Commit 94b94a93 authored by Ludovic Barre's avatar Ludovic Barre Committed by Ulf Hansson
Browse files

mmc: mmci_sdmmc: Implement signal voltage callbacks 



To prepare the voltage switch procedure, the VSWITCHEN bit must be set
before sending the CMD11. To confirm completion of voltage switch, the
VSWEND flag must be checked.

Signed-off-by: default avatarLudovic Barre <ludovic.barre@st.com>
Link: https://lore.kernel.org/r/20200128090636.13689-9-ludovic.barre@st.com


Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
parent 75773165

drivers/mmc/host/mmci.h

+4 −0
Original line number Diff line number Diff line
@@ -165,6 +165,7 @@ 
/* Extended status bits for the STM32 variants */

#define MCI_STM32_BUSYD0	BIT(20)

#define MCI_STM32_BUSYD0END	BIT(21)

#define MCI_STM32_VSWEND	BIT(25)



#define MMCICLEAR		0x038

#define MCI_CMDCRCFAILCLR	(1 << 0)
@@ -182,6 +183,9 @@ 
#define MCI_ST_SDIOITC		(1 << 22)

#define MCI_ST_CEATAENDC	(1 << 23)

#define MCI_ST_BUSYENDC		(1 << 24)

/* Extended clear bits for the STM32 variants */

#define MCI_STM32_VSWENDC	BIT(25)

#define MCI_STM32_CKSTOPC	BIT(26)



#define MMCIMASK0		0x03c

#define MCI_CMDCRCFAILMASK	(1 << 0)

drivers/mmc/host/mmci_stm32_sdmmc.c

+43 −0
Original line number Diff line number Diff line
@@ -32,6 +32,7 @@ 
#define DLYB_CFGR_UNIT_MAX	127



#define DLYB_LNG_TIMEOUT_US	1000

#define SDMMC_VSWEND_TIMEOUT_US 10000



struct sdmmc_lli_desc {

	u32 idmalar;
@@ -265,6 +266,7 @@ static void mmci_sdmmc_set_pwrreg(struct mmci_host *host, unsigned int pwr) 
	struct mmc_ios ios = host->mmc->ios;

	struct sdmmc_dlyb *dlyb = host->variant_priv;



	/* adds OF options */

	pwr = host->pwr_reg_add;



	sdmmc_dlyb_input_ck(dlyb);
@@ -291,6 +293,10 @@ static void mmci_sdmmc_set_pwrreg(struct mmci_host *host, unsigned int pwr) 
		writel(MCI_IRQENABLE | host->variant->start_err,

		       host->base + MMCIMASK0);



		/* preserves voltage switch bits */

		pwr |= host->pwr_reg & (MCI_STM32_VSWITCHEN |

					MCI_STM32_VSWITCH);



		/*

		 * After a power-cycle state, we must set the SDMMC in

		 * Power-off. The SDMMC_D[7:0], SDMMC_CMD and SDMMC_CK are
@@ -456,6 +462,41 @@ static int sdmmc_execute_tuning(struct mmc_host *mmc, u32 opcode) 
	return sdmmc_dlyb_phase_tuning(host, opcode);

}



static void sdmmc_pre_sig_volt_vswitch(struct mmci_host *host)

{

	/* clear the voltage switch completion flag */

	writel_relaxed(MCI_STM32_VSWENDC, host->base + MMCICLEAR);

	/* enable Voltage switch procedure */

	mmci_write_pwrreg(host, host->pwr_reg | MCI_STM32_VSWITCHEN);

}



static int sdmmc_post_sig_volt_switch(struct mmci_host *host,

				      struct mmc_ios *ios)

{

	unsigned long flags;

	u32 status;

	int ret = 0;



	if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_180) {

		spin_lock_irqsave(&host->lock, flags);

		mmci_write_pwrreg(host, host->pwr_reg | MCI_STM32_VSWITCH);

		spin_unlock_irqrestore(&host->lock, flags);



		/* wait voltage switch completion while 10ms */

		ret = readl_relaxed_poll_timeout(host->base + MMCISTATUS,

						 status,

						 (status & MCI_STM32_VSWEND),

						 10, SDMMC_VSWEND_TIMEOUT_US);



		writel_relaxed(MCI_STM32_VSWENDC | MCI_STM32_CKSTOPC,

			       host->base + MMCICLEAR);

		mmci_write_pwrreg(host, host->pwr_reg &

				  ~(MCI_STM32_VSWITCHEN | MCI_STM32_VSWITCH));

	}



	return ret;

}



static struct mmci_host_ops sdmmc_variant_ops = {

	.validate_data = sdmmc_idma_validate_data,

	.prep_data = sdmmc_idma_prep_data,
@@ -467,6 +508,8 @@ static struct mmci_host_ops sdmmc_variant_ops = { 
	.set_clkreg = mmci_sdmmc_set_clkreg,

	.set_pwrreg = mmci_sdmmc_set_pwrreg,

	.busy_complete = sdmmc_busy_complete,

	.pre_sig_volt_switch = sdmmc_pre_sig_volt_vswitch,

	.post_sig_volt_switch = sdmmc_post_sig_volt_switch,

};



void sdmmc_variant_init(struct mmci_host *host)