[PATCH v5 00/13] Add Qualcomm SD Card Controller support

[PATCH v5 00/13] Add Qualcomm SD Card Controller support

[srinivas.kandagatla]

From: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>

Thankyou Linus W, Ulf H and everyone for reviewing RFC to v4 patches.

This patch series adds Qualcomm SD Card Controller support in pl180 mmci
driver. QCom SDCC is basically a pl180, but bit more customized, some of the
register layouts and offsets are different to the ones mentioned in pl180
datasheet. The plan is to totally remove the standalone SDCC driver
drivers/mmc/host/msm_sdcc.* and start using generic mmci driver for all
Qualcomm parts, as we get chance to test on other Qcom boards.

To start using the existing mmci driver, a fake amba id for Qualcomm is added
in patches:
 mmc: mmci: Add Qualcomm specific register defines.
 mmc: mmci: Add Qualcomm Id to amba id table.

Second change is, adding a 3 clock cycle delay in between writes to
CLKCTRL/POWER/DATACTRL/COMMAND registers. Most of the delays are taken care with
the existing driver except delay for the COMMAND register was too small. 
This patch fixes it.
  mmc: mmci: Add enough delay between writes to CMD register.

Third change is to accommodate CLK, DATCTRL and MMCICLK register layout changes
in Qcom SDCC and provide more flexibity in driver to specify these changes via
variant datastructure. Which are done in patches:
  mmc: mmci: Add Qcom datactrl register variant
  mmc: mmci: add ddrmode mask to variant data
  mmc: mmci: add 8bit bus support in variant data
  mmc: mmci: add edge support to data and command out in variant data.
  mmc: mmci: add Qcom specifics of clk and datactrl registers.
  mmc: mmci: Add support to data commands via variant structure.
  mmc: mmci: add f_max to variant structure
  mmc: mmci: add explicit clk control

Fourth change was to add qcom specfic fifocnt logic, the need for
this is because the way MCIFIFOCNT register behaved in QCOM SDCC is very
 different to the one in pl180. This change is done in patch:
  mmc: mmci: Add Qcom specific rx_fifocnt logic.

Last some Qcom unrelated changes/cleanup to driver are done in patches:
  mmc: mmci: use NSEC_PER_SEC macro
  mmc: mmci: convert register bits to use BIT() macro.

This patches are tested in PIO mode on IFC8064 board with both eMMC and
external SD card. I would like to get this support in v3.16.

Changes from v4:
	- moved the amba id table addition to the end of the patchset as suggested by Ulf.
	- reused the mmci_pio_read function after experimenting with the fifo behaviour.
	- simplify f_max/f_min calculation logic as suggested by Ulf.
	- created a new patch for the register defination as suggested by Ulf.

Changes from v3:
	- moved pio_read to a function pointer so as to reduce additional cycles
	in hot-path, suggested by Ulf.
	- simplify the flags used for explicit mclk control, suggested by Ulf.
	- fixed issues in cacluating f_max and f_min pointed and suggested by Ulf.
	- removed unessary DDR flags on un-supported STE variants.
	- used BIT macros as suggested by Ulf.
	- removed the read/write wrappers with delays, and used most optimal way
	to introduce the delays to the only registers that require delays.

Changes from v2:
	- merged fbclk latch patch with clkreg_enable patch as suggested by Linus W.
	- remove qcom prefix for explicit clk control pointed by Linus W.
	- cleaned up mmci_qcom_pio_read and consider SDIO as suggested by Linus W.

Changes from v1:
	- moved most of the SOC specifics to variant parameters as suggested
	  by Linus W.
	- renamed registers as suggested by Linus W.
	- Added comments in the code as suggested by Linus W.
	- moved out AMBA ID addition patch from this series.
	- rebased the patches to 
		git://git.linaro.org/people/ulf.hansson/mmc.git next 
	  as suggested by Ulf H.

Changes from RFC:
	- moved out clk setup out of spinlock as pointed by Stephen B.

Am hoping to get this for v3.16.

All these patches are tested on IF6410 board on both eMMC and external SD card.

Thanks,
srini

Srinivas Kandagatla (13):
  mmc: mmci: use NSEC_PER_SEC macro
  mmc: mmci: convert register bits to use BIT() macro.
  mmc: mmci: Add Qualcomm specific register defines.
  mmc: mmci: Add enough delay between writes to CMD register.
  mmc: mmci: Add Qcom datactrl register variant
  mmc: mmci: add ddrmode mask to variant data
  mmc: mmci: add 8bit bus support in variant data
  mmc: mmci: add edge support to data and command out in variant data.
  mmc: mmci: Add support to data commands via variant structure.
  mmc: mmci: add f_max to variant structure
  mmc: mmci: add explicit clk control
  mmc: mmci: Add Qcom specific rx_fifocnt logic.
  mmc: mmci: Add Qualcomm Id to amba id table

 drivers/mmc/host/mmci.c | 129 ++++++++++++++++++++++++---
 drivers/mmc/host/mmci.h | 228 ++++++++++++++++++++++++++----------------------
 2 files changed, 241 insertions(+), 116 deletions(-)

-- 
1.9.1

[PATCH v5 01/13] mmc: mmci: use NSEC_PER_SEC macro

[srinivas.kandagatla]

From: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>

This patch replaces a constant used in calculating timeout with a proper
macro. This is make code more readable.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
---
 drivers/mmc/host/mmci.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index a084edd..a38e714 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -718,7 +718,7 @@ static void mmci_start_data(struct mmci_host *host, struct mmc_data *data)
 	data->bytes_xfered = 0;
 
 	clks = (unsigned long long)data->timeout_ns * host->cclk;
-	do_div(clks, 1000000000UL);
+	do_div(clks, NSEC_PER_SEC);
 
 	timeout = data->timeout_clks + (unsigned int)clks;
 
-- 
1.9.1

[PATCH v5 02/13] mmc: mmci: convert register bits to use BIT() macro.

[srinivas.kandagatla]

From: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>

This patch converts the register bits in the header file to use BIT(()
macro, which looks much neater.

No functional changes done.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
---
 drivers/mmc/host/mmci.h | 208 ++++++++++++++++++++++++------------------------
 1 file changed, 104 insertions(+), 104 deletions(-)

diff --git a/drivers/mmc/host/mmci.h b/drivers/mmc/host/mmci.h
index 347d942..cd83ca3 100644
--- a/drivers/mmc/host/mmci.h
+++ b/drivers/mmc/host/mmci.h
@@ -11,48 +11,48 @@
 #define MCI_PWR_OFF		0x00
 #define MCI_PWR_UP		0x02
 #define MCI_PWR_ON		0x03
-#define MCI_OD			(1 << 6)
-#define MCI_ROD			(1 << 7)
+#define MCI_OD			BIT(6)
+#define MCI_ROD			BIT(7)
 /*
  * The ST Micro version does not have ROD and reuse the voltage registers for
  * direction settings.
  */
-#define MCI_ST_DATA2DIREN	(1 << 2)
-#define MCI_ST_CMDDIREN		(1 << 3)
-#define MCI_ST_DATA0DIREN	(1 << 4)
-#define MCI_ST_DATA31DIREN	(1 << 5)
-#define MCI_ST_FBCLKEN		(1 << 7)
-#define MCI_ST_DATA74DIREN	(1 << 8)
+#define MCI_ST_DATA2DIREN	BIT(2)
+#define MCI_ST_CMDDIREN		BIT(3)
+#define MCI_ST_DATA0DIREN	BIT(4)
+#define MCI_ST_DATA31DIREN	BIT(5)
+#define MCI_ST_FBCLKEN		BIT(7)
+#define MCI_ST_DATA74DIREN	BIT(8)
 
 #define MMCICLOCK		0x004
-#define MCI_CLK_ENABLE		(1 << 8)
-#define MCI_CLK_PWRSAVE		(1 << 9)
-#define MCI_CLK_BYPASS		(1 << 10)
-#define MCI_4BIT_BUS		(1 << 11)
+#define MCI_CLK_ENABLE		BIT(8)
+#define MCI_CLK_PWRSAVE		BIT(9)
+#define MCI_CLK_BYPASS		BIT(10)
+#define MCI_4BIT_BUS		BIT(11)
 /*
  * 8bit wide buses, hardware flow contronl, negative edges and clock inversion
  * supported in ST Micro U300 and Ux500 versions
  */
-#define MCI_ST_8BIT_BUS		(1 << 12)
-#define MCI_ST_U300_HWFCEN	(1 << 13)
-#define MCI_ST_UX500_NEG_EDGE	(1 << 13)
-#define MCI_ST_UX500_HWFCEN	(1 << 14)
-#define MCI_ST_UX500_CLK_INV	(1 << 15)
+#define MCI_ST_8BIT_BUS		BIT(12)
+#define MCI_ST_U300_HWFCEN	BIT(13)
+#define MCI_ST_UX500_NEG_EDGE	BIT(13)
+#define MCI_ST_UX500_HWFCEN	BIT(14)
+#define MCI_ST_UX500_CLK_INV	BIT(15)
 /* Modified PL180 on Versatile Express platform */
-#define MCI_ARM_HWFCEN		(1 << 12)
+#define MCI_ARM_HWFCEN		BIT(12)
 
 #define MMCIARGUMENT		0x008
 #define MMCICOMMAND		0x00c
-#define MCI_CPSM_RESPONSE	(1 << 6)
-#define MCI_CPSM_LONGRSP	(1 << 7)
-#define MCI_CPSM_INTERRUPT	(1 << 8)
-#define MCI_CPSM_PENDING	(1 << 9)
-#define MCI_CPSM_ENABLE		(1 << 10)
+#define MCI_CPSM_RESPONSE	BIT(6)
+#define MCI_CPSM_LONGRSP	BIT(7)
+#define MCI_CPSM_INTERRUPT	BIT(8)
+#define MCI_CPSM_PENDING	BIT(9)
+#define MCI_CPSM_ENABLE		BIT(10)
 /* Argument flag extenstions in the ST Micro versions */
-#define MCI_ST_SDIO_SUSP	(1 << 11)
-#define MCI_ST_ENCMD_COMPL	(1 << 12)
-#define MCI_ST_NIEN		(1 << 13)
-#define MCI_ST_CE_ATACMD	(1 << 14)
+#define MCI_ST_SDIO_SUSP	BIT(11)
+#define MCI_ST_ENCMD_COMPL	BIT(12)
+#define MCI_ST_NIEN		BIT(13)
+#define MCI_ST_CE_ATACMD	BIT(14)
 
 #define MMCIRESPCMD		0x010
 #define MMCIRESPONSE0		0x014
@@ -62,95 +62,95 @@
 #define MMCIDATATIMER		0x024
 #define MMCIDATALENGTH		0x028
 #define MMCIDATACTRL		0x02c
-#define MCI_DPSM_ENABLE		(1 << 0)
-#define MCI_DPSM_DIRECTION	(1 << 1)
-#define MCI_DPSM_MODE		(1 << 2)
-#define MCI_DPSM_DMAENABLE	(1 << 3)
-#define MCI_DPSM_BLOCKSIZE	(1 << 4)
+#define MCI_DPSM_ENABLE		BIT(0)
+#define MCI_DPSM_DIRECTION	BIT(1)
+#define MCI_DPSM_MODE		BIT(2)
+#define MCI_DPSM_DMAENABLE	BIT(3)
+#define MCI_DPSM_BLOCKSIZE	BIT(4)
 /* Control register extensions in the ST Micro U300 and Ux500 versions */
-#define MCI_ST_DPSM_RWSTART	(1 << 8)
-#define MCI_ST_DPSM_RWSTOP	(1 << 9)
-#define MCI_ST_DPSM_RWMOD	(1 << 10)
-#define MCI_ST_DPSM_SDIOEN	(1 << 11)
+#define MCI_ST_DPSM_RWSTART	BIT(8)
+#define MCI_ST_DPSM_RWSTOP	BIT(9)
+#define MCI_ST_DPSM_RWMOD	BIT(10)
+#define MCI_ST_DPSM_SDIOEN	BIT(11)
 /* Control register extensions in the ST Micro Ux500 versions */
-#define MCI_ST_DPSM_DMAREQCTL	(1 << 12)
-#define MCI_ST_DPSM_DBOOTMODEEN	(1 << 13)
-#define MCI_ST_DPSM_BUSYMODE	(1 << 14)
-#define MCI_ST_DPSM_DDRMODE	(1 << 15)
+#define MCI_ST_DPSM_DMAREQCTL	BIT(12)
+#define MCI_ST_DPSM_DBOOTMODEEN	BIT(13)
+#define MCI_ST_DPSM_BUSYMODE	BIT(14)
+#define MCI_ST_DPSM_DDRMODE	BIT(15)
 
 #define MMCIDATACNT		0x030
 #define MMCISTATUS		0x034
-#define MCI_CMDCRCFAIL		(1 << 0)
-#define MCI_DATACRCFAIL		(1 << 1)
-#define MCI_CMDTIMEOUT		(1 << 2)
-#define MCI_DATATIMEOUT		(1 << 3)
-#define MCI_TXUNDERRUN		(1 << 4)
-#define MCI_RXOVERRUN		(1 << 5)
-#define MCI_CMDRESPEND		(1 << 6)
-#define MCI_CMDSENT		(1 << 7)
-#define MCI_DATAEND		(1 << 8)
-#define MCI_STARTBITERR		(1 << 9)
-#define MCI_DATABLOCKEND	(1 << 10)
-#define MCI_CMDACTIVE		(1 << 11)
-#define MCI_TXACTIVE		(1 << 12)
-#define MCI_RXACTIVE		(1 << 13)
-#define MCI_TXFIFOHALFEMPTY	(1 << 14)
-#define MCI_RXFIFOHALFFULL	(1 << 15)
-#define MCI_TXFIFOFULL		(1 << 16)
-#define MCI_RXFIFOFULL		(1 << 17)
-#define MCI_TXFIFOEMPTY		(1 << 18)
-#define MCI_RXFIFOEMPTY		(1 << 19)
-#define MCI_TXDATAAVLBL		(1 << 20)
-#define MCI_RXDATAAVLBL		(1 << 21)
+#define MCI_CMDCRCFAIL		BIT(0)
+#define MCI_DATACRCFAIL		BIT(1)
+#define MCI_CMDTIMEOUT		BIT(2)
+#define MCI_DATATIMEOUT		BIT(3)
+#define MCI_TXUNDERRUN		BIT(4)
+#define MCI_RXOVERRUN		BIT(5)
+#define MCI_CMDRESPEND		BIT(6)
+#define MCI_CMDSENT		BIT(7)
+#define MCI_DATAEND		BIT(8)
+#define MCI_STARTBITERR		BIT(9)
+#define MCI_DATABLOCKEND	BIT(10)
+#define MCI_CMDACTIVE		BIT(11)
+#define MCI_TXACTIVE		BIT(12)
+#define MCI_RXACTIVE		BIT(13)
+#define MCI_TXFIFOHALFEMPTY	BIT(14)
+#define MCI_RXFIFOHALFFULL	BIT(15)
+#define MCI_TXFIFOFULL		BIT(16)
+#define MCI_RXFIFOFULL		BIT(17)
+#define MCI_TXFIFOEMPTY		BIT(18)
+#define MCI_RXFIFOEMPTY		BIT(19)
+#define MCI_TXDATAAVLBL		BIT(20)
+#define MCI_RXDATAAVLBL		BIT(21)
 /* Extended status bits for the ST Micro variants */
-#define MCI_ST_SDIOIT		(1 << 22)
-#define MCI_ST_CEATAEND		(1 << 23)
-#define MCI_ST_CARDBUSY		(1 << 24)
+#define MCI_ST_SDIOIT		BIT(22)
+#define MCI_ST_CEATAEND		BIT(23)
+#define MCI_ST_CARDBUSY		BIT(24)
 
 #define MMCICLEAR		0x038
-#define MCI_CMDCRCFAILCLR	(1 << 0)
-#define MCI_DATACRCFAILCLR	(1 << 1)
-#define MCI_CMDTIMEOUTCLR	(1 << 2)
-#define MCI_DATATIMEOUTCLR	(1 << 3)
-#define MCI_TXUNDERRUNCLR	(1 << 4)
-#define MCI_RXOVERRUNCLR	(1 << 5)
-#define MCI_CMDRESPENDCLR	(1 << 6)
-#define MCI_CMDSENTCLR		(1 << 7)
-#define MCI_DATAENDCLR		(1 << 8)
-#define MCI_STARTBITERRCLR	(1 << 9)
-#define MCI_DATABLOCKENDCLR	(1 << 10)
+#define MCI_CMDCRCFAILCLR	BIT(0)
+#define MCI_DATACRCFAILCLR	BIT(1)
+#define MCI_CMDTIMEOUTCLR	BIT(2)
+#define MCI_DATATIMEOUTCLR	BIT(3)
+#define MCI_TXUNDERRUNCLR	BIT(4)
+#define MCI_RXOVERRUNCLR	BIT(5)
+#define MCI_CMDRESPENDCLR	BIT(6)
+#define MCI_CMDSENTCLR		BIT(7)
+#define MCI_DATAENDCLR		BIT(8)
+#define MCI_STARTBITERRCLR	BIT(9)
+#define MCI_DATABLOCKENDCLR	BIT(10)
 /* Extended status bits for the ST Micro variants */
-#define MCI_ST_SDIOITC		(1 << 22)
-#define MCI_ST_CEATAENDC	(1 << 23)
-#define MCI_ST_BUSYENDC		(1 << 24)
+#define MCI_ST_SDIOITC		BIT(22)
+#define MCI_ST_CEATAENDC	BIT(23)
+#define MCI_ST_BUSYENDC		BIT(24)
 
 #define MMCIMASK0		0x03c
-#define MCI_CMDCRCFAILMASK	(1 << 0)
-#define MCI_DATACRCFAILMASK	(1 << 1)
-#define MCI_CMDTIMEOUTMASK	(1 << 2)
-#define MCI_DATATIMEOUTMASK	(1 << 3)
-#define MCI_TXUNDERRUNMASK	(1 << 4)
-#define MCI_RXOVERRUNMASK	(1 << 5)
-#define MCI_CMDRESPENDMASK	(1 << 6)
-#define MCI_CMDSENTMASK		(1 << 7)
-#define MCI_DATAENDMASK		(1 << 8)
-#define MCI_STARTBITERRMASK	(1 << 9)
-#define MCI_DATABLOCKENDMASK	(1 << 10)
-#define MCI_CMDACTIVEMASK	(1 << 11)
-#define MCI_TXACTIVEMASK	(1 << 12)
-#define MCI_RXACTIVEMASK	(1 << 13)
-#define MCI_TXFIFOHALFEMPTYMASK	(1 << 14)
-#define MCI_RXFIFOHALFFULLMASK	(1 << 15)
-#define MCI_TXFIFOFULLMASK	(1 << 16)
-#define MCI_RXFIFOFULLMASK	(1 << 17)
-#define MCI_TXFIFOEMPTYMASK	(1 << 18)
-#define MCI_RXFIFOEMPTYMASK	(1 << 19)
-#define MCI_TXDATAAVLBLMASK	(1 << 20)
-#define MCI_RXDATAAVLBLMASK	(1 << 21)
+#define MCI_CMDCRCFAILMASK	BIT(0)
+#define MCI_DATACRCFAILMASK	BIT(1)
+#define MCI_CMDTIMEOUTMASK	BIT(2)
+#define MCI_DATATIMEOUTMASK	BIT(3)
+#define MCI_TXUNDERRUNMASK	BIT(4)
+#define MCI_RXOVERRUNMASK	BIT(5)
+#define MCI_CMDRESPENDMASK	BIT(6)
+#define MCI_CMDSENTMASK		BIT(7)
+#define MCI_DATAENDMASK		BIT(8)
+#define MCI_STARTBITERRMASK	BIT(9)
+#define MCI_DATABLOCKENDMASK	BIT(10)
+#define MCI_CMDACTIVEMASK	BIT(11)
+#define MCI_TXACTIVEMASK	BIT(12)
+#define MCI_RXACTIVEMASK	BIT(13)
+#define MCI_TXFIFOHALFEMPTYMASK	BIT(14)
+#define MCI_RXFIFOHALFFULLMASK	BIT(15)
+#define MCI_TXFIFOFULLMASK	BIT(16)
+#define MCI_RXFIFOFULLMASK	BIT(17)
+#define MCI_TXFIFOEMPTYMASK	BIT(18)
+#define MCI_RXFIFOEMPTYMASK	BIT(19)
+#define MCI_TXDATAAVLBLMASK	BIT(20)
+#define MCI_RXDATAAVLBLMASK	BIT(21)
 /* Extended status bits for the ST Micro variants */
-#define MCI_ST_SDIOITMASK	(1 << 22)
-#define MCI_ST_CEATAENDMASK	(1 << 23)
-#define MCI_ST_BUSYEND		(1 << 24)
+#define MCI_ST_SDIOITMASK	BIT(22)
+#define MCI_ST_CEATAENDMASK	BIT(23)
+#define MCI_ST_BUSYEND		BIT(24)
 
 #define MMCIMASK1		0x040
 #define MMCIFIFOCNT		0x048
-- 
1.9.1

[PATCH v5 03/13] mmc: mmci: Add Qualcomm specific register defines.

[srinivas.kandagatla]

From: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>

This patch adds a Qualcomm SD Card controller specific register variations
to header file. Qualcomm SDCC controller is pl180, with slight changes in
the register layout from standard pl180 register set.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
---
 drivers/mmc/host/mmci.h | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/drivers/mmc/host/mmci.h b/drivers/mmc/host/mmci.h
index cd83ca3..706eb513 100644
--- a/drivers/mmc/host/mmci.h
+++ b/drivers/mmc/host/mmci.h
@@ -41,6 +41,15 @@
 /* Modified PL180 on Versatile Express platform */
 #define MCI_ARM_HWFCEN		BIT(12)
 
+/* Modified on Qualcomm Integrations */
+#define MCI_QCOM_CLK_WIDEBUS_8	(BIT(10) | BIT(11))
+#define MCI_QCOM_CLK_FLOWENA	BIT(12)
+#define MCI_QCOM_CLK_INVERTOUT	BIT(13)
+
+/* select in latch data and command in */
+#define MCI_QCOM_CLK_SELECT_IN_FBCLK	BIT(15)
+#define MCI_QCOM_CLK_SELECT_IN_DDR_MODE	(BIT(14) | BIT(15))
+
 #define MMCIARGUMENT		0x008
 #define MMCICOMMAND		0x00c
 #define MCI_CPSM_RESPONSE	BIT(6)
@@ -54,6 +63,14 @@
 #define MCI_ST_NIEN		BIT(13)
 #define MCI_ST_CE_ATACMD	BIT(14)
 
+/* Modified on Qualcomm Integrations */
+#define MCI_QCOM_CSPM_DATCMD		BIT(12)
+#define MCI_QCOM_CSPM_MCIABORT		BIT(13)
+#define MCI_QCOM_CSPM_CCSENABLE		BIT(14)
+#define MCI_QCOM_CSPM_CCSDISABLE	BIT(15)
+#define MCI_QCOM_CSPM_AUTO_CMD19	BIT(16)
+#define MCI_QCOM_CSPM_AUTO_CMD21	BIT(21)
+
 #define MMCIRESPCMD		0x010
 #define MMCIRESPONSE0		0x014
 #define MMCIRESPONSE1		0x018
-- 
1.9.1

[PATCH v5 04/13] mmc: mmci: Add enough delay between writes to CMD register.

[srinivas.kandagatla]

From: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>

On Qcom SD Card controller POWER, CLKCTRL, DATACTRL and COMMAND registers
should be updated in MCLK domain, and writes to these registers must be
separated by three MCLK cycles. This resitriction is not applicable for
other registers. Any subsequent writes to these register will be ignored
until 3 MCLK have passed.

One usec delay between two CMD register writes is not sufficient in the
card identification phase where the CCLK is very low. This patch replaces
a static 1 usec delay to use mmci_reg_delay function which can provide
correct delay depending on the cclk frequency.

Without this patch the card is not detected.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
---
 drivers/mmc/host/mmci.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index a38e714..ed20bf5 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -810,7 +810,7 @@ mmci_start_command(struct mmci_host *host, struct mmc_command *cmd, u32 c)
 
 	if (readl(base + MMCICOMMAND) & MCI_CPSM_ENABLE) {
 		writel(0, base + MMCICOMMAND);
-		udelay(1);
+		mmci_reg_delay(host);
 	}
 
 	c |= cmd->opcode | MCI_CPSM_ENABLE;
-- 
1.9.1

[PATCH v5 05/13] mmc: mmci: Add Qcom datactrl register variant

[srinivas.kandagatla]

From: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>

Instance of this IP on Qualcomm's SOCs has bit different layout for datactrl
register. Bit position datactrl[16:4] hold the true block size instead of power
of 2.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
---
 drivers/mmc/host/mmci.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index ed20bf5..72981f6 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -60,6 +60,8 @@ static unsigned int fmax = 515633;
  * @sdio: variant supports SDIO
  * @st_clkdiv: true if using a ST-specific clock divider algorithm
  * @blksz_datactrl16: true if Block size is at b16..b30 position in datactrl register
+ * @blksz_datactrl4: true if Block size is at b4..b16 position in datactrl
+ *		     register
  * @pwrreg_powerup: power up value for MMCIPOWER register
  * @signal_direction: input/out direction of bus signals can be indicated
  * @pwrreg_clkgate: MMCIPOWER register must be used to gate the clock
@@ -75,6 +77,7 @@ struct variant_data {
 	bool			sdio;
 	bool			st_clkdiv;
 	bool			blksz_datactrl16;
+	bool			blksz_datactrl4;
 	u32			pwrreg_powerup;
 	bool			signal_direction;
 	bool			pwrreg_clkgate;
@@ -731,6 +734,8 @@ static void mmci_start_data(struct mmci_host *host, struct mmc_data *data)
 
 	if (variant->blksz_datactrl16)
 		datactrl = MCI_DPSM_ENABLE | (data->blksz << 16);
+	else if (variant->blksz_datactrl4)
+		datactrl = MCI_DPSM_ENABLE | (data->blksz << 4);
 	else
 		datactrl = MCI_DPSM_ENABLE | blksz_bits << 4;
 
-- 
1.9.1

[PATCH v5 06/13] mmc: mmci: add ddrmode mask to variant data

[srinivas.kandagatla]

From: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>

This patch adds ddrmode mask to variant structure giving more flexibility
to the driver to support more SOCs which have different datactrl register
layout.

Without this patch datactrl register is updated with incorrect ddrmode mask,
resulting in failures on Qualcomm SD Card Controller.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
---
 drivers/mmc/host/mmci.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index 72981f6..ad7e538 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -59,6 +59,7 @@ static unsigned int fmax = 515633;
  *		  is asserted (likewise for RX)
  * @sdio: variant supports SDIO
  * @st_clkdiv: true if using a ST-specific clock divider algorithm
+ * @datactrl_mask_ddrmode: ddr mode mask in datactrl register.
  * @blksz_datactrl16: true if Block size is at b16..b30 position in datactrl register
  * @blksz_datactrl4: true if Block size is at b4..b16 position in datactrl
  *		     register
@@ -74,6 +75,7 @@ struct variant_data {
 	unsigned int		datalength_bits;
 	unsigned int		fifosize;
 	unsigned int		fifohalfsize;
+	unsigned int		datactrl_mask_ddrmode;
 	bool			sdio;
 	bool			st_clkdiv;
 	bool			blksz_datactrl16;
@@ -152,6 +154,7 @@ static struct variant_data variant_ux500v2 = {
 	.fifohalfsize		= 8 * 4,
 	.clkreg			= MCI_CLK_ENABLE,
 	.clkreg_enable		= MCI_ST_UX500_HWFCEN,
+	.datactrl_mask_ddrmode	= MCI_ST_DPSM_DDRMODE,
 	.datalength_bits	= 24,
 	.sdio			= true,
 	.st_clkdiv		= true,
@@ -770,7 +773,7 @@ static void mmci_start_data(struct mmci_host *host, struct mmc_data *data)
 		}
 
 	if (host->mmc->ios.timing == MMC_TIMING_UHS_DDR50)
-		datactrl |= MCI_ST_DPSM_DDRMODE;
+		datactrl |= variant->datactrl_mask_ddrmode;
 
 	/*
 	 * Attempt to use DMA operation mode, if this
-- 
1.9.1

[PATCH v5 07/13] mmc: mmci: add 8bit bus support in variant data

[srinivas.kandagatla]

From: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>

This patch adds 8bit bus enable to variant structure giving more flexibility
to the driver to support more SOCs which have different clock register layout.

Without this patch other new SOCs like Qcom will have to add more code
to special case them.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
---
 drivers/mmc/host/mmci.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index ad7e538..fa3ad83 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -52,6 +52,7 @@ static unsigned int fmax = 515633;
  * struct variant_data - MMCI variant-specific quirks
  * @clkreg: default value for MCICLOCK register
  * @clkreg_enable: enable value for MMCICLOCK register
+ * @clkreg_8bit_bus_enable: enable value for 8 bit bus
  * @datalength_bits: number of bits in the MMCIDATALENGTH register
  * @fifosize: number of bytes that can be written when MMCI_TXFIFOEMPTY
  *	      is asserted (likewise for RX)
@@ -72,6 +73,7 @@ static unsigned int fmax = 515633;
 struct variant_data {
 	unsigned int		clkreg;
 	unsigned int		clkreg_enable;
+	unsigned int		clkreg_8bit_bus_enable;
 	unsigned int		datalength_bits;
 	unsigned int		fifosize;
 	unsigned int		fifohalfsize;
@@ -113,6 +115,7 @@ static struct variant_data variant_u300 = {
 	.fifosize		= 16 * 4,
 	.fifohalfsize		= 8 * 4,
 	.clkreg_enable		= MCI_ST_U300_HWFCEN,
+	.clkreg_8bit_bus_enable = MCI_ST_8BIT_BUS,
 	.datalength_bits	= 16,
 	.sdio			= true,
 	.pwrreg_powerup		= MCI_PWR_ON,
@@ -139,6 +142,7 @@ static struct variant_data variant_ux500 = {
 	.fifohalfsize		= 8 * 4,
 	.clkreg			= MCI_CLK_ENABLE,
 	.clkreg_enable		= MCI_ST_UX500_HWFCEN,
+	.clkreg_8bit_bus_enable = MCI_ST_8BIT_BUS,
 	.datalength_bits	= 24,
 	.sdio			= true,
 	.st_clkdiv		= true,
@@ -154,6 +158,7 @@ static struct variant_data variant_ux500v2 = {
 	.fifohalfsize		= 8 * 4,
 	.clkreg			= MCI_CLK_ENABLE,
 	.clkreg_enable		= MCI_ST_UX500_HWFCEN,
+	.clkreg_8bit_bus_enable = MCI_ST_8BIT_BUS,
 	.datactrl_mask_ddrmode	= MCI_ST_DPSM_DDRMODE,
 	.datalength_bits	= 24,
 	.sdio			= true,
@@ -305,7 +310,7 @@ static void mmci_set_clkreg(struct mmci_host *host, unsigned int desired)
 	if (host->mmc->ios.bus_width == MMC_BUS_WIDTH_4)
 		clk |= MCI_4BIT_BUS;
 	if (host->mmc->ios.bus_width == MMC_BUS_WIDTH_8)
-		clk |= MCI_ST_8BIT_BUS;
+		clk |= variant->clkreg_8bit_bus_enable;
 
 	if (host->mmc->ios.timing == MMC_TIMING_UHS_DDR50)
 		clk |= MCI_ST_UX500_NEG_EDGE;
-- 
1.9.1

[PATCH v5 08/13] mmc: mmci: add edge support to data and command out in variant data.

[srinivas.kandagatla]

From: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>

This patch adds edge support for data and command out to variant structure
giving more flexibility to the driver to support more SOCs which have
different clock register layout.

Without this patch other new SOCs like Qcom will have to add more code to
special case them

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
---
 drivers/mmc/host/mmci.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index fa3ad83..4c95a9b 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -53,6 +53,7 @@ static unsigned int fmax = 515633;
  * @clkreg: default value for MCICLOCK register
  * @clkreg_enable: enable value for MMCICLOCK register
  * @clkreg_8bit_bus_enable: enable value for 8 bit bus
+ * @clkreg_neg_edge_enable: enable value for inverted data/cmd output
  * @datalength_bits: number of bits in the MMCIDATALENGTH register
  * @fifosize: number of bytes that can be written when MMCI_TXFIFOEMPTY
  *	      is asserted (likewise for RX)
@@ -74,6 +75,7 @@ struct variant_data {
 	unsigned int		clkreg;
 	unsigned int		clkreg_enable;
 	unsigned int		clkreg_8bit_bus_enable;
+	unsigned int		clkreg_neg_edge_enable;
 	unsigned int		datalength_bits;
 	unsigned int		fifosize;
 	unsigned int		fifohalfsize;
@@ -143,6 +145,7 @@ static struct variant_data variant_ux500 = {
 	.clkreg			= MCI_CLK_ENABLE,
 	.clkreg_enable		= MCI_ST_UX500_HWFCEN,
 	.clkreg_8bit_bus_enable = MCI_ST_8BIT_BUS,
+	.clkreg_neg_edge_enable	= MCI_ST_UX500_NEG_EDGE,
 	.datalength_bits	= 24,
 	.sdio			= true,
 	.st_clkdiv		= true,
@@ -159,6 +162,7 @@ static struct variant_data variant_ux500v2 = {
 	.clkreg			= MCI_CLK_ENABLE,
 	.clkreg_enable		= MCI_ST_UX500_HWFCEN,
 	.clkreg_8bit_bus_enable = MCI_ST_8BIT_BUS,
+	.clkreg_neg_edge_enable	= MCI_ST_UX500_NEG_EDGE,
 	.datactrl_mask_ddrmode	= MCI_ST_DPSM_DDRMODE,
 	.datalength_bits	= 24,
 	.sdio			= true,
@@ -313,7 +317,7 @@ static void mmci_set_clkreg(struct mmci_host *host, unsigned int desired)
 		clk |= variant->clkreg_8bit_bus_enable;
 
 	if (host->mmc->ios.timing == MMC_TIMING_UHS_DDR50)
-		clk |= MCI_ST_UX500_NEG_EDGE;
+		clk |= variant->clkreg_neg_edge_enable;
 
 	mmci_write_clkreg(host, clk);
 }
-- 
1.9.1

[PATCH v5 09/13] mmc: mmci: Add support to data commands via variant structure.

[srinivas.kandagatla]

From: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>

On some SOCs like Qcom there are explicit bits in the command register
to specify if its a data transfer command or not. So this patch adds
support to such bits in variant data, giving more flexibility to the
driver.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
---
 drivers/mmc/host/mmci.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index 4c95a9b..8534c29 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -59,6 +59,7 @@ static unsigned int fmax = 515633;
  *	      is asserted (likewise for RX)
  * @fifohalfsize: number of bytes that can be written when MCI_TXFIFOHALFEMPTY
  *		  is asserted (likewise for RX)
+ * @data_cmd_enable: enable value for data commands.
  * @sdio: variant supports SDIO
  * @st_clkdiv: true if using a ST-specific clock divider algorithm
  * @datactrl_mask_ddrmode: ddr mode mask in datactrl register.
@@ -79,6 +80,7 @@ struct variant_data {
 	unsigned int		datalength_bits;
 	unsigned int		fifosize;
 	unsigned int		fifohalfsize;
+	unsigned int		data_cmd_enable;
 	unsigned int		datactrl_mask_ddrmode;
 	bool			sdio;
 	bool			st_clkdiv;
@@ -839,6 +841,9 @@ mmci_start_command(struct mmci_host *host, struct mmc_command *cmd, u32 c)
 	if (/*interrupt*/0)
 		c |= MCI_CPSM_INTERRUPT;
 
+	if (mmc_cmd_type(cmd) == MMC_CMD_ADTC)
+		c |= host->variant->data_cmd_enable;
+
 	host->cmd = cmd;
 
 	writel(cmd->arg, base + MMCIARGUMENT);
-- 
1.9.1

[PATCH v5 10/13] mmc: mmci: add f_max to variant structure

[srinivas.kandagatla]

From: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>

Some of the controller have maximum supported frequency, This patch adds
support in variant data structure to specify such restrictions. This
gives more flexibility in calculating the f_max before passing it to
mmc-core.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
---
 drivers/mmc/host/mmci.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index 8534c29..55d39d2 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -67,6 +67,7 @@ static unsigned int fmax = 515633;
  * @blksz_datactrl4: true if Block size is at b4..b16 position in datactrl
  *		     register
  * @pwrreg_powerup: power up value for MMCIPOWER register
+ * @f_max: maximum clk frequency supported by the controller.
  * @signal_direction: input/out direction of bus signals can be indicated
  * @pwrreg_clkgate: MMCIPOWER register must be used to gate the clock
  * @busy_detect: true if busy detection on dat0 is supported
@@ -87,6 +88,7 @@ struct variant_data {
 	bool			blksz_datactrl16;
 	bool			blksz_datactrl4;
 	u32			pwrreg_powerup;
+	u32			f_max;
 	bool			signal_direction;
 	bool			pwrreg_clkgate;
 	bool			busy_detect;
@@ -98,6 +100,7 @@ static struct variant_data variant_arm = {
 	.fifohalfsize		= 8 * 4,
 	.datalength_bits	= 16,
 	.pwrreg_powerup		= MCI_PWR_UP,
+	.f_max			= 100000000,
 };
 
 static struct variant_data variant_arm_extended_fifo = {
@@ -105,6 +108,7 @@ static struct variant_data variant_arm_extended_fifo = {
 	.fifohalfsize		= 64 * 4,
 	.datalength_bits	= 16,
 	.pwrreg_powerup		= MCI_PWR_UP,
+	.f_max			= 100000000,
 };
 
 static struct variant_data variant_arm_extended_fifo_hwfc = {
@@ -113,6 +117,7 @@ static struct variant_data variant_arm_extended_fifo_hwfc = {
 	.clkreg_enable		= MCI_ARM_HWFCEN,
 	.datalength_bits	= 16,
 	.pwrreg_powerup		= MCI_PWR_UP,
+	.f_max			= 100000000,
 };
 
 static struct variant_data variant_u300 = {
@@ -123,6 +128,7 @@ static struct variant_data variant_u300 = {
 	.datalength_bits	= 16,
 	.sdio			= true,
 	.pwrreg_powerup		= MCI_PWR_ON,
+	.f_max			= 100000000,
 	.signal_direction	= true,
 	.pwrreg_clkgate		= true,
 	.pwrreg_nopower		= true,
@@ -136,6 +142,7 @@ static struct variant_data variant_nomadik = {
 	.sdio			= true,
 	.st_clkdiv		= true,
 	.pwrreg_powerup		= MCI_PWR_ON,
+	.f_max			= 100000000,
 	.signal_direction	= true,
 	.pwrreg_clkgate		= true,
 	.pwrreg_nopower		= true,
@@ -152,6 +159,7 @@ static struct variant_data variant_ux500 = {
 	.sdio			= true,
 	.st_clkdiv		= true,
 	.pwrreg_powerup		= MCI_PWR_ON,
+	.f_max			= 100000000,
 	.signal_direction	= true,
 	.pwrreg_clkgate		= true,
 	.busy_detect		= true,
@@ -171,6 +179,7 @@ static struct variant_data variant_ux500v2 = {
 	.st_clkdiv		= true,
 	.blksz_datactrl16	= true,
 	.pwrreg_powerup		= MCI_PWR_ON,
+	.f_max			= 100000000,
 	.signal_direction	= true,
 	.pwrreg_clkgate		= true,
 	.busy_detect		= true,
@@ -1471,8 +1480,8 @@ static int mmci_probe(struct amba_device *dev,
 	 * so we try to adjust the clock down to this,
 	 * (if possible).
 	 */
-	if (host->mclk > 100000000) {
-		ret = clk_set_rate(host->clk, 100000000);
+	if (host->mclk > variant->f_max) {
+		ret = clk_set_rate(host->clk, variant->f_max);
 		if (ret < 0)
 			goto clk_disable;
 		host->mclk = clk_get_rate(host->clk);
-- 
1.9.1

[PATCH v5 11/13] mmc: mmci: add explicit clk control

[srinivas.kandagatla]

From: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>

On Controllers like Qcom SD card controller where cclk is mclk and mclk should
be directly controlled by the driver.

This patch adds support to control mclk directly in the driver, and also
adds explicit_mclk_control flag in variant structure giving more flexibility
to the driver.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
---
 drivers/mmc/host/mmci.c | 31 ++++++++++++++++++++++++++++---
 drivers/mmc/host/mmci.h |  2 ++
 2 files changed, 30 insertions(+), 3 deletions(-)

diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index 55d39d2..8b23368 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -72,6 +72,7 @@ static unsigned int fmax = 515633;
  * @pwrreg_clkgate: MMCIPOWER register must be used to gate the clock
  * @busy_detect: true if busy detection on dat0 is supported
  * @pwrreg_nopower: bits in MMCIPOWER don't controls ext. power supply
+ * @explicit_mclk_control: enable explicit mclk control in driver.
  */
 struct variant_data {
 	unsigned int		clkreg;
@@ -93,6 +94,7 @@ struct variant_data {
 	bool			pwrreg_clkgate;
 	bool			busy_detect;
 	bool			pwrreg_nopower;
+	bool			explicit_mclk_control;
 };
 
 static struct variant_data variant_arm = {
@@ -286,7 +288,9 @@ static void mmci_set_clkreg(struct mmci_host *host, unsigned int desired)
 	host->cclk = 0;
 
 	if (desired) {
-		if (desired >= host->mclk) {
+		if (variant->explicit_mclk_control) {
+			host->cclk = host->mclk;
+		} else if (desired >= host->mclk) {
 			clk = MCI_CLK_BYPASS;
 			if (variant->st_clkdiv)
 				clk |= MCI_ST_UX500_NEG_EDGE;
@@ -1325,6 +1329,18 @@ static void mmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 	if (!ios->clock && variant->pwrreg_clkgate)
 		pwr &= ~MCI_PWR_ON;
 
+	if ((host->variant->explicit_mclk_control) &&
+	    (ios->clock != host->clock_cache)) {
+		int rc = clk_set_rate(host->clk, ios->clock);
+		if (rc < 0) {
+			dev_err(mmc_dev(host->mmc),
+				"Error setting clock rate (%d)\n", rc);
+		} else {
+			host->mclk = clk_get_rate(host->clk);
+			host->clock_cache = ios->clock;
+		}
+	}
+
 	spin_lock_irqsave(&host->lock, flags);
 
 	mmci_set_clkreg(host, ios->clock);
@@ -1500,9 +1516,12 @@ static int mmci_probe(struct amba_device *dev,
 	 * The ARM and ST versions of the block have slightly different
 	 * clock divider equations which means that the minimum divider
 	 * differs too.
+	 * on Qualcomm like controllers get the nearest minimum clock to 100Khz
 	 */
 	if (variant->st_clkdiv)
 		mmc->f_min = DIV_ROUND_UP(host->mclk, 257);
+	else if (variant->explicit_mclk_control)
+		mmc->f_min = clk_round_rate(host->clk, 100000);
 	else
 		mmc->f_min = DIV_ROUND_UP(host->mclk, 512);
 	/*
@@ -1512,9 +1531,15 @@ static int mmci_probe(struct amba_device *dev,
 	 * the block, of course.
 	 */
 	if (mmc->f_max)
-		mmc->f_max = min(host->mclk, mmc->f_max);
+		mmc->f_max = variant->explicit_mclk_control ?
+				min(variant->f_max, mmc->f_max) :
+				min(host->mclk, mmc->f_max);
 	else
-		mmc->f_max = min(host->mclk, fmax);
+		mmc->f_max = variant->explicit_mclk_control ?
+				min(variant->f_max, fmax) :
+				min(host->mclk, fmax);
+
+
 	dev_dbg(mmc_dev(mmc), "clocking block at %u Hz\n", mmc->f_max);
 
 	/* Get regulators and the supported OCR mask */
diff --git a/drivers/mmc/host/mmci.h b/drivers/mmc/host/mmci.h
index 706eb513..b5f0810 100644
--- a/drivers/mmc/host/mmci.h
+++ b/drivers/mmc/host/mmci.h
@@ -208,6 +208,8 @@ struct mmci_host {
 	spinlock_t		lock;
 
 	unsigned int		mclk;
+	/* cached value of requested clk in set_ios */
+	unsigned int		clock_cache;
 	unsigned int		cclk;
 	u32			pwr_reg;
 	u32			pwr_reg_add;
-- 
1.9.1

[PATCH v5 12/13] mmc: mmci: Add Qcom specific rx_fifocnt logic.

[srinivas.kandagatla]

From: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>

MCIFIFOCNT register behaviour on Qcom chips is very different than the other
pl180 integrations. MCIFIFOCNT register contains the number of
words that are still waiting to be transferred through the FIFO. It keeps
decrementing once the host CPU reads the MCIFIFO. With the existing logic and
the MCIFIFOCNT behaviour, mmci_pio_read will loop forever, as the FIFOCNT
register will always return transfer size before reading the FIFO.

Also the data sheet states that "This register is only useful for debug
purposes and should not be used for normal operation since it does not reflect
data which may or may not be in the pipeline".

This patch implements a qcom specific get_rx_fifocnt function which is
implemented based on status register flags. Based on qcom_fifo flag in
variant data structure, the corresponding get_rx_fifocnt function is selected.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
---
 drivers/mmc/host/mmci.c | 30 ++++++++++++++++++++++++++++--
 drivers/mmc/host/mmci.h |  1 +
 2 files changed, 29 insertions(+), 2 deletions(-)

diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index 8b23368..7a11522 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -73,6 +73,7 @@ static unsigned int fmax = 515633;
  * @busy_detect: true if busy detection on dat0 is supported
  * @pwrreg_nopower: bits in MMCIPOWER don't controls ext. power supply
  * @explicit_mclk_control: enable explicit mclk control in driver.
+ * @qcom_fifo: enables qcom specific fifo pio read logic.
  */
 struct variant_data {
 	unsigned int		clkreg;
@@ -95,6 +96,7 @@ struct variant_data {
 	bool			busy_detect;
 	bool			pwrreg_nopower;
 	bool			explicit_mclk_control;
+	bool			qcom_fifo;
 };
 
 static struct variant_data variant_arm = {
@@ -990,15 +992,34 @@ mmci_cmd_irq(struct mmci_host *host, struct mmc_command *cmd,
 	}
 }
 
+static int mmci_get_rx_fifocnt(struct mmci_host *host, u32 status, int remain)
+{
+	return remain - (readl(host->base + MMCIFIFOCNT) << 2);
+}
+
+static int mmci_qcom_get_rx_fifocnt(struct mmci_host *host, u32 status, int r)
+{
+	/*
+	 * on qcom SDCC4 only 8 words are used in each burst so only 8 addresses
+	 * from the fifo range should be used
+	 */
+	if (status & MCI_RXFIFOHALFFULL)
+		return host->variant->fifohalfsize;
+	else if (status & MCI_RXDATAAVLBL)
+		return 4;
+
+	return 0;
+}
+
 static int mmci_pio_read(struct mmci_host *host, char *buffer, unsigned int remain)
 {
 	void __iomem *base = host->base;
 	char *ptr = buffer;
-	u32 status;
+	u32 status = readl(host->base + MMCISTATUS);
 	int host_remain = host->size;
 
 	do {
-		int count = host_remain - (readl(base + MMCIFIFOCNT) << 2);
+		int count = host->get_rx_fifocnt(host, status, host_remain);
 
 		if (count > remain)
 			count = remain;
@@ -1488,6 +1509,11 @@ static int mmci_probe(struct amba_device *dev,
 	if (ret)
 		goto host_free;
 
+	if (variant->qcom_fifo)
+		host->get_rx_fifocnt = mmci_qcom_get_rx_fifocnt;
+	else
+		host->get_rx_fifocnt = mmci_get_rx_fifocnt;
+
 	host->plat = plat;
 	host->variant = variant;
 	host->mclk = clk_get_rate(host->clk);
diff --git a/drivers/mmc/host/mmci.h b/drivers/mmc/host/mmci.h
index b5f0810..5f76670 100644
--- a/drivers/mmc/host/mmci.h
+++ b/drivers/mmc/host/mmci.h
@@ -229,6 +229,7 @@ struct mmci_host {
 	/* pio stuff */
 	struct sg_mapping_iter	sg_miter;
 	unsigned int		size;
+	int (*get_rx_fifocnt)(struct mmci_host *h, u32 status, int remain);
 
 #ifdef CONFIG_DMA_ENGINE
 	/* DMA stuff */
-- 
1.9.1

[PATCH v5 13/13] mmc: mmci: Add Qualcomm Id to amba id table

[srinivas.kandagatla]

From: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>

This patch adds a fake Qualcomm ID 0x00051180 to the amba_ids, as Qualcomm
SDCC controller is pl180, but amba id registers read 0x0's.
The plan is to remove SDCC driver totally and use mmci as the main SD
controller driver for Qualcomm SOCs.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
---
 drivers/mmc/host/mmci.c | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index 7a11522..b07c3c3 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -190,6 +190,23 @@ static struct variant_data variant_ux500v2 = {
 	.pwrreg_nopower		= true,
 };
 
+static struct variant_data variant_qcom = {
+	.fifosize		= 16 * 4,
+	.fifohalfsize		= 8 * 4,
+	.clkreg			= MCI_CLK_ENABLE,
+	.clkreg_enable		= MCI_QCOM_CLK_FLOWENA |
+				  MCI_QCOM_CLK_SELECT_IN_FBCLK,
+	.clkreg_8bit_bus_enable = MCI_QCOM_CLK_WIDEBUS_8,
+	.datactrl_mask_ddrmode	= MCI_QCOM_CLK_SELECT_IN_DDR_MODE,
+	.data_cmd_enable	= MCI_QCOM_CSPM_DATCMD,
+	.blksz_datactrl4	= true,
+	.datalength_bits	= 24,
+	.pwrreg_powerup		= MCI_PWR_UP,
+	.f_max			= 208000000,
+	.explicit_mclk_control	= true,
+	.qcom_fifo		= true,
+};
+
 static int mmci_card_busy(struct mmc_host *mmc)
 {
 	struct mmci_host *host = mmc_priv(mmc);
@@ -1832,6 +1849,12 @@ static struct amba_id mmci_ids[] = {
 		.mask   = 0xf0ffffff,
 		.data	= &variant_ux500v2,
 	},
+	/* Qualcomm variants */
+	{
+		.id     = 0x00051180,
+		.mask	= 0x000fffff,
+		.data	= &variant_qcom,
+	},
 	{ 0, 0 },
 };
 
-- 
1.9.1

Re: [PATCH v5 11/13] mmc: mmci: add explicit clk control

[Russell King - ARM Linux]

On Fri, May 30, 2014 at 06:14:40PM +0100, srinivas.kandagatla@linaro.org wrote:
> @@ -1325,6 +1329,18 @@ static void mmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
>  	if (!ios->clock && variant->pwrreg_clkgate)
>  		pwr &= ~MCI_PWR_ON;
>  
> +	if ((host->variant->explicit_mclk_control) &&
> +	    (ios->clock != host->clock_cache)) {

Please explain what use these parens have (or just get rid of them as
they're completely unnecessary - they do nothing for readability.)

In fact, additional useless parens result in readability being harmed.

If you don't know the C precedence rules and as a result feel the need
to litter your code with additional parens, then you really shouldn't
be touching C code in the first place. :)

-- 
FTTC broadband for 0.8mile line: now at 9.7Mbps down 460kbps up... slowly
improving, and getting towards what was expected from it.

Re: [PATCH v5 02/13] mmc: mmci: convert register bits to use BIT() macro.

[Russell King - ARM Linux]

On Fri, May 30, 2014 at 06:13:00PM +0100, srinivas.kandagatla@linaro.org wrote:
> From: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
> 
> This patch converts the register bits in the header file to use BIT(()
> macro, which looks much neater.
> 
> No functional changes done.
> 
> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>

This makes me wonder when we're going to get these definitions in the kernel
source, and have people running around making the conversion:

#define ZERO 0
#define ONE 1
#define TWO 2
#define THREE 3
#define FOUR 4
...

because allegedly it makes it more "readable".  I don't see much benefit
to this patch.

-- 
FTTC broadband for 0.8mile line: now at 9.7Mbps down 460kbps up... slowly
improving, and getting towards what was expected from it.

Re: [PATCH v5 11/13] mmc: mmci: add explicit clk control

[Srinivas Kandagatla]

Thanks Russell,

On 31/05/14 13:29, Russell King - ARM Linux wrote:
>>
>> >+	if ((host->variant->explicit_mclk_control) &&
>> >+	    (ios->clock != host->clock_cache)) {
> Please explain what use these parens have (or just get rid of them as
> they're completely unnecessary - they do nothing for readability.)
I agree, will fix this in next version, It was a left over from my 
previous patches which had one more variable in that first check.

Thanks,
srini

Re: [PATCH v5 02/13] mmc: mmci: convert register bits to use BIT() macro.

[Srinivas Kandagatla]

Thanks Russell,

On 31/05/14 13:35, Russell King - ARM Linux wrote:
> because allegedly it makes it more "readable".  I don't see much benefit
> to this patch.
Ok, I will drop this patch in next version.

thanks,
srini