mmc: rtsx_pci_sdmmc: Don't execute power up sequence repeatedly

For some Realtek card readers, the power up sequence can only be executed
when power has been turned off fully.

So the rtsx host should not start power up sequence again when set_ios
been called if the power has been turned on.
Signed-off-by: Wei WANG <wei_wang@realsil.com.cn>
Signed-off-by: Chris Ball <cjb@laptop.org>

drivers/mmc/host/rtsx_pci_sdmmc.c

@@ -57,6 +57,9 @@ struct realtek_pci_sdmmc {
 	bool			eject;
 	bool			initial_mode;
 	bool			ddr_mode;
+	int			power_state;
+#define SDMMC_POWER_ON		1
+#define SDMMC_POWER_OFF		0
 };
 
 static inline struct device *sdmmc_dev(struct realtek_pci_sdmmc *host)
@@ -765,6 +768,9 @@ static int sd_power_on(struct realtek_pci_sdmmc *host)
 	struct rtsx_pcr *pcr = host->pcr;
 	int err;
 
+	if (host->power_state == SDMMC_POWER_ON)
+		return 0;
+
 	rtsx_pci_init_cmd(pcr);
 	rtsx_pci_add_cmd(pcr, WRITE_REG_CMD, CARD_SELECT, 0x07, SD_MOD_SEL);
 	rtsx_pci_add_cmd(pcr, WRITE_REG_CMD, CARD_SHARE_MODE,
@@ -787,6 +793,7 @@ static int sd_power_on(struct realtek_pci_sdmmc *host)
 	if (err < 0)
 		return err;
 
+	host->power_state = SDMMC_POWER_ON;
 	return 0;
 }
 
@@ -795,6 +802,8 @@ static int sd_power_off(struct realtek_pci_sdmmc *host)
 	struct rtsx_pcr *pcr = host->pcr;
 	int err;
 
+	host->power_state = SDMMC_POWER_OFF;
+
 	rtsx_pci_init_cmd(pcr);
 
 	rtsx_pci_add_cmd(pcr, WRITE_REG_CMD, CARD_CLK_EN, SD_CLK_EN, 0);
@@ -1260,6 +1269,7 @@ static int rtsx_pci_sdmmc_drv_probe(struct platform_device *pdev)
 	host->pcr = pcr;
 	host->mmc = mmc;
 	host->pdev = pdev;
+	host->power_state = SDMMC_POWER_OFF;
 	platform_set_drvdata(pdev, host);
 	pcr->slots[RTSX_SD_CARD].p_dev = pdev;
 	pcr->slots[RTSX_SD_CARD].card_event = rtsx_pci_sdmmc_card_event;