diff mbox

mmc: Resubmit: Bus Width testing for eMMC and MMC Cards

Message ID A8541278-E69B-43AC-A820-B8D11F718FC1@marvell.com (mailing list archive)
State New, archived
Headers show

Commit Message

Philip Rakity Nov. 27, 2010, 7 p.m. UTC
None
diff mbox

Patch

diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 77f93c3..d20237b 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -531,12 +531,57 @@  static int mmc_init_card(struct mmc_host *host, u32 ocr,
 
 	/*
 	 * Activate wide bus and DDR (if supported).
+	 * Determine mmc bus width supported by probing card (if supported)
 	 */
 	if ((card->csd.mmca_vsn >= CSD_SPEC_VER_4) &&
 	    (host->caps & (MMC_CAP_4_BIT_DATA | MMC_CAP_8_BIT_DATA))) {
 		unsigned ext_csd_bit, bus_width;
+		int temp_caps = host->caps & (MMC_CAP_8_BIT_DATA | MMC_CAP_4_BIT_DATA);
 
-		if (host->caps & MMC_CAP_8_BIT_DATA) {
+		do {
+			if (temp_caps & MMC_CAP_8_BIT_DATA) {
+				ext_csd_bit = EXT_CSD_BUS_WIDTH_8;
+				bus_width = MMC_BUS_WIDTH_8;
+			} else {
+				ext_csd_bit = EXT_CSD_BUS_WIDTH_4;
+				bus_width = MMC_BUS_WIDTH_4;
+			}
+
+			err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
+					 EXT_CSD_BUS_WIDTH, ext_csd_bit);
+			if (err) {
+				printk(KERN_WARNING "%s: switch to bus width %d ddr %d "
+					   "failed\n", mmc_hostname(card->host),
+					   1 << bus_width, ddr);
+				err = 0;
+			} else {
+				mmc_set_bus_width_ddr(card->host, bus_width, MMC_SDR_MODE);
+				/*
+				 * if controller can't handle bus width test
+				 * try to use the highest bus width to
+				 * maintain compatibility with previous linux
+				 */
+				if ((host->caps & MMC_CAP_BUS_WIDTH_WORKS) == 0)
+					break;
+				if (mmc_test_bus_width (card, 1<<bus_width))
+					break;
+			}
+
+			if (bus_width == MMC_BUS_WIDTH_8)
+				temp_caps &= ~MMC_CAP_8_BIT_DATA;
+			else
+				temp_caps &= ~MMC_CAP_4_BIT_DATA;
+
+			if (temp_caps == 0) {
+				ext_csd_bit = EXT_CSD_BUS_WIDTH_1;
+				bus_width = MMC_BUS_WIDTH_1;
+			}
+		} while (temp_caps);
+
+		if (temp_caps == 0) {
+			ext_csd_bit = EXT_CSD_BUS_WIDTH_1;
+			bus_width = MMC_BUS_WIDTH_1;
+		} else if (temp_caps & MMC_CAP_8_BIT_DATA) {
 			if (ddr)
 				ext_csd_bit = EXT_CSD_DDR_BUS_WIDTH_8;
 			else
diff --git a/drivers/mmc/core/mmc_ops.c b/drivers/mmc/core/mmc_ops.c
index 326447c..2b115a3 100644
--- a/drivers/mmc/core/mmc_ops.c
+++ b/drivers/mmc/core/mmc_ops.c
@@ -20,6 +20,138 @@ 
 #include "core.h"
 #include "mmc_ops.h"
 
+int mmc_test_bus_width(struct mmc_card *card, int bits)
+{
+	struct mmc_request mrq;
+	struct mmc_command cmd;
+	struct mmc_data data;
+	struct scatterlist sg;
+	int len;
+	u8 test_data_write[8];
+	u8 test_data_read[64];
+
+	switch (bits) {
+	case 8:
+		test_data_write[0] = 0x55;
+		test_data_write[1] = 0xaa;
+		test_data_write[2] = 0x00;
+		test_data_write[3] = 0x00;
+		test_data_write[4] = 0x00;
+		test_data_write[5] = 0x00;
+		test_data_write[6] = 0x00;
+		test_data_write[7] = 0x00;
+		len = 8;
+		break;
+	case 4:
+		test_data_write[0] = 0x5a;
+		test_data_write[1] = 0x00;
+		test_data_write[2] = 0x00;
+		test_data_write[3] = 0x00;
+		len = 4;
+		break;
+	default:
+		/* 1 bit bus cards ALWAYS work */
+		return 1;
+	}
+
+	memset(&mrq, 0, sizeof(struct mmc_request));
+	memset(&cmd, 0, sizeof(struct mmc_command));
+	memset(&data, 0, sizeof(struct mmc_data));
+
+	cmd.opcode = MMC_BUSTEST_W;
+	cmd.arg = 0;
+
+	/* NOTE HACK:  the MMC_RSP_SPI_R1 is always correct here, but we
+	 * rely on callers to never use this with "native" calls for reading
+	 * CSD or CID.  Native versions of those commands use the R2 type,
+	 * not R1 plus a data block.
+	 */
+	cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_ADTC;
+
+	data.flags = MMC_DATA_WRITE;
+	data.blksz = len;
+	data.blocks = 1;
+	data.sg = &sg;
+	data.sg_len = 1;
+
+	mrq.cmd = &cmd;
+	mrq.data = &data;
+
+	sg_init_one(&sg, &test_data_write, len);
+
+	/*
+	 * The spec states that MMC_BUSTEST_W and BUSTEST_R accesses
+	 * have a maximum timeout of 64 clock cycles.
+	 */
+	data.timeout_ns = 0;
+	data.timeout_clks = 64;
+
+	mmc_wait_for_req(card->host, &mrq);
+
+	if (cmd.error || data.error ) {
+		printk(KERN_INFO "%s: Failed to send (BUSTEST_W) CMD19: %d %d\n",
+			mmc_hostname(card->host), cmd.error, data.error);
+	}
+
+	/* Now read back */
+	memset(&mrq, 0, sizeof(struct mmc_request));
+	memset(&cmd, 0, sizeof(struct mmc_command));
+	memset(&data, 0, sizeof(struct mmc_data));
+	memset (&test_data_read, 0, sizeof(test_data_read));
+
+	cmd.opcode = MMC_BUSTEST_R;
+	cmd.arg = 0;
+
+	/* NOTE HACK:  the MMC_RSP_SPI_R1 is always correct here, but we
+	 * rely on callers to never use this with "native" calls for reading
+	 * CSD or CID.  Native versions of those commands use the R2 type,
+	 * not R1 plus a data block.
+	 */
+	cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_ADTC;
+
+	data.flags = MMC_DATA_READ;
+	data.blksz = len;
+	data.blocks = 1;
+	data.sg = &sg;
+	data.sg_len = 1;
+
+	mrq.cmd = &cmd;
+	mrq.data = &data;
+
+	sg_init_one(&sg, &test_data_read, len);
+
+	data.timeout_ns = 0;
+	data.timeout_clks = 64;
+
+	mmc_wait_for_req(card->host, &mrq);
+
+	if (cmd.error) {
+		printk(KERN_INFO "%s: Failed to send CMD14: %d %d\n",
+			mmc_hostname(card->host), cmd.error, data.error);
+		return 0;
+	}
+
+#if 0
+#warning PRINT RESULTS FROM CMD14
+	printk (KERN_INFO "%s: Bits = %d, Got %02X %02X %02X %02X\n", __FUNCTION__,
+		bits,
+		test_data_read[0],
+		test_data_read[1],
+		test_data_read[2],
+		test_data_read[3]);
+#endif
+
+	switch (bits) {
+	case 8:
+		return (test_data_read[0] == 0xaa && test_data_read[1] == 0x55);
+	case 4:
+		return (test_data_read[0] == 0xa5);
+	case 1:
+		return (test_data_read[0] == 0x80);
+	}
+	return 0;
+}
+
 static int _mmc_select_card(struct mmc_host *host, struct mmc_card *card)
 {
 	int err;
diff --git a/drivers/mmc/core/mmc_ops.h b/drivers/mmc/core/mmc_ops.h
index 653eb8e..c08b9ad 100644
--- a/drivers/mmc/core/mmc_ops.h
+++ b/drivers/mmc/core/mmc_ops.h
@@ -26,6 +26,7 @@  int mmc_send_cid(struct mmc_host *host, u32 *cid);
 int mmc_spi_read_ocr(struct mmc_host *host, int highcap, u32 *ocrp);
 int mmc_spi_set_crc(struct mmc_host *host, int use_crc);
 int mmc_card_sleepawake(struct mmc_host *host, int sleep);
+int mmc_test_bus_width(struct mmc_card *card, int bits);
 
 #endif
 
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index 53496bb..1e3d9d2 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -169,6 +169,7 @@  struct mmc_host {
 #define MMC_CAP_1_2V_DDR	(1 << 12)	/* can support */
 						/* DDR mode at 1.2V */
 
+#define MMC_CAP_BUS_WIDTH_WORKS	(1 << 13)	/* CMD14/CMD19 bus width ok */
 	mmc_pm_flag_t		pm_caps;	/* supported pm features */
 
 #ifdef CONFIG_MMC_CLKGATE
diff --git a/include/linux/mmc/mmc.h b/include/linux/mmc/mmc.h
index 956fbd8..8e0d047 100644
--- a/include/linux/mmc/mmc.h
+++ b/include/linux/mmc/mmc.h
@@ -40,7 +40,9 @@ 
 #define MMC_READ_DAT_UNTIL_STOP  11   /* adtc [31:0] dadr        R1  */
 #define MMC_STOP_TRANSMISSION    12   /* ac                      R1b */
 #define MMC_SEND_STATUS          13   /* ac   [31:16] RCA        R1  */
+#define MMC_BUSTEST_R            14   /* adtc                    R1  */
 #define MMC_GO_INACTIVE_STATE    15   /* ac   [31:16] RCA            */
+#define MMC_BUSTEST_W            19   /* adtc                    R1  */
 #define MMC_SPI_READ_OCR         58   /* spi                  spi_R3 */
 #define MMC_SPI_CRC_ON_OFF       59   /* spi  [0:0] flag      spi_R1 */