mmc: rtsx: add 74 Clocks in power on flow

commit 1f311c94aabdb419c28e3147bcc8ab89269f1a7e upstream.

SD spec definition:
"Host provides at least 74 Clocks before issuing first command"
After 1ms for the voltage stable then start issuing the Clock signals

if POWER STATE is
MMC_POWER_OFF to MMC_POWER_UP to issue Clock signal to card
MMC_POWER_UP to MMC_POWER_ON to stop issuing signal to card

Signed-off-by: Ricky Wu <ricky_wu@realtek.com>
Link: https://lore.kernel.org/r/1badf10aba764191a1a752edcbf90389@realtek.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Ricky Wu <ricky_wu@realtek.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Christian Loehle <cloehle@hyperstone.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/mmc/host/rtsx_pci_sdmmc.c b/drivers/mmc/host/rtsx_pci_sdmmc.c
index 9de6a32f0c9fc8a590cddb2387a8544ca0a2e4a9..0b1d4f2b58624b2f6d54bdb51d01259f08464704 100644 (file)
--- a/drivers/mmc/host/rtsx_pci_sdmmc.c
+++ b/drivers/mmc/host/rtsx_pci_sdmmc.c
@@ -49,10 +49,7 @@ struct realtek_pci_sdmmc {
        bool                    double_clk;
        bool                    eject;
        bool                    initial_mode;
-       int                     power_state;
-#define SDMMC_POWER_ON         1
-#define SDMMC_POWER_OFF                0
-
+       int                     prev_power_state;
        int                     sg_count;
        s32                     cookie;
        int                     cookie_sg_count;
@@ -913,14 +910,21 @@ static int sd_set_bus_width(struct realtek_pci_sdmmc *host,
        return err;
 }
 
-static int sd_power_on(struct realtek_pci_sdmmc *host)
+static int sd_power_on(struct realtek_pci_sdmmc *host, unsigned char power_mode)
 {
        struct rtsx_pcr *pcr = host->pcr;
        int err;
 
-       if (host->power_state == SDMMC_POWER_ON)
+       if (host->prev_power_state == MMC_POWER_ON)
                return 0;
 
+       if (host->prev_power_state == MMC_POWER_UP) {
+               rtsx_pci_write_register(pcr, SD_BUS_STAT, SD_CLK_TOGGLE_EN, 0);
+               goto finish;
+       }
+
+       msleep(100);
+
        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,
@@ -939,11 +943,17 @@ static int sd_power_on(struct realtek_pci_sdmmc *host)
        if (err < 0)
                return err;
 
+       mdelay(1);
+
        err = rtsx_pci_write_register(pcr, CARD_OE, SD_OUTPUT_EN, SD_OUTPUT_EN);
        if (err < 0)
                return err;
 
-       host->power_state = SDMMC_POWER_ON;
+       /* send at least 74 clocks */
+       rtsx_pci_write_register(pcr, SD_BUS_STAT, SD_CLK_TOGGLE_EN, SD_CLK_TOGGLE_EN);
+
+finish:
+       host->prev_power_state = power_mode;
        return 0;
 }
 
@@ -952,7 +962,7 @@ static int sd_power_off(struct realtek_pci_sdmmc *host)
        struct rtsx_pcr *pcr = host->pcr;
        int err;
 
-       host->power_state = SDMMC_POWER_OFF;
+       host->prev_power_state = MMC_POWER_OFF;
 
        rtsx_pci_init_cmd(pcr);
 
@@ -978,7 +988,7 @@ static int sd_set_power_mode(struct realtek_pci_sdmmc *host,
        if (power_mode == MMC_POWER_OFF)
                err = sd_power_off(host);
        else
-               err = sd_power_on(host);
+               err = sd_power_on(host, power_mode);
 
        return err;
 }
@@ -1416,7 +1426,7 @@ static int rtsx_pci_sdmmc_drv_probe(struct platform_device *pdev)
        host->mmc = mmc;
        host->pdev = pdev;
        host->cookie = -1;
-       host->power_state = SDMMC_POWER_OFF;
+       host->prev_power_state = MMC_POWER_OFF;
        INIT_WORK(&host->work, sd_request);
        platform_set_drvdata(pdev, host);
        pcr->slots[RTSX_SD_CARD].p_dev = pdev;