[PATCH 0/5] mmc: mmci: add get_datactrl_cfg callback

[PATCH 0/5] mmc: mmci: add get_datactrl_cfg callback

[Ludovic Barre]

From: Ludovic Barre <ludovic.barre@st.com>

This patch series adds get_datactrl_cfg callback in mmci_host_ops
to allow to get datactrl configuration specific at variant.

Ludovic Barre (5):
  mmc: mmci: add get_datactrl_cfg callback
  mmc: mmci: define get_dctrl_cfg for legacy variant
  mmc: mmci: qcom: define get_dctrl_cfg
  mmc: mmci: stm32: define get_dctrl_cfg
  mmc: mmci: replace blksz_datactrlXX by get_datactrl_cfg callback

 drivers/mmc/host/mmci.c             | 51 ++++++++++++++++++++++++-------------
 drivers/mmc/host/mmci.h             | 11 ++++----
 drivers/mmc/host/mmci_qcom_dml.c    |  8 ++++++
 drivers/mmc/host/mmci_stm32_sdmmc.c | 21 +++++++++++++++
 4 files changed, 68 insertions(+), 23 deletions(-)

-- 
2.7.4

[PATCH 1/5] mmc: mmci: add get_datactrl_cfg callback

[Ludovic Barre]

From: Ludovic Barre <ludovic.barre@st.com>

This patch adds get_datactrl_cfg callback in mmci_host_ops
to allow to get datactrl configuration specific at variant.

Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
---
 drivers/mmc/host/mmci.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/mmc/host/mmci.h b/drivers/mmc/host/mmci.h
index 14df810..6f28f71 100644
--- a/drivers/mmc/host/mmci.h
+++ b/drivers/mmc/host/mmci.h
@@ -362,6 +362,7 @@ struct mmci_host_ops {
 			 bool next);
 	void (*unprep_data)(struct mmci_host *host, struct mmc_data *data,
 			    int err);
+	u32 (*get_datactrl_cfg)(struct mmci_host *host);
 	void (*get_next_data)(struct mmci_host *host, struct mmc_data *data);
 	int (*dma_setup)(struct mmci_host *host);
 	void (*dma_release)(struct mmci_host *host);
-- 
2.7.4

[PATCH 2/5] mmc: mmci: define get_dctrl_cfg for legacy variant

[Ludovic Barre]

From: Ludovic Barre <ludovic.barre@st.com>

This patch defines get_dctrl_cfg callback for legacy variants
whatever DMA_ENGINE configuration.

Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
---
 drivers/mmc/host/mmci.c | 38 ++++++++++++++++++++++++++++++++------
 1 file changed, 32 insertions(+), 6 deletions(-)

diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index 387ff14..e1d3f42 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -47,11 +47,8 @@
 
 #define DRIVER_NAME "mmci-pl18x"
 
-#ifdef CONFIG_DMA_ENGINE
 void mmci_variant_init(struct mmci_host *host);
-#else
-static inline void mmci_variant_init(struct mmci_host *host) {}
-#endif
+void mmci_ux500v2_variant_init(struct mmci_host *host);
 
 #ifdef CONFIG_MMC_STM32_SDMMC
 void sdmmc_variant_init(struct mmci_host *host);
@@ -238,7 +235,7 @@ static struct variant_data variant_ux500v2 = {
 	.irq_pio_mask		= MCI_IRQ_PIO_MASK,
 	.start_err		= MCI_STARTBITERR,
 	.opendrain		= MCI_OD,
-	.init			= mmci_variant_init,
+	.init			= mmci_ux500v2_variant_init,
 };
 
 static struct variant_data variant_stm32 = {
@@ -624,6 +621,24 @@ static void mmci_init_sg(struct mmci_host *host, struct mmc_data *data)
 	sg_miter_start(&host->sg_miter, data->sg, data->sg_len, flags);
 }
 
+u32 mmci_get_dctrl_cfg(struct mmci_host *host)
+{
+	struct variant_data *variant = host->variant;
+	int blksz_bits;
+
+	blksz_bits = ffs(host->data->blksz) - 1;
+	BUG_ON(1 << blksz_bits != host->data->blksz);
+
+	return variant->datactrl_dpsm_enable | blksz_bits << 4;
+}
+
+u32 mmci_ux500v2_get_dctrl_cfg(struct mmci_host *host)
+{
+	struct variant_data *variant = host->variant;
+
+	return variant->datactrl_dpsm_enable | (host->data->blksz << 16);
+}
+
 /*
  * All the DMA operation mode stuff goes inside this ifdef.
  * This assumes that you have a generic DMA device interface,
@@ -952,6 +967,7 @@ void mmci_dmae_unprep_data(struct mmci_host *host,
 static struct mmci_host_ops mmci_variant_ops = {
 	.prep_data = mmci_dmae_prep_data,
 	.unprep_data = mmci_dmae_unprep_data,
+	.get_datactrl_cfg = mmci_get_dctrl_cfg,
 	.get_next_data = mmci_dmae_get_next_data,
 	.dma_setup = mmci_dmae_setup,
 	.dma_release = mmci_dmae_release,
@@ -959,12 +975,22 @@ static struct mmci_host_ops mmci_variant_ops = {
 	.dma_finalize = mmci_dmae_finalize,
 	.dma_error = mmci_dmae_error,
 };
+#else
+static struct mmci_host_ops mmci_variant_ops = {
+	.get_datactrl_cfg = mmci_get_dctrl_cfg,
+}
+#endif
 
 void mmci_variant_init(struct mmci_host *host)
 {
 	host->ops = &mmci_variant_ops;
 }
-#endif
+
+void mmci_ux500v2_variant_init(struct mmci_host *host)
+{
+	host->ops = &mmci_variant_ops;
+	host->ops->get_datactrl_cfg = mmci_ux500v2_get_dctrl_cfg;
+}
 
 static void mmci_pre_request(struct mmc_host *mmc, struct mmc_request *mrq)
 {
-- 
2.7.4

[PATCH 3/5] mmc: mmci: qcom: define get_dctrl_cfg

[Ludovic Barre]

From: Ludovic Barre <ludovic.barre@st.com>

This patch defines get_dctrl_cfg callback for qcom variant.
qcom variant has a specific block size definition.

Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
---
 drivers/mmc/host/mmci_qcom_dml.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/mmc/host/mmci_qcom_dml.c b/drivers/mmc/host/mmci_qcom_dml.c
index 25d0a75..d7b083d 100644
--- a/drivers/mmc/host/mmci_qcom_dml.c
+++ b/drivers/mmc/host/mmci_qcom_dml.c
@@ -183,9 +183,17 @@ static int qcom_dma_setup(struct mmci_host *host)
 	return 0;
 }
 
+u32 qcom_get_dctrl_cfg(struct mmci_host *host)
+{
+	struct variant_data *variant = host->variant;
+
+	return variant->datactrl_dpsm_enable | (host->data->blksz << 4);
+}
+
 static struct mmci_host_ops qcom_variant_ops = {
 	.prep_data = mmci_dmae_prep_data,
 	.unprep_data = mmci_dmae_unprep_data,
+	.get_datactrl_cfg = qcom_get_dctrl_cfg,
 	.get_next_data = mmci_dmae_get_next_data,
 	.dma_setup = qcom_dma_setup,
 	.dma_release = mmci_dmae_release,
-- 
2.7.4

[PATCH 4/5] mmc: mmci: stm32: define get_dctrl_cfg

[Ludovic Barre]

From: Ludovic Barre <ludovic.barre@st.com>

This patch defines get_dctrl_cfg callback for sdmmc variant.
sdmmc variant has specific stm32 transfer modes.
sdmmc data transfer mode selection could be:
-Block data transfer ending on block count.
-SDIO multibyte data transfer.
-MMC Stream data transfer (not used).
-Block data transfer ending with STOP_TRANSMISSION command.

Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
---
 drivers/mmc/host/mmci.h             |  5 +++++
 drivers/mmc/host/mmci_stm32_sdmmc.c | 21 +++++++++++++++++++++
 2 files changed, 26 insertions(+)

diff --git a/drivers/mmc/host/mmci.h b/drivers/mmc/host/mmci.h
index 6f28f71..eb5d99af 100644
--- a/drivers/mmc/host/mmci.h
+++ b/drivers/mmc/host/mmci.h
@@ -131,6 +131,11 @@
 /* Control register extensions in the Qualcomm versions */
 #define MCI_DPSM_QCOM_DATA_PEND	BIT(17)
 #define MCI_DPSM_QCOM_RX_DATA_PEND BIT(20)
+/* Control register extensions in STM32 versions */
+#define MCI_DPSM_STM32_MODE_BLOCK	(0 << 2)
+#define MCI_DPSM_STM32_MODE_SDIO	(1 << 2)
+#define MCI_DPSM_STM32_MODE_STREAM	(2 << 2)
+#define MCI_DPSM_STM32_MODE_BLOCK_STOP	(3 << 2)
 
 #define MMCIDATACNT		0x030
 #define MMCISTATUS		0x034
diff --git a/drivers/mmc/host/mmci_stm32_sdmmc.c b/drivers/mmc/host/mmci_stm32_sdmmc.c
index cfbfc6f..e7bf744 100644
--- a/drivers/mmc/host/mmci_stm32_sdmmc.c
+++ b/drivers/mmc/host/mmci_stm32_sdmmc.c
@@ -265,10 +265,31 @@ static void mmci_sdmmc_set_pwrreg(struct mmci_host *host, unsigned int pwr)
 	}
 }
 
+u32 sdmmc_get_dctrl_cfg(struct mmci_host *host)
+{
+	struct variant_data *variant = host->variant;
+	int blksz_bits;
+	u32 datactrl;
+
+	blksz_bits = ffs(host->data->blksz) - 1;
+	datactrl = variant->datactrl_dpsm_enable | blksz_bits << 4;
+
+	if (host->mmc->card && mmc_card_sdio(host->mmc->card) &&
+	    host->data->blocks == 1)
+		datactrl |= MCI_DPSM_STM32_MODE_SDIO;
+	else if (host->data->stop && !host->mrq->sbc)
+		datactrl |= MCI_DPSM_STM32_MODE_BLOCK_STOP;
+	else
+		datactrl |= MCI_DPSM_STM32_MODE_BLOCK;
+
+	return datactrl;
+}
+
 static struct mmci_host_ops sdmmc_variant_ops = {
 	.validate_data = sdmmc_idma_validate_data,
 	.prep_data = sdmmc_idma_prep_data,
 	.unprep_data = sdmmc_idma_unprep_data,
+	.get_datactrl_cfg = sdmmc_get_dctrl_cfg,
 	.dma_setup = sdmmc_idma_setup,
 	.dma_start = sdmmc_idma_start,
 	.dma_finalize = sdmmc_idma_finalize,
-- 
2.7.4

[PATCH 5/5] mmc: mmci: replace blksz_datactrlXX by get_datactrl_cfg callback

[Ludovic Barre]

From: Ludovic Barre <ludovic.barre@st.com>

This patch allows to get datactrl configuration specific
at variant. This introduce more flexibility on datactlr
value.

Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
---
 drivers/mmc/host/mmci.c | 13 +------------
 drivers/mmc/host/mmci.h |  5 -----
 2 files changed, 1 insertion(+), 17 deletions(-)

diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index e1d3f42..fe424ae 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -221,7 +221,6 @@ static struct variant_data variant_ux500v2 = {
 	.datactrl_mask_sdio	= MCI_DPSM_ST_SDIOEN,
 	.st_sdio		= true,
 	.st_clkdiv		= true,
-	.blksz_datactrl16	= true,
 	.pwrreg_powerup		= MCI_PWR_ON,
 	.f_max			= 100000000,
 	.signal_direction	= true,
@@ -296,7 +295,6 @@ static struct variant_data variant_qcom = {
 	.cmdreg_srsp_crc	= MCI_CPSM_RESPONSE,
 	.cmdreg_srsp		= MCI_CPSM_RESPONSE,
 	.data_cmd_enable	= MCI_CPSM_QCOM_DATCMD,
-	.blksz_datactrl4	= true,
 	.datalength_bits	= 24,
 	.datactrl_blocksz	= 11,
 	.datactrl_dpsm_enable	= MCI_DPSM_ENABLE,
@@ -1026,7 +1024,6 @@ static void mmci_start_data(struct mmci_host *host, struct mmc_data *data)
 	unsigned int datactrl, timeout, irqmask;
 	unsigned long long clks;
 	void __iomem *base;
-	int blksz_bits;
 
 	dev_dbg(mmc_dev(host->mmc), "blksz %04x blks %04x flags %08x\n",
 		data->blksz, data->blocks, data->flags);
@@ -1044,15 +1041,7 @@ static void mmci_start_data(struct mmci_host *host, struct mmc_data *data)
 	writel(timeout, base + MMCIDATATIMER);
 	writel(host->size, base + MMCIDATALENGTH);
 
-	blksz_bits = ffs(data->blksz) - 1;
-	BUG_ON(1 << blksz_bits != data->blksz);
-
-	if (variant->blksz_datactrl16)
-		datactrl = variant->datactrl_dpsm_enable | (data->blksz << 16);
-	else if (variant->blksz_datactrl4)
-		datactrl = variant->datactrl_dpsm_enable | (data->blksz << 4);
-	else
-		datactrl = variant->datactrl_dpsm_enable | blksz_bits << 4;
+	datactrl = host->ops->get_datactrl_cfg(host);
 
 	if (data->flags & MMC_DATA_READ)
 		datactrl |= MCI_DPSM_DIRECTION;
diff --git a/drivers/mmc/host/mmci.h b/drivers/mmc/host/mmci.h
index eb5d99af..fb5a83f 100644
--- a/drivers/mmc/host/mmci.h
+++ b/drivers/mmc/host/mmci.h
@@ -280,9 +280,6 @@ struct mmci_host;
  * @st_clkdiv: true if using a ST-specific clock divider algorithm
  * @stm32_clkdiv: true if using a STM32-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
  * @datactrl_mask_sdio: SDIO enable mask in datactrl register
  * @datactrl_blksz: block size in power of two
  * @datactrl_dpsm_enable: enable value for DPSM
@@ -336,8 +333,6 @@ struct variant_data {
 	u8			st_sdio:1;
 	u8			st_clkdiv:1;
 	u8			stm32_clkdiv:1;
-	u8			blksz_datactrl16:1;
-	u8			blksz_datactrl4:1;
 	u32			pwrreg_powerup;
 	u32			f_max;
 	u8			signal_direction:1;
-- 
2.7.4

Re: [PATCH 3/5] mmc: mmci: qcom: define get_dctrl_cfg

[Ulf Hansson]

On Mon, 4 Mar 2019 at 11:17, Ludovic Barre <ludovic.Barre@st.com> wrote:
>
> From: Ludovic Barre <ludovic.barre@st.com>
>
> This patch defines get_dctrl_cfg callback for qcom variant.
> qcom variant has a specific block size definition.
>
> Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
> ---
>  drivers/mmc/host/mmci_qcom_dml.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
>
> diff --git a/drivers/mmc/host/mmci_qcom_dml.c b/drivers/mmc/host/mmci_qcom_dml.c
> index 25d0a75..d7b083d 100644
> --- a/drivers/mmc/host/mmci_qcom_dml.c
> +++ b/drivers/mmc/host/mmci_qcom_dml.c
> @@ -183,9 +183,17 @@ static int qcom_dma_setup(struct mmci_host *host)
>         return 0;
>  }
>
> +u32 qcom_get_dctrl_cfg(struct mmci_host *host)

This can be static.

> +{
> +       struct variant_data *variant = host->variant;
> +
> +       return variant->datactrl_dpsm_enable | (host->data->blksz << 4);
> +}
> +
>  static struct mmci_host_ops qcom_variant_ops = {
>         .prep_data = mmci_dmae_prep_data,
>         .unprep_data = mmci_dmae_unprep_data,
> +       .get_datactrl_cfg = qcom_get_dctrl_cfg,
>         .get_next_data = mmci_dmae_get_next_data,
>         .dma_setup = qcom_dma_setup,
>         .dma_release = mmci_dmae_release,
> --
> 2.7.4
>

Kind regards
Uffe

Re: [PATCH 4/5] mmc: mmci: stm32: define get_dctrl_cfg

[Ulf Hansson]

On Mon, 4 Mar 2019 at 11:17, Ludovic Barre <ludovic.Barre@st.com> wrote:
>
> From: Ludovic Barre <ludovic.barre@st.com>
>
> This patch defines get_dctrl_cfg callback for sdmmc variant.
> sdmmc variant has specific stm32 transfer modes.
> sdmmc data transfer mode selection could be:
> -Block data transfer ending on block count.
> -SDIO multibyte data transfer.
> -MMC Stream data transfer (not used).
> -Block data transfer ending with STOP_TRANSMISSION command.
>
> Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
> ---
>  drivers/mmc/host/mmci.h             |  5 +++++
>  drivers/mmc/host/mmci_stm32_sdmmc.c | 21 +++++++++++++++++++++
>  2 files changed, 26 insertions(+)
>
> diff --git a/drivers/mmc/host/mmci.h b/drivers/mmc/host/mmci.h
> index 6f28f71..eb5d99af 100644
> --- a/drivers/mmc/host/mmci.h
> +++ b/drivers/mmc/host/mmci.h
> @@ -131,6 +131,11 @@
>  /* Control register extensions in the Qualcomm versions */
>  #define MCI_DPSM_QCOM_DATA_PEND        BIT(17)
>  #define MCI_DPSM_QCOM_RX_DATA_PEND BIT(20)
> +/* Control register extensions in STM32 versions */
> +#define MCI_DPSM_STM32_MODE_BLOCK      (0 << 2)
> +#define MCI_DPSM_STM32_MODE_SDIO       (1 << 2)
> +#define MCI_DPSM_STM32_MODE_STREAM     (2 << 2)
> +#define MCI_DPSM_STM32_MODE_BLOCK_STOP (3 << 2)
>
>  #define MMCIDATACNT            0x030
>  #define MMCISTATUS             0x034
> diff --git a/drivers/mmc/host/mmci_stm32_sdmmc.c b/drivers/mmc/host/mmci_stm32_sdmmc.c
> index cfbfc6f..e7bf744 100644
> --- a/drivers/mmc/host/mmci_stm32_sdmmc.c
> +++ b/drivers/mmc/host/mmci_stm32_sdmmc.c
> @@ -265,10 +265,31 @@ static void mmci_sdmmc_set_pwrreg(struct mmci_host *host, unsigned int pwr)
>         }
>  }
>
> +u32 sdmmc_get_dctrl_cfg(struct mmci_host *host)
> +{
> +       struct variant_data *variant = host->variant;
> +       int blksz_bits;
> +       u32 datactrl;
> +
> +       blksz_bits = ffs(host->data->blksz) - 1;
> +       datactrl = variant->datactrl_dpsm_enable | blksz_bits << 4;
> +
> +       if (host->mmc->card && mmc_card_sdio(host->mmc->card) &&
> +           host->data->blocks == 1)

These settings are not limited to deal with the block size bits.

Don't get me wrong, it seems reasonable to include them, but the
generic code in mmci_start_data() also have code to cope with SDIO. I
think we should start by splitting that up into a couple of
helper/library functions, and make the legacy variant to use them.
This should probably be done as a preparation to your series, so you
can build on top of that.

Does it make sense? If not, please tell and I can try to provide some
patch to show you what I mean.


> +               datactrl |= MCI_DPSM_STM32_MODE_SDIO;
> +       else if (host->data->stop && !host->mrq->sbc)
> +               datactrl |= MCI_DPSM_STM32_MODE_BLOCK_STOP;
> +       else
> +               datactrl |= MCI_DPSM_STM32_MODE_BLOCK;
> +
> +       return datactrl;
> +}
> +
>  static struct mmci_host_ops sdmmc_variant_ops = {
>         .validate_data = sdmmc_idma_validate_data,
>         .prep_data = sdmmc_idma_prep_data,
>         .unprep_data = sdmmc_idma_unprep_data,
> +       .get_datactrl_cfg = sdmmc_get_dctrl_cfg,
>         .dma_setup = sdmmc_idma_setup,
>         .dma_start = sdmmc_idma_start,
>         .dma_finalize = sdmmc_idma_finalize,
> --
> 2.7.4
>

Kind regards
Uffe

Re: [PATCH 4/5] mmc: mmci: stm32: define get_dctrl_cfg

[Ludovic BARRE]

On 3/6/19 2:31 PM, Ulf Hansson wrote:
> On Mon, 4 Mar 2019 at 11:17, Ludovic Barre <ludovic.Barre@st.com> wrote:
>>
>> From: Ludovic Barre <ludovic.barre@st.com>
>>
>> This patch defines get_dctrl_cfg callback for sdmmc variant.
>> sdmmc variant has specific stm32 transfer modes.
>> sdmmc data transfer mode selection could be:
>> -Block data transfer ending on block count.
>> -SDIO multibyte data transfer.
>> -MMC Stream data transfer (not used).
>> -Block data transfer ending with STOP_TRANSMISSION command.
>>
>> Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
>> ---
>>   drivers/mmc/host/mmci.h             |  5 +++++
>>   drivers/mmc/host/mmci_stm32_sdmmc.c | 21 +++++++++++++++++++++
>>   2 files changed, 26 insertions(+)
>>
>> diff --git a/drivers/mmc/host/mmci.h b/drivers/mmc/host/mmci.h
>> index 6f28f71..eb5d99af 100644
>> --- a/drivers/mmc/host/mmci.h
>> +++ b/drivers/mmc/host/mmci.h
>> @@ -131,6 +131,11 @@
>>   /* Control register extensions in the Qualcomm versions */
>>   #define MCI_DPSM_QCOM_DATA_PEND        BIT(17)
>>   #define MCI_DPSM_QCOM_RX_DATA_PEND BIT(20)
>> +/* Control register extensions in STM32 versions */
>> +#define MCI_DPSM_STM32_MODE_BLOCK      (0 << 2)
>> +#define MCI_DPSM_STM32_MODE_SDIO       (1 << 2)
>> +#define MCI_DPSM_STM32_MODE_STREAM     (2 << 2)
>> +#define MCI_DPSM_STM32_MODE_BLOCK_STOP (3 << 2)
>>
>>   #define MMCIDATACNT            0x030
>>   #define MMCISTATUS             0x034
>> diff --git a/drivers/mmc/host/mmci_stm32_sdmmc.c b/drivers/mmc/host/mmci_stm32_sdmmc.c
>> index cfbfc6f..e7bf744 100644
>> --- a/drivers/mmc/host/mmci_stm32_sdmmc.c
>> +++ b/drivers/mmc/host/mmci_stm32_sdmmc.c
>> @@ -265,10 +265,31 @@ static void mmci_sdmmc_set_pwrreg(struct mmci_host *host, unsigned int pwr)
>>          }
>>   }
>>
>> +u32 sdmmc_get_dctrl_cfg(struct mmci_host *host)
>> +{
>> +       struct variant_data *variant = host->variant;
>> +       int blksz_bits;
>> +       u32 datactrl;
>> +
>> +       blksz_bits = ffs(host->data->blksz) - 1;
>> +       datactrl = variant->datactrl_dpsm_enable | blksz_bits << 4;
>> +
>> +       if (host->mmc->card && mmc_card_sdio(host->mmc->card) &&
>> +           host->data->blocks == 1)
> 
> These settings are not limited to deal with the block size bits.
> 
> Don't get me wrong, it seems reasonable to include them, but the
> generic code in mmci_start_data() also have code to cope with SDIO. I
> think we should start by splitting that up into a couple of
> helper/library functions, and make the legacy variant to use them.
> This should probably be done as a preparation to your series, so you
> can build on top of that.

I think you wish helper functions for each group of datactrl feature,
like for dpsm direction|sdio|ios timming. Each variant call theses 
helpers to define its own datactrl value. it's possible, no problem.

In mmci_start_data will remain the part on clk_reg for sdio card
	if (host->mmc->card && mmc_card_sdio(host->mmc->card)) {
		u32 clk;

		/*
		 * The ST Micro variant for SDIO small write transfers
		 * needs to have clock H/W flow control disabled,
		 * otherwise the transfer will not start. The threshold
		 * depends on the rate of MCLK.
		 */
		if (variant->st_sdio && data->flags & MMC_DATA_WRITE &&
		    (host->size < 8 ||
		     (host->size <= 8 && host->mclk > 50000000)))
			clk = host->clk_reg & ~variant->clkreg_enable;
		else
			clk = host->clk_reg | variant->clkreg_enable;

		mmci_write_clkreg(host, clk);
	}

it's OK ?

> 
> Does it make sense? If not, please tell and I can try to provide some
> patch to show you what I mean.
> 
> 
>> +               datactrl |= MCI_DPSM_STM32_MODE_SDIO;
>> +       else if (host->data->stop && !host->mrq->sbc)
>> +               datactrl |= MCI_DPSM_STM32_MODE_BLOCK_STOP;
>> +       else
>> +               datactrl |= MCI_DPSM_STM32_MODE_BLOCK;
>> +
>> +       return datactrl;
>> +}
>> +
>>   static struct mmci_host_ops sdmmc_variant_ops = {
>>          .validate_data = sdmmc_idma_validate_data,
>>          .prep_data = sdmmc_idma_prep_data,
>>          .unprep_data = sdmmc_idma_unprep_data,
>> +       .get_datactrl_cfg = sdmmc_get_dctrl_cfg,
>>          .dma_setup = sdmmc_idma_setup,
>>          .dma_start = sdmmc_idma_start,
>>          .dma_finalize = sdmmc_idma_finalize,
>> --
>> 2.7.4
>>
> 
> Kind regards
> Uffe
>