start_signal_voltage_switch(struct sdhci_host *host,
+						int signal_voltage)
 {
+	u16 ctrl;
 	int ret;
 
+	/*
+	 * Signal Voltage Switching is only applicable for Host Controllers
+	 * v3.00 and above.
+	 */
+	if (host->version < SDHCI_SPEC_300)
+		return 0;
+
+	ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
+
+	switch (signal_voltage) {
+	case MMC_SIGNAL_VOLTAGE_330:
 		/* Set 1.8V Signal Enable in the Host Control2 register to 0 */
 		ctrl &= ~SDHCI_CTRL_VDD_180;
 		sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2);
@@ -1643,117 +1655,55 @@ static int sdhci_do_3_3v_signal_voltage_switch(struct sdhci_host *host,
 		pr_warning("%s: 3.3V regulator output did not became stable\n",
 				mmc_hostname(host->mmc));
 
+		return -EAGAIN;
+	case MMC_SIGNAL_VOLTAGE_180:
+		if (host->vqmmc) {
+			ret = regulator_set_voltage(host->vqmmc,
+					1700000, 1950000);
+			if (ret) {
+				pr_warning("%s: Switching to 1.8V signalling voltage "
+						" failed\n", mmc_hostname(host->mmc));
 				return -EIO;
-}
-
-static int sdhci_do_1_8v_signal_voltage_switch(struct sdhci_host *host,
-						u16 ctrl)
-{
-	u8 pwr;
-	u16 clk;
-	u32 present_state;
-	int ret;
-
-	/* Stop SDCLK */
-	clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
-	clk &= ~SDHCI_CLOCK_CARD_EN;
-	sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
+			}
+		}
 
-	/* Check whether DAT[3:0] is 0000 */
-	present_state = sdhci_readl(host, SDHCI_PRESENT_STATE);
-	if (!((present_state & SDHCI_DATA_LVL_MASK) >>
-	       SDHCI_DATA_LVL_SHIFT)) {
 		/*
 		 * Enable 1.8V Signal Enable in the Host Control2
 		 * register
 		 */
-		if (host->vqmmc)
-			ret = regulator_set_voltage(host->vqmmc,
-				1700000, 1950000);
-		else
-			ret = 0;
-
-		if (!ret) {
 		ctrl |= SDHCI_CTRL_VDD_180;
 		sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2);
 
 		/* Wait for 5ms */
 		usleep_range(5000, 5500);
 
+		/* 1.8V regulator output should be stable within 5 ms */
 		ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
-			if (ctrl & SDHCI_CTRL_VDD_180) {
-				/* Provide SDCLK again and wait for 1ms */
-				clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
-				clk |= SDHCI_CLOCK_CARD_EN;
-				sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
-				usleep_range(1000, 1500);
-
-				/*
-				 * If DAT[3:0] level is 1111b, then the card
-				 * was successfully switched to 1.8V signaling.
-				 */
-				present_state = sdhci_readl(host,
-							SDHCI_PRESENT_STATE);
-				if ((present_state & SDHCI_DATA_LVL_MASK) ==
-				     SDHCI_DATA_LVL_MASK)
+		if (ctrl & SDHCI_CTRL_VDD_180)
 			return 0;
-			}
-		}
-	}
 
-	/*
-	 * If we are here, that means the switch to 1.8V signaling
-	 * failed. We power cycle the card, and retry initialization
-	 * sequence by setting S18R to 0.
-	 */
-	pwr = sdhci_readb(host, SDHCI_POWER_CONTROL);
-	pwr &= ~SDHCI_POWER_ON;
-	sdhci_writeb(host, pwr, SDHCI_POWER_CONTROL);
-	if (host->vmmc)
-		regulator_disable(host->vmmc);
-
-	/* Wait for 1ms as per the spec */
-	usleep_range(1000, 1500);
-	pwr |= SDHCI_POWER_ON;
-	sdhci_writeb(host, pwr, SDHCI_POWER_CONTROL);
-	if (host->vmmc)
-		regulator_enable(host->vmmc);
-
-	pr_warning("%s: Switching to 1.8V signalling voltage failed, "
-		   "retrying with S18R set to 0\n", mmc_hostname(host->mmc));
+		pr_warning("%s: 1.8V regulator output did not became stable\n",
+				mmc_hostname(host->mmc));
 
 		return -EAGAIN;
-}
-
-static int sdhci_do_start_signal_voltage_switch(struct sdhci_host *host,
-						struct mmc_ios *ios)
-{
-	u16 ctrl;
-
-	/*
-	 * Signal Voltage Switching is only applicable for Host Controllers
-	 * v3.00 and above.
-	 */
-	if (host->version < SDHCI_SPEC_300)
+	case MMC_SIGNAL_VOLTAGE_120:
+		if (host->vqmmc) {
+			ret = regulator_set_voltage(host->vqmmc, 1100000, 1300000);
+			if (ret) {
+				pr_warning("%s: Switching to 1.2V signalling voltage "
+						" failed\n", mmc_hostname(host->mmc));
+				return -EIO;
+			}
+		}
 		return 0;
-
-	/*
-	 * We first check whether the request is to set signalling voltage
-	 * to 3.3V. If so, we change the voltage to 3.3V and return quickly.
-	 */
-	ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
-	if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_330)
-		return sdhci_do_3_3v_signal_voltage_switch(host, ctrl);
-	else if (!(ctrl & SDHCI_CTRL_VDD_180) &&
-			(ios->signal_voltage == MMC_SIGNAL_VOLTAGE_180))
-		return sdhci_do_1_8v_signal_voltage_switch(host, ctrl);
-	else
+	default:
 		/* No signal voltage switch required */
 		return 0;
+	}
 }
 
 static int sdhci_start_signal_voltage_switch(struct mmc_host *mmc,
-	struct mmc_ios *ios)
+	int signal_voltage)
 {
 	struct sdhci_host *host = mmc_priv(mmc);
 	int err;
@@ -1761,11 +1711,24 @@ static int sdhci_start_signal_voltage_switch(struct mmc_host *mmc,
 	if (host->version < SDHCI_SPEC_300)
 		return 0;
 	sdhci_runtime_pm_get(host);
-	err = sdhci_do_start_signal_voltage_switch(host, ios);
+	err = sdhci_do_start_signal_voltage_switch(host, signal_voltage);
 	sdhci_runtime_pm_put(host);
 	return err;
 }
 
+static int sdhci_card_busy(struct mmc_host *mmc)
+{
+	struct sdhci_host *host = mmc_priv(mmc);
+	u32 present_state;
+
+	sdhci_runtime_pm_get(host);
+	/* Check whether DAT[3:0] is 0000 */
+	present_state = sdhci_readl(host, SDHCI_PRESENT_STATE);
+	sdhci_runtime_pm_put(host);
+
+	return !(present_state & SDHCI_DATA_LVL_MASK);
+}
+
 static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
 {
 	struct sdhci_host *host;
@@ -2036,6 +1999,7 @@ static const struct mmc_host_ops sdhci_ops = {
 	.execute_tuning			= sdhci_execute_tuning,
 	.enable_preset_value		= sdhci_enable_preset_value,
 	.card_event			= sdhci_card_event,
+	.card_busy	= sdhci_card_busy,
 };
 
 /*****************************************************************************\