atmel-mci: Platform code for supporting multiple mmc slots

Add the necessary platform infrastructure to support multiple mmc/sdcard
slots all at once through a single controller. Currently, the driver
will use the first valid slot it finds and stick with that, but later
patches will add support for switching between several slots on the fly.

Extend the platform data structure with per-slot information: MMC/SDcard
bus width and card detect/write protect pins. This will affect the pin
muxing as well as the capabilities announced to the mmc core.

Note that board code is now required to supply a mci_platform_data
struct to at32_add_device_mci().

Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>

2 files changed, 24 insertions, 6 deletions

diff --git a/drivers/mmc/host/atmel-mci-regs.h b/drivers/mmc/host/atmel-mci-regs.h
index 26bd80e..b58364e 100644
--- a/drivers/mmc/host/atmel-mci-regs.h
+++ b/drivers/mmc/host/atmel-mci-regs.h
@@ -25,8 +25,10 @@
 #define MCI_SDCR		0x000c	/* SD Card / SDIO */
 # define MCI_SDCSEL_SLOT_A	(  0 <<  0)	/* Select SD slot A */
 # define MCI_SDCSEL_SLOT_B	(  1 <<  0)	/* Select SD slot A */
-# define MCI_SDCBUS_1BIT	(  0 <<  7)	/* 1-bit data bus */
-# define MCI_SDCBUS_4BIT	(  1 <<  7)	/* 4-bit data bus */
+# define MCI_SDCSEL_MASK	(  3 <<  0)
+# define MCI_SDCBUS_1BIT	(  0 <<  6)	/* 1-bit data bus */
+# define MCI_SDCBUS_4BIT	(  2 <<  6)	/* 4-bit data bus */
+# define MCI_SDCBUS_MASK	(  3 <<  6)
 #define MCI_ARGR		0x0010	/* Command Argument */
 #define MCI_CMDR		0x0014	/* Command */
 # define MCI_CMDR_CMDNB(x)	((x) <<  0)	/* Command Opcode */
diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c
index 14ab28d..8170905 100644
--- a/drivers/mmc/host/atmel-mci.c
+++ b/drivers/mmc/host/atmel-mci.c
@@ -508,9 +508,10 @@ static void atmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 {
 	struct atmel_mci	*host = mmc_priv(mmc);
 
+	host->sdc_reg &= ~MCI_SDCBUS_MASK;
 	switch (ios->bus_width) {
 	case MMC_BUS_WIDTH_1:
-		host->sdc_reg = 0;
+		host->sdc_reg |= MCI_SDCBUS_1BIT;
 		break;
 	case MMC_BUS_WIDTH_4:
 		host->sdc_reg = MCI_SDCBUS_4BIT;
@@ -1014,9 +1015,11 @@ static irqreturn_t atmci_detect_interrupt(int irq, void *dev_id)
 static int __init atmci_probe(struct platform_device *pdev)
 {
 	struct mci_platform_data	*pdata;
+	struct mci_slot_pdata		*slot;
 	struct atmel_mci *host;
 	struct mmc_host *mmc;
 	struct resource *regs;
+	u32 sdc_reg;
 	int irq;
 	int ret;
 
@@ -1030,6 +1033,17 @@ static int __init atmci_probe(struct platform_device *pdev)
 	if (irq < 0)
 		return irq;
 
+	/* TODO: Allow using several slots at once */
+	if (pdata->slot[0].bus_width) {
+		sdc_reg = MCI_SDCSEL_SLOT_A;
+		slot = &pdata->slot[0];
+	} else if (pdata->slot[1].bus_width) {
+		sdc_reg = MCI_SDCSEL_SLOT_B;
+		slot = &pdata->slot[1];
+	} else {
+		return -EINVAL;
+	}
+
 	mmc = mmc_alloc_host(sizeof(struct atmel_mci), &pdev->dev);
 	if (!mmc)
 		return -ENOMEM;
@@ -1037,8 +1051,9 @@ static int __init atmci_probe(struct platform_device *pdev)
 	host = mmc_priv(mmc);
 	host->pdev = pdev;
 	host->mmc = mmc;
-	host->detect_pin = pdata->detect_pin;
-	host->wp_pin = pdata->wp_pin;
+	host->detect_pin = slot->detect_pin;
+	host->wp_pin = slot->wp_pin;
+	host->sdc_reg = sdc_reg;
 
 	host->mck = clk_get(&pdev->dev, "mci_clk");
 	if (IS_ERR(host->mck)) {
@@ -1062,7 +1077,8 @@ static int __init atmci_probe(struct platform_device *pdev)
 	mmc->f_min = (host->bus_hz + 511) / 512;
 	mmc->f_max = host->bus_hz / 2;
 	mmc->ocr_avail	= MMC_VDD_32_33 | MMC_VDD_33_34;
-	mmc->caps |= MMC_CAP_4_BIT_DATA;
+	if (slot->bus_width >= 4)
+		mmc->caps |= MMC_CAP_4_BIT_DATA;
 
 	mmc->max_hw_segs = 64;
 	mmc->max_phys_segs = 64;