Change from previous patch;
Added MMC_RSP_SPI_R1 to mmc_ops command for DATA_READ and DATA_Write
(Thanks to Takashi Lwai for pointing this out)
Patch made against linux-next (see below) and tested against marvell mmp2
controller using Marvell linux
eMMC cards do not have a card specific field indicating the bus width that
they support.
The bus width needs to be figured out by probing the bus.
JEDEC STANDARD
Embedded MultiMediaCard(e•MMC) e•MMC/Card Product Standard, High Capacity,
including Reliable Write, Boot, Sleep Modes, Dual Data Rate,
Multiple Partitions Supports, Security Enhancement, Background Operation and
High Priority Interrupt (MMCA, 4.41)
JESD84-A441
defines what needs to be done in Annex A.8.3.
In earlier testing (2.6.2x) this code did not work on some PCIe SD controllers.
We define a new MMC_CAP: MMC_CAP_BUS_WIDTH_WORKS that the host adaptation
layer can set if the controller can support bus width testing.
If the CAP is not defined the behavior defaults to what is done today;
the largest bit width is selected.
Transcend 1GB and 2GB MMC cards work when this code is enabled and fail otherwise.
Signed-off-by: Philip Rakity <prakity@xxxxxxxxxxx>
---
drivers/mmc/core/mmc.c | 47 +++++++++++++++-
drivers/mmc/core/mmc_ops.c | 132 ++++++++++++++++++++++++++++++++++++++++++++
drivers/mmc/core/mmc_ops.h | 1 +
include/linux/mmc/host.h | 1 +
include/linux/mmc/mmc.h | 2 +
5 files changed, 182 insertions(+), 1 deletions(-)
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 */
--
1.6.0.4
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