mmc: enable/disable functions for SDIO

Like many other buses, the devices (functions) on the SDIO bus
must be enabled before they can be used. Add functions that allow
drivers to do so.
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>

drivers/mmc/core/sdio_io.c

@@ -11,6 +11,7 @@
 
 #include <linux/mmc/host.h>
 #include <linux/mmc/card.h>
+#include <linux/mmc/sdio.h>
 #include <linux/mmc/sdio_func.h>
 
 #include "sdio_ops.h"
@@ -47,6 +48,98 @@ void sdio_release_host(struct sdio_func *func)
 }
 EXPORT_SYMBOL_GPL(sdio_release_host);
 
+/**
+ *	sdio_enable_func - enables a SDIO function for usage
+ *	@func: SDIO function to enable
+ *
+ *	Powers up and activates a SDIO function so that register
+ *	access is possible.
+ */
+int sdio_enable_func(struct sdio_func *func)
+{
+	int ret;
+	unsigned char reg;
+	unsigned long timeout;
+
+	BUG_ON(!func);
+	BUG_ON(!func->card);
+
+	pr_debug("SDIO: Enabling device %s...\n", sdio_func_id(func));
+
+	ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IOEx, 0, &reg);
+	if (ret)
+		goto err;
+
+	reg |= 1 << func->num;
+
+	ret = mmc_io_rw_direct(func->card, 1, 0, SDIO_CCCR_IOEx, reg, NULL);
+	if (ret)
+		goto err;
+
+	/*
+	 * FIXME: This should timeout based on information in the CIS,
+	 * but we don't have card to parse that yet.
+	 */
+	timeout = jiffies + HZ;
+
+	while (1) {
+		ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IORx, 0, &reg);
+		if (ret)
+			goto err;
+		if (reg & (1 << func->num))
+			break;
+		ret = -ETIME;
+		if (time_after(jiffies, timeout))
+			goto err;
+	}
+
+	pr_debug("SDIO: Enabled device %s\n", sdio_func_id(func));
+
+	return 0;
+
+err:
+	pr_debug("SDIO: Failed to enable device %s\n", sdio_func_id(func));
+	return ret;
+}
+EXPORT_SYMBOL_GPL(sdio_enable_func);
+
+/**
+ *	sdio_disable_func - disable a SDIO function
+ *	@func: SDIO function to disable
+ *
+ *	Powers down and deactivates a SDIO function. Register access
+ *	to this function will fail until the function is reenabled.
+ */
+int sdio_disable_func(struct sdio_func *func)
+{
+	int ret;
+	unsigned char reg;
+
+	BUG_ON(!func);
+	BUG_ON(!func->card);
+
+	pr_debug("SDIO: Disabling device %s...\n", sdio_func_id(func));
+
+	ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IOEx, 0, &reg);
+	if (ret)
+		goto err;
+
+	reg &= ~(1 << func->num);
+
+	ret = mmc_io_rw_direct(func->card, 1, 0, SDIO_CCCR_IOEx, reg, NULL);
+	if (ret)
+		goto err;
+
+	pr_debug("SDIO: Disabled device %s\n", sdio_func_id(func));
+
+	return 0;
+
+err:
+	pr_debug("SDIO: Failed to disable device %s\n", sdio_func_id(func));
+	return -EIO;
+}
+EXPORT_SYMBOL_GPL(sdio_disable_func);
+
 /**
  *	sdio_readb - read a single byte from a SDIO function
  *	@func: SDIO function to access

include/linux/mmc/sdio.h

@@ -49,5 +49,97 @@
 #define R5_STATUS(x)		(x & 0xCB00)
 #define R5_IO_CURRENT_STATE(x)	((x & 0x3000) >> 12) /* s, b */
 
+/*
+ * Card Common Control Registers (CCCR)
+ */
+
+#define SDIO_CCCR_CCCR		0x00
+
+#define  SDIO_CCCR_REV_1_00	0	/* CCCR/FBR Version 1.00 */
+#define  SDIO_CCCR_REV_1_10	1	/* CCCR/FBR Version 1.10 */
+#define  SDIO_CCCR_REV_1_20	2	/* CCCR/FBR Version 1.20 */
+
+#define  SDIO_SDIO_REV_1_00	0	/* SDIO Spec Version 1.00 */
+#define  SDIO_SDIO_REV_1_10	1	/* SDIO Spec Version 1.10 */
+#define  SDIO_SDIO_REV_1_20	2	/* SDIO Spec Version 1.20 */
+#define  SDIO_SDIO_REV_2_00	3	/* SDIO Spec Version 2.00 */
+
+#define SDIO_CCCR_SD		0x01
+
+#define  SDIO_SD_REV_1_01	0	/* SD Physical Spec Version 1.01 */
+#define  SDIO_SD_REV_1_10	1	/* SD Physical Spec Version 1.10 */
+#define  SDIO_SD_REV_2_00	2	/* SD Physical Spec Version 2.00 */
+
+#define SDIO_CCCR_IOEx		0x02
+#define SDIO_CCCR_IORx		0x03
+
+#define SDIO_CCCR_IENx		0x04	/* Function/Master Interrupt Enable */
+#define SDIO_CCCR_INTx		0x05	/* Function Interrupt Pending */
+
+#define SDIO_CCCR_ABORT		0x06	/* function abort/card reset */
+
+#define SDIO_CCCR_IF		0x07	/* bus interface controls */
+
+#define  SDIO_BUS_WIDTH_1BIT	0x00
+#define  SDIO_BUS_WIDTH_4BIT	0x02
+
+#define  SDIO_BUS_CD_DISABLE     0x80	/* disable pull-up on DAT3 (pin 1) */
+
+#define SDIO_CCCR_CAPS		0x08
+
+#define  SDIO_CCCR_CAP_SDC	0x01	/* can do CMD52 while data transfer */
+#define  SDIO_CCCR_CAP_SMB	0x02	/* can do multi-block xfers (CMD53) */
+#define  SDIO_CCCR_CAP_SRW	0x04	/* supports read-wait protocol */
+#define  SDIO_CCCR_CAP_SBS	0x08	/* supports suspend/resume */
+#define  SDIO_CCCR_CAP_S4MI	0x10	/* interrupt during 4-bit CMD53 */
+#define  SDIO_CCCR_CAP_E4MI	0x20	/* enable ints during 4-bit CMD53 */
+#define  SDIO_CCCR_CAP_LSC	0x40	/* low speed card */
+#define  SDIO_CCCR_CAP_4BLS	0x80	/* 4 bit low speed card */
+
+#define SDIO_CCCR_CIS		0x09	/* common CIS pointer (3 bytes) */
+
+/* Following 4 regs are valid only if SBS is set */
+#define SDIO_CCCR_SUSPEND	0x0c
+#define SDIO_CCCR_SELx		0x0d
+#define SDIO_CCCR_EXECx		0x0e
+#define SDIO_CCCR_READYx	0x0f
+
+#define SDIO_CCCR_BLKSIZE	0x10
+
+#define SDIO_CCCR_POWER		0x12
+
+#define  SDIO_POWER_SMPC	0x01	/* Supports Master Power Control */
+#define  SDIO_POWER_EMPC	0x02	/* Enable Master Power Control */
+
+#define SDIO_CCCR_SPEED		0x13
+
+#define  SDIO_SPEED_SHS		0x01	/* Supports High-Speed mode */
+#define  SDIO_SPEED_EHS		0x02	/* Enable High-Speed mode */
+
+/*
+ * Function Basic Registers (FBR)
+ */
+
+#define SDIO_FBR_STD_IF		0x00
+
+#define  SDIO_FBR_SUPPORTS_CSA	0x40	/* supports Code Storage Area */
+#define  SDIO_FBR_ENABLE_CSA	0x80	/* enable Code Storage Area */
+
+#define SDIO_FBR_STD_IF_EXT	0x01
+
+#define SDIO_FBR_POWER		0x02
+
+#define  SDIO_FBR_POWER_SPS	0x01	/* Supports Power Selection */
+#define  SDIO_FBR_POWER_EPS	0x02	/* Enable (low) Power Selection */
+
+#define SDIO_FBR_CIS		0x09	/* CIS pointer (3 bytes) */
+
+
+#define SDIO_FBR_CSA		0x0C	/* CSA pointer (3 bytes) */
+
+#define SDIO_FBR_CSA_DATA	0x0F
+
+#define SDIO_FBR_BLKSIZE	0x10	/* block size (2 bytes) */
+
 #endif
 

include/linux/mmc/sdio_func.h

@@ -55,6 +55,9 @@ extern void sdio_unregister_driver(struct sdio_driver *);
 extern void sdio_claim_host(struct sdio_func *func);
 extern void sdio_release_host(struct sdio_func *func);
 
+extern int sdio_enable_func(struct sdio_func *func);
+extern int sdio_disable_func(struct sdio_func *func);
+
 extern unsigned char sdio_readb(struct sdio_func *func,
 	unsigned int addr, int *err_ret);