mmc: core: add core-level function for sending tuning commands

According to the SD card spec, Add a manual tuning command function
for SDR104/HS200.
Sending command 19 or command 21 to read data and compare with the
tunning block pattern.

This patch will help to decrease some platform private codes in SDHCI
platform_execute_tuning() callbacks.

Signed-off-by: Minda Chen <Minda.Chen@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

diff --git a/drivers/mmc/core/mmc_ops.c b/drivers/mmc/core/mmc_ops.c
index 23aa3a3..12b2a32 100644 (file)
--- a/drivers/mmc/core/mmc_ops.c
+++ b/drivers/mmc/core/mmc_ops.c
@@ -547,6 +547,76 @@ int mmc_switch(struct mmc_card *card, u8 set, u8 index, u8 value,
 }
 EXPORT_SYMBOL_GPL(mmc_switch);
 
+int mmc_send_tuning(struct mmc_card *card)
+{
+       struct mmc_request mrq = {NULL};
+       struct mmc_command cmd = {0};
+       struct mmc_data data = {0};
+       struct scatterlist sg;
+       struct mmc_host *mmc = card->host;
+       struct mmc_ios *ios = &mmc->ios;
+       const u8 *tuning_block_pattern;
+       int size, err = 0;
+       u8 *data_buf;
+       u32 opcode;
+
+       if (ios->bus_width == MMC_BUS_WIDTH_8) {
+               tuning_block_pattern = tuning_blk_pattern_8bit;
+               size = sizeof(tuning_blk_pattern_8bit);
+               opcode = MMC_SEND_TUNING_BLOCK_HS200;
+       } else if (ios->bus_width == MMC_BUS_WIDTH_4) {
+               tuning_block_pattern = tuning_blk_pattern_4bit;
+               size = sizeof(tuning_blk_pattern_4bit);
+               opcode = MMC_SEND_TUNING_BLOCK;
+       } else
+               return -EINVAL;
+
+       data_buf = kzalloc(size, GFP_KERNEL);
+       if (!data_buf)
+               return -ENOMEM;
+
+       mrq.cmd = &cmd;
+       mrq.data = &data;
+
+       cmd.opcode = opcode;
+       cmd.flags = MMC_RSP_R1 | MMC_CMD_ADTC;
+
+       data.blksz = size;
+       data.blocks = 1;
+       data.flags = MMC_DATA_READ;
+
+       /*
+        * According to the tuning specs, Tuning process
+        * is normally shorter 40 executions of CMD19,
+        * and timeout value should be shorter than 150 ms
+        */
+       data.timeout_ns = 150 * NSEC_PER_MSEC;
+
+       data.sg = &sg;
+       data.sg_len = 1;
+       sg_init_one(&sg, data_buf, size);
+
+       mmc_wait_for_req(mmc, &mrq);
+
+       if (cmd.error) {
+               err = cmd.error;
+               goto out;
+       }
+
+       if (data.error) {
+               err = data.error;
+               goto out;
+       }
+
+       if (memcmp(data_buf, tuning_block_pattern, size))
+               err = -EIO;
+
+out:
+       kfree(data_buf);
+       return err;
+}
+EXPORT_SYMBOL_GPL(mmc_send_tuning);
+
 static int
 mmc_send_bus_test(struct mmc_card *card, struct mmc_host *host, u8 opcode,
                  u8 len)

diff --git a/include/linux/mmc/core.h b/include/linux/mmc/core.h
index b11e43c..c4bdaa1 100644 (file)
--- a/include/linux/mmc/core.h
+++ b/include/linux/mmc/core.h
@@ -154,6 +154,7 @@ extern void mmc_start_bkops(struct mmc_card *card, bool from_exception);
 extern int __mmc_switch(struct mmc_card *, u8, u8, u8, unsigned int, bool,
                        bool, bool);
 extern int mmc_switch(struct mmc_card *, u8, u8, u8, unsigned int);
+extern int mmc_send_tuning(struct mmc_card *card);
 extern int mmc_get_ext_csd(struct mmc_card *card, u8 **new_ext_csd);
 
 #define MMC_ERASE_ARG          0x00000000