[PATCH v6 3/6] mmc: step power class after final selection of bus mode

[Seungwon Jeon <tgih.jun@samsung.com>]

Power class is changed once only after selection of bus modes
including speed and bus-width finishes finally.

Signed-off-by: Seungwon Jeon <tgih.jun@samsung.com>
Tested-by: Jaehoon Chung <jh80.chung@samsung.com>
Acked-by: Jaehoon Chung <jh80.chung@samsung.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
---
 drivers/mmc/core/mmc.c |   96 +++++++++++++++++++++++++++--------------------
 1 files changed, 55 insertions(+), 41 deletions(-)

diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 97f1912..480c100 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -732,17 +732,13 @@ static struct device_type mmc_type = {
  * extended CSD register, select it by executing the
  * mmc_switch command.
  */
-static int mmc_select_powerclass(struct mmc_card *card,
-		unsigned int bus_width)
+static int __mmc_select_powerclass(struct mmc_card *card,
+				   unsigned int bus_width)
 {
-	int err = 0;
+	struct mmc_host *host = card->host;
+	struct mmc_ext_csd *ext_csd = &card->ext_csd;
 	unsigned int pwrclass_val = 0;
-	struct mmc_host *host;
-
-	BUG_ON(!card);
-
-	host = card->host;
-	BUG_ON(!host);
+	int err = 0;
 
 	/* Power class selection is supported for versions >= 4.0 */
 	if (card->csd.mmca_vsn < CSD_SPEC_VER_4)
@@ -754,14 +750,14 @@ static int mmc_select_powerclass(struct mmc_card *card,
 
 	switch (1 << host->ios.vdd) {
 	case MMC_VDD_165_195:
-		if (host->ios.clock <= 26000000)
-			pwrclass_val = card->ext_csd.raw_pwr_cl_26_195;
-		else if	(host->ios.clock <= 52000000)
+		if (host->ios.clock <= MMC_HIGH_26_MAX_DTR)
+			pwrclass_val = ext_csd->raw_pwr_cl_26_195;
+		else if (host->ios.clock <= MMC_HIGH_52_MAX_DTR)
 			pwrclass_val = (bus_width <= EXT_CSD_BUS_WIDTH_8) ?
-				card->ext_csd.raw_pwr_cl_52_195 :
-				card->ext_csd.raw_pwr_cl_ddr_52_195;
-		else if (host->ios.clock <= 200000000)
-			pwrclass_val = card->ext_csd.raw_pwr_cl_200_195;
+				ext_csd->raw_pwr_cl_52_195 :
+				ext_csd->raw_pwr_cl_ddr_52_195;
+		else if (host->ios.clock <= MMC_HS200_MAX_DTR)
+			pwrclass_val = ext_csd->raw_pwr_cl_200_195;
 		break;
 	case MMC_VDD_27_28:
 	case MMC_VDD_28_29:
@@ -772,14 +768,14 @@ static int mmc_select_powerclass(struct mmc_card *card,
 	case MMC_VDD_33_34:
 	case MMC_VDD_34_35:
 	case MMC_VDD_35_36:
-		if (host->ios.clock <= 26000000)
-			pwrclass_val = card->ext_csd.raw_pwr_cl_26_360;
-		else if	(host->ios.clock <= 52000000)
+		if (host->ios.clock <= MMC_HIGH_26_MAX_DTR)
+			pwrclass_val = ext_csd->raw_pwr_cl_26_360;
+		else if (host->ios.clock <= MMC_HIGH_52_MAX_DTR)
 			pwrclass_val = (bus_width <= EXT_CSD_BUS_WIDTH_8) ?
-				card->ext_csd.raw_pwr_cl_52_360 :
-				card->ext_csd.raw_pwr_cl_ddr_52_360;
-		else if (host->ios.clock <= 200000000)
-			pwrclass_val = card->ext_csd.raw_pwr_cl_200_360;
+				ext_csd->raw_pwr_cl_52_360 :
+				ext_csd->raw_pwr_cl_ddr_52_360;
+		else if (host->ios.clock <= MMC_HS200_MAX_DTR)
+			pwrclass_val = ext_csd->raw_pwr_cl_200_360;
 		break;
 	default:
 		pr_warning("%s: Voltage range not supported "
@@ -805,6 +801,37 @@ static int mmc_select_powerclass(struct mmc_card *card,
 	return err;
 }
 
+static int mmc_select_powerclass(struct mmc_card *card)
+{
+	struct mmc_host *host = card->host;
+	u32 bus_width, ext_csd_bits;
+	int err, ddr;
+
+	/* Power class selection is supported for versions >= 4.0 */
+	if (card->csd.mmca_vsn < CSD_SPEC_VER_4)
+		return 0;
+
+	bus_width = host->ios.bus_width;
+	/* Power class values are defined only for 4/8 bit bus */
+	if (bus_width == MMC_BUS_WIDTH_1)
+		return 0;
+
+	ddr = card->mmc_avail_type & EXT_CSD_CARD_TYPE_DDR_52;
+	if (ddr)
+		ext_csd_bits = (bus_width == MMC_BUS_WIDTH_8) ?
+			EXT_CSD_DDR_BUS_WIDTH_8 : EXT_CSD_DDR_BUS_WIDTH_4;
+	else
+		ext_csd_bits = (bus_width == MMC_BUS_WIDTH_8) ?
+			EXT_CSD_BUS_WIDTH_8 :  EXT_CSD_BUS_WIDTH_4;
+
+	err = __mmc_select_powerclass(card, ext_csd_bits);
+	if (err)
+		pr_warn("%s: power class selection to bus width %d ddr %d failed\n",
+			mmc_hostname(host), 1 << bus_width, ddr);
+
+	return err;
+}
+
 /*
  * Selects the desired buswidth and switch to the HS200 mode
  * if bus width set without error
@@ -1166,11 +1193,6 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
 
 		ext_csd_bits = (bus_width == MMC_BUS_WIDTH_8) ?
 				EXT_CSD_BUS_WIDTH_8 : EXT_CSD_BUS_WIDTH_4;
-		err = mmc_select_powerclass(card, ext_csd_bits);
-		if (err)
-			pr_warning("%s: power class selection to bus width %d"
-				   " failed\n", mmc_hostname(card->host),
-				   1 << bus_width);
 	}
 
 	/*
@@ -1199,12 +1221,6 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
 			bus_width = bus_widths[idx];
 			if (bus_width == MMC_BUS_WIDTH_1)
 				ddr = 0; /* no DDR for 1-bit width */
-			err = mmc_select_powerclass(card, ext_csd_bits[idx][0]);
-			if (err)
-				pr_warning("%s: power class selection to "
-					   "bus width %d failed\n",
-					   mmc_hostname(card->host),
-					   1 << bus_width);
 
 			err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
 					 EXT_CSD_BUS_WIDTH,
@@ -1229,13 +1245,6 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
 		}
 
 		if (!err && ddr) {
-			err = mmc_select_powerclass(card, ext_csd_bits[idx][1]);
-			if (err)
-				pr_warning("%s: power class selection to "
-					   "bus width %d ddr %d failed\n",
-					   mmc_hostname(card->host),
-					   1 << bus_width, ddr);
-
 			err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
 					 EXT_CSD_BUS_WIDTH,
 					 ext_csd_bits[idx][1],
@@ -1273,6 +1282,11 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
 	}
 
 	/*
+	 * Choose the power class with selected bus interface
+	 */
+	mmc_select_powerclass(card);
+
+	/*
 	 * Enable HPI feature (if supported)
 	 */
 	if (card->ext_csd.hpi) {
-- 
1.7.0.4