[U-Boot] [PATCH 15/22] mmc: add a new mmc parameter to disable mmc clock

Jean-Jacques Hiblot jjhiblot at ti.com
Fri May 12 18:16:33 UTC 2017


mmc clock has to be disabled in certain cases like during
the voltage switch sequence. Modify mmc_set_clock function
to take disable as an argument that signifies if the
clock has to be enabled or disabled.

Signed-off-by: Kishon Vijay Abraham I <kishon at ti.com>
Signed-off-by: Jean-Jacques Hiblot <jjhiblot at ti.com>
---
 drivers/mmc/fsl_esdhc.c |  2 +-
 drivers/mmc/mmc.c       | 11 ++++++-----
 include/mmc.h           |  3 ++-
 3 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/drivers/mmc/fsl_esdhc.c b/drivers/mmc/fsl_esdhc.c
index f3c6358..b631392 100644
--- a/drivers/mmc/fsl_esdhc.c
+++ b/drivers/mmc/fsl_esdhc.c
@@ -658,7 +658,7 @@ static int esdhc_init(struct mmc *mmc)
 #endif
 
 	/* Set the initial clock speed */
-	mmc_set_clock(mmc, 400000);
+	mmc_set_clock(mmc, 400000, false);
 
 	/* Disable the BRR and BWR bits in IRQSTAT */
 	esdhc_clrbits32(&regs->irqstaten, IRQSTATEN_BRR | IRQSTATEN_BWR);
diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c
index 032260b..70b7d19 100644
--- a/drivers/mmc/mmc.c
+++ b/drivers/mmc/mmc.c
@@ -1216,7 +1216,7 @@ static int mmc_set_ios(struct mmc *mmc)
 }
 #endif
 
-int mmc_set_clock(struct mmc *mmc, uint clock)
+int mmc_set_clock(struct mmc *mmc, uint clock, u8 disable)
 {
 	if (clock > mmc->cfg->f_max)
 		clock = mmc->cfg->f_max;
@@ -1225,6 +1225,7 @@ int mmc_set_clock(struct mmc *mmc, uint clock)
 		clock = mmc->cfg->f_min;
 
 	mmc->clock = clock;
+	mmc->clk_disable = disable;
 
 	return mmc_set_ios(mmc);
 }
@@ -1316,7 +1317,7 @@ static int sd_select_mode_and_width(struct mmc *mmc)
 
 				/* configure the bus mode (host) */
 				mmc_select_mode(mmc, mwt->mode);
-				mmc_set_clock(mmc, mmc->tran_speed);
+				mmc_set_clock(mmc, mmc->tran_speed, false);
 
 				err = sd_read_ssr(mmc);
 				if (!err)
@@ -1327,7 +1328,7 @@ static int sd_select_mode_and_width(struct mmc *mmc)
 error:
 				/* revert to a safer bus speed */
 				mmc_select_mode(mmc, SD_LEGACY);
-				mmc_set_clock(mmc, mmc->tran_speed);
+				mmc_set_clock(mmc, mmc->tran_speed, false);
 			}
 		}
 	}
@@ -1465,7 +1466,7 @@ static int mmc_select_mode_and_width(struct mmc *mmc)
 
 			/* configure the bus mode (host) */
 			mmc_select_mode(mmc, mwt->mode);
-			mmc_set_clock(mmc, mmc->tran_speed);
+			mmc_set_clock(mmc, mmc->tran_speed, false);
 
 			/* do a transfer to check the configuration */
 			err = mmc_read_and_compare_ext_csd(mmc);
@@ -1928,7 +1929,7 @@ static void mmc_set_initial_state(struct mmc *mmc)
 		printf("failed to set signal voltage\n");
 
 	mmc_set_bus_width(mmc, 1);
-	mmc_set_clock(mmc, 1);
+	mmc_set_clock(mmc, 1, false);
 	mmc_select_mode(mmc, MMC_LEGACY);
 }
 
diff --git a/include/mmc.h b/include/mmc.h
index 43d37a4..097a685 100644
--- a/include/mmc.h
+++ b/include/mmc.h
@@ -466,6 +466,7 @@ struct mmc {
 	void *priv;
 	uint has_init;
 	int high_capacity;
+	u8 clk_disable;
 	uint bus_width;
 	uint clock;
 	uint signal_voltage;
@@ -557,7 +558,7 @@ int mmc_unbind(struct udevice *dev);
 int mmc_initialize(bd_t *bis);
 int mmc_init(struct mmc *mmc);
 int mmc_read(struct mmc *mmc, u64 src, uchar *dst, int size);
-int mmc_set_clock(struct mmc *mmc, uint clock);
+int mmc_set_clock(struct mmc *mmc, uint clock, u8 disable);
 struct mmc *find_mmc_device(int dev_num);
 int mmc_set_dev(int dev_num);
 void print_mmc_devices(char separator);
-- 
1.9.1



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