[PATCH 0/5] mtk-sd enhancement to support MT7621

[PATCH 0/5] mtk-sd enhancement to support MT7621

[NeilBrown]

The MT7621 MIPS-based SOC contains an sdhci unit that is
much the same as the units supported by mtk-sd.c.

These patches enhance the driver so that I can use it on my MT7621
board (gnubee.org).

Some thoughts:
- I wonder if voltage-ranges should be a standard option, processed
    by mmc_of_parse(), rather than requiring mmc_of_parse_voltage()
    to be called as well?

- the "compatible" name "ralink,mt7620-sdhci" doesn't fit the pattern
  of other names.  It is a name I found in openwrt - I was previously
  using a driver from there.  I have no objection to changing it,
  but I have no way to determine what the "correct" name it.

- I have tested the card-detect logic but not the write-protect, as
  that doesn't seem to be wired on this board.

- My SOC doesn't have software-controlled clocks (that I can find).
  To get the clocks that the driver requires, I define a "fixed-clock"
  with the appropriate frequency and use that for both  "source" and
  "hclk".  Many these clocks should be optional - at least hclk ??

- I don't need to reconfigure the pins for "uhs" so I just use the
  same pinctrl setting for "default" and for "state_uhs".  Maybe
  "state_uhs" should be optional?


For reference, excerpts from my dts file are below.

Thanks,
NeilBrown


       mmc_clock: mmc_clock@0 {
               #clock-cells = <0>;
               compatible = "fixed-clock";
               clock-frequency = <48000000>;
       };

and

       sdhci: sdhci@1E130000 {
               status = "disabled";

               compatible = "ralink,mt7620-sdhci";
               reg = <0x1E130000 0x4000>;

               bus-width = <4>;
               max-frequency = <48000000>;
               cap-sd-highspeed;
               cap-mmc-highspeed;
               voltage-ranges = <2800 3300>;

               pinctrl-names = "default", "state_uhs";
               pinctrl-0 = <&sdhci_pins>;
               pinctrl-1 = <&sdhci_pins>;
               clocks = <&mmc_clock &mmc_clock>;
               clock-names = "source", "hclk";

               interrupt-parent = <&gic>;
               interrupts = <GIC_SHARED 20 IRQ_TYPE_LEVEL_HIGH>;
       };

---

NeilBrown (5):
      mmc: mtk-sd: support "voltage-ranges" setting.
      mmc: mtk-sd: don't hard-code interrupt trigger type
      mmc: mtk-sd: add support for config found in mt7620 family SOCs.
      mmc: mtk-sd: enable internal card-detect logic.
      mmc: mtk-sd: enable internal write-protect logic.


 Documentation/devicetree/bindings/mmc/mtk-sd.txt |    7 +
 drivers/mmc/host/mtk-sd.c                        |  105 +++++++++++++++++++++-
 2 files changed, 104 insertions(+), 8 deletions(-)

--
Signature

[PATCH 1/5] mmc: mtk-sd: support "voltage-ranges" setting.

[NeilBrown]

If the mtk-sd silicon is used in a context where there is no explicit
regulator, it is not currently possible to specify the voltage
ranges.  This is true for the MT7621 MIPS Soc.

So add a called to mmc_of_parse_voltage() so that voltage-ranges can
be given.

Signed-off-by: NeilBrown <neil@brown.name>
---
 Documentation/devicetree/bindings/mmc/mtk-sd.txt |    6 ++++--
 drivers/mmc/host/mtk-sd.c                        |    3 +++
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/mmc/mtk-sd.txt b/Documentation/devicetree/bindings/mmc/mtk-sd.txt
index f5bcda3980cc..ed61cd5a5b8f 100644
--- a/Documentation/devicetree/bindings/mmc/mtk-sd.txt
+++ b/Documentation/devicetree/bindings/mmc/mtk-sd.txt
@@ -27,10 +27,12 @@ Required properties:
 - pinctrl-names: should be "default", "state_uhs"
 - pinctrl-0: should contain default/high speed pin ctrl
 - pinctrl-1: should contain uhs mode pin ctrl
-- vmmc-supply: power to the Core
-- vqmmc-supply: power to the IO
 
 Optional properties:
+- vmmc-supply: power to the Core
+- vqmmc-supply: power to the IO
+- voltage-ranges: if vmmc-supply not present, this can specify pairs
+	of millivolt numbers to describe available ranged.
 - assigned-clocks: PLL of the source clock
 - assigned-clock-parents: parent of source clock, used for HS400 mode to get 400Mhz source clock
 - hs400-ds-delay: HS400 DS delay setting
diff --git a/drivers/mmc/host/mtk-sd.c b/drivers/mmc/host/mtk-sd.c
index 0798f0ba6d34..4492a4465c0e 100644
--- a/drivers/mmc/host/mtk-sd.c
+++ b/drivers/mmc/host/mtk-sd.c
@@ -2125,6 +2125,9 @@ static int msdc_drv_probe(struct platform_device *pdev)
 	ret = mmc_of_parse(mmc);
 	if (ret)
 		goto host_free;
+	ret = mmc_of_parse_voltage(pdev->dev.of_node, &mmc->ocr_avail);
+	if (ret < 0)
+		goto host_free;
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	host->base = devm_ioremap_resource(&pdev->dev, res);

[PATCH 2/5] mmc: mtk-sd: don't hard-code interrupt trigger type

[NeilBrown]

When using devicetree for configuration, interrupt trigger type
should be described in the dts file, not hard-coded in the C code.

The mtk-sd silicon in the mt7621 soc uses an active-high interrupt
and so cannot be used with the current code.

So remove the trigger and leave it to be set from devicetree.

Signed-off-by: NeilBrown <neil@brown.name>
---
 drivers/mmc/host/mtk-sd.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/mmc/host/mtk-sd.c b/drivers/mmc/host/mtk-sd.c
index 4492a4465c0e..14e048239143 100644
--- a/drivers/mmc/host/mtk-sd.c
+++ b/drivers/mmc/host/mtk-sd.c
@@ -2243,7 +2243,7 @@ static int msdc_drv_probe(struct platform_device *pdev)
 	msdc_init_hw(host);
 
 	ret = devm_request_irq(&pdev->dev, host->irq, msdc_irq,
-		IRQF_TRIGGER_LOW | IRQF_ONESHOT, pdev->name, host);
+			       0, pdev->name, host);
 	if (ret)
 		goto release;
 

[PATCH 3/5] mmc: mtk-sd: add support for config found in mt7620 family SOCs.

[NeilBrown]

mt7620 family MIPS SOCs contain the mtk-sd silicon.
Add support for this.

Signed-off-by: NeilBrown <neil@brown.name>

# Conflicts:
#	drivers/mmc/host/mtk-sd.c
---
 Documentation/devicetree/bindings/mmc/mtk-sd.txt |    1 +
 drivers/mmc/host/mtk-sd.c                        |   12 ++++++++++++
 2 files changed, 13 insertions(+)

diff --git a/Documentation/devicetree/bindings/mmc/mtk-sd.txt b/Documentation/devicetree/bindings/mmc/mtk-sd.txt
index ed61cd5a5b8f..b6daa9773b25 100644
--- a/Documentation/devicetree/bindings/mmc/mtk-sd.txt
+++ b/Documentation/devicetree/bindings/mmc/mtk-sd.txt
@@ -15,6 +15,7 @@ Required properties:
 	"mediatek,mt2712-mmc": for mmc host ip compatible with mt2712
 	"mediatek,mt7622-mmc": for MT7622 SoC
 	"mediatek,mt7623-mmc", "mediatek,mt2701-mmc": for MT7623 SoC
+	"ralink,mt7620-sdhci", for MT7621 SoC (and others)
 
 - reg: physical base address of the controller and length
 - interrupts: Should contain MSDC interrupt number
diff --git a/drivers/mmc/host/mtk-sd.c b/drivers/mmc/host/mtk-sd.c
index 14e048239143..d379f2ece305 100644
--- a/drivers/mmc/host/mtk-sd.c
+++ b/drivers/mmc/host/mtk-sd.c
@@ -517,6 +517,17 @@ static const struct mtk_mmc_compatible mt8516_compat = {
 	.stop_clk_fix = true,
 };
 
+static const struct mtk_mmc_compatible mt7620_compat = {
+	.clk_div_bits = 8,
+	.hs400_tune = false,
+	.pad_tune_reg = MSDC_PAD_TUNE,
+	.async_fifo = false,
+	.data_tune = false,
+	.busy_check = false,
+	.stop_clk_fix = false,
+	.enhance_rx = false,
+};
+
 static const struct of_device_id msdc_of_ids[] = {
 	{ .compatible = "mediatek,mt8135-mmc", .data = &mt8135_compat},
 	{ .compatible = "mediatek,mt8173-mmc", .data = &mt8173_compat},
@@ -525,6 +536,7 @@ static const struct of_device_id msdc_of_ids[] = {
 	{ .compatible = "mediatek,mt2712-mmc", .data = &mt2712_compat},
 	{ .compatible = "mediatek,mt7622-mmc", .data = &mt7622_compat},
 	{ .compatible = "mediatek,mt8516-mmc", .data = &mt8516_compat},
+	{ .compatible = "ralink,mt7620-sdhci", .data = &mt7620_compat},
 	{}
 };
 MODULE_DEVICE_TABLE(of, msdc_of_ids);

[PATCH 4/5] mmc: mtk-sd: enable internal card-detect logic.

[NeilBrown]

The mtk-sd silicon has integrated card-detect logic that is
enabled, at least, on the MT7621 as used in the GNUBEE NAS.

If the sdhci isn't marked non-removable and doesn't have a
cd-gpio configured, assume the internal cd logic should be used.

Signed-off-by: NeilBrown <neil@brown.name>
---
 drivers/mmc/host/mtk-sd.c |   58 ++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 54 insertions(+), 4 deletions(-)

diff --git a/drivers/mmc/host/mtk-sd.c b/drivers/mmc/host/mtk-sd.c
index d379f2ece305..341cf5f03429 100644
--- a/drivers/mmc/host/mtk-sd.c
+++ b/drivers/mmc/host/mtk-sd.c
@@ -300,6 +300,8 @@
 #define CMD_TIMEOUT         (HZ/10 * 5)	/* 100ms x5 */
 #define DAT_TIMEOUT         (HZ    * 5)	/* 1000ms x5 */
 
+#define DEFAULT_DEBOUNCE	(8)	/* 8 cycles CD debounce */
+
 #define PAD_DELAY_MAX	32 /* PAD delay cells */
 /*--------------------------------------------------------------------------*/
 /* Descriptor Structure                                                     */
@@ -430,6 +432,7 @@ struct msdc_host {
 	bool hs400_cmd_resp_sel_rising;
 				 /* cmd response sample selection for HS400 */
 	bool hs400_mode;	/* current eMMC will run at hs400 mode */
+	bool internal_cd;	/* Use internal card-detect logic */
 	struct msdc_save_para save_para; /* used when gate HCLK */
 	struct msdc_tune_para def_tune_para; /* default tune setting */
 	struct msdc_tune_para saved_tune_para; /* tune result of CMD21/CMD19 */
@@ -1430,6 +1433,11 @@ static irqreturn_t msdc_irq(int irq, void *dev_id)
 			sdio_signal_irq(host->mmc);
 		}
 
+		if ((events & event_mask) & MSDC_INT_CDSC) {
+			mmc_detect_change(host->mmc, msecs_to_jiffies(20));
+			events &= ~MSDC_INT_CDSC;
+		}
+
 		if (!(events & (event_mask & ~MSDC_INT_SDIOIRQ)))
 			break;
 
@@ -1463,14 +1471,24 @@ static void msdc_init_hw(struct msdc_host *host)
 	/* Reset */
 	msdc_reset_hw(host);
 
-	/* Disable card detection */
-	sdr_clr_bits(host->base + MSDC_PS, MSDC_PS_CDEN);
-
 	/* Disable and clear all interrupts */
 	writel(0, host->base + MSDC_INTEN);
 	val = readl(host->base + MSDC_INT);
 	writel(val, host->base + MSDC_INT);
 
+	/* Configure card detection */
+	if (host->internal_cd) {
+		sdr_set_field(host->base + MSDC_PS, MSDC_PS_CDDEBOUNCE,
+			      DEFAULT_DEBOUNCE);
+		sdr_set_bits(host->base + MSDC_PS, MSDC_PS_CDEN);
+		sdr_set_bits(host->base + MSDC_INTEN, MSDC_INTEN_CDSC);
+		sdr_set_bits(host->base + SDC_CFG, SDC_CFG_INSWKUP);
+	} else {
+		sdr_clr_bits(host->base + SDC_CFG, SDC_CFG_INSWKUP);
+		sdr_clr_bits(host->base + MSDC_PS, MSDC_PS_CDEN);
+		sdr_clr_bits(host->base + MSDC_INTEN, MSDC_INTEN_CDSC);
+	}
+
 	if (host->top_base) {
 		writel(0, host->top_base + EMMC_TOP_CONTROL);
 		writel(0, host->top_base + EMMC_TOP_CMD);
@@ -1580,6 +1598,11 @@ static void msdc_init_hw(struct msdc_host *host)
 static void msdc_deinit_hw(struct msdc_host *host)
 {
 	u32 val;
+
+	/* Disabled card-detect */
+	sdr_clr_bits(host->base + MSDC_PS, MSDC_PS_CDEN);
+	sdr_clr_bits(host->base + SDC_CFG, SDC_CFG_INSWKUP);
+
 	/* Disable and clear all interrupts */
 	writel(0, host->base + MSDC_INTEN);
 
@@ -2078,13 +2101,31 @@ static void msdc_ack_sdio_irq(struct mmc_host *mmc)
 	__msdc_enable_sdio_irq(mmc, 1);
 }
 
+static int msdc_get_cd(struct mmc_host *mmc)
+{
+	struct msdc_host *host = mmc_priv(mmc);
+	int val;
+
+	if (mmc->caps & MMC_CAP_NONREMOVABLE)
+		return 1;
+
+	if (!host->internal_cd)
+		return mmc_gpio_get_cd(mmc);
+
+	val = readl(host->base + MSDC_PS) & MSDC_PS_CDSTS;
+	if (mmc->caps2 & MMC_CAP2_CD_ACTIVE_HIGH)
+		return !!val;
+	else
+		return !val;
+}
+
 static const struct mmc_host_ops mt_msdc_ops = {
 	.post_req = msdc_post_req,
 	.pre_req = msdc_pre_req,
 	.request = msdc_ops_request,
 	.set_ios = msdc_ops_set_ios,
 	.get_ro = mmc_gpio_get_ro,
-	.get_cd = mmc_gpio_get_cd,
+	.get_cd = msdc_get_cd,
 	.enable_sdio_irq = msdc_enable_sdio_irq,
 	.ack_sdio_irq = msdc_ack_sdio_irq,
 	.start_signal_voltage_switch = msdc_ops_switch_volt,
@@ -2206,6 +2247,15 @@ static int msdc_drv_probe(struct platform_device *pdev)
 		goto host_free;
 	}
 
+	if (!(mmc->caps & MMC_CAP_NONREMOVABLE) &&
+	    !mmc_can_gpio_cd(mmc)) {
+		/*
+		 * Is removable but no GPIO declared, so
+		 * use internal functionality.
+		 */
+		host->internal_cd = true;
+	}
+
 	msdc_of_property_parse(pdev, host);
 
 	host->dev = &pdev->dev;

[PATCH 5/5] mmc: mtk-sd: enable internal write-protect logic.

[NeilBrown]

The mtk-sd silicon has integrated write-protect detection logic.

If the sdhci isn't marked no-write-protect and doesn't have a
ro-gpio configured, assume the internal wp logic should be used.

Signed-off-by: NeilBrown <neil@brown.name>
---
 drivers/mmc/host/mtk-sd.c |   30 +++++++++++++++++++++++++++++-
 1 file changed, 29 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/host/mtk-sd.c b/drivers/mmc/host/mtk-sd.c
index 341cf5f03429..d63d6b62f49a 100644
--- a/drivers/mmc/host/mtk-sd.c
+++ b/drivers/mmc/host/mtk-sd.c
@@ -433,6 +433,7 @@ struct msdc_host {
 				 /* cmd response sample selection for HS400 */
 	bool hs400_mode;	/* current eMMC will run at hs400 mode */
 	bool internal_cd;	/* Use internal card-detect logic */
+	bool internal_ro;	/* Use internal write-protect logic */
 	struct msdc_save_para save_para; /* used when gate HCLK */
 	struct msdc_tune_para def_tune_para; /* default tune setting */
 	struct msdc_tune_para saved_tune_para; /* tune result of CMD21/CMD19 */
@@ -2119,12 +2120,30 @@ static int msdc_get_cd(struct mmc_host *mmc)
 		return !val;
 }
 
+static int msdc_get_ro(struct mmc_host *mmc)
+{
+	struct msdc_host *host = mmc_priv(mmc);
+	int val;
+
+	if (mmc->caps2 & MMC_CAP2_NO_WRITE_PROTECT)
+		return 0;
+
+	if (!host->internal_ro)
+		return mmc_gpio_get_ro(mmc);
+
+	val = readl(host->base + MSDC_PS) & MSDC_PS_WP;
+	if (mmc->caps2 & MMC_CAP2_RO_ACTIVE_HIGH)
+		return !!val;
+	else
+		return !val;
+}
+
 static const struct mmc_host_ops mt_msdc_ops = {
 	.post_req = msdc_post_req,
 	.pre_req = msdc_pre_req,
 	.request = msdc_ops_request,
 	.set_ios = msdc_ops_set_ios,
-	.get_ro = mmc_gpio_get_ro,
+	.get_ro = msdc_get_ro,
 	.get_cd = msdc_get_cd,
 	.enable_sdio_irq = msdc_enable_sdio_irq,
 	.ack_sdio_irq = msdc_ack_sdio_irq,
@@ -2256,6 +2275,15 @@ static int msdc_drv_probe(struct platform_device *pdev)
 		host->internal_cd = true;
 	}
 
+	if (!(mmc->caps2 & MMC_CAP2_NO_WRITE_PROTECT) &&
+	    !mmc_can_gpio_ro(mmc)) {
+		/*
+		 * Has write-protect but no GPIO declared, so
+		 * use internal functionality.
+		 */
+		host->internal_ro = true;
+	}
+
 	msdc_of_property_parse(pdev, host);
 
 	host->dev = &pdev->dev;

Re: [PATCH 2/5] mmc: mtk-sd: don't hard-code interrupt trigger type

[Chaotian Jing]

On Tue, 2019-04-16 at 14:47 +1000, NeilBrown wrote:
> When using devicetree for configuration, interrupt trigger type
> should be described in the dts file, not hard-coded in the C code.
> 
> The mtk-sd silicon in the mt7621 soc uses an active-high interrupt
> and so cannot be used with the current code.
> 
> So remove the trigger and leave it to be set from devicetree.
> 
> Signed-off-by: NeilBrown <neil@brown.name>
> ---
>  drivers/mmc/host/mtk-sd.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/mmc/host/mtk-sd.c b/drivers/mmc/host/mtk-sd.c
> index 4492a4465c0e..14e048239143 100644
> --- a/drivers/mmc/host/mtk-sd.c
> +++ b/drivers/mmc/host/mtk-sd.c
> @@ -2243,7 +2243,7 @@ static int msdc_drv_probe(struct platform_device *pdev)
>  	msdc_init_hw(host);
>  
>  	ret = devm_request_irq(&pdev->dev, host->irq, msdc_irq,
> -		IRQF_TRIGGER_LOW | IRQF_ONESHOT, pdev->name, host);
> +
change it to IRQF_TRIGGER_NONE | IRQF_ONESHOT
> 			       0, pdev->name, host);
>  	if (ret)
>  		goto release;
>  
> 
> 

Re: [PATCH 2/5] mmc: mtk-sd: don't hard-code interrupt trigger type

[NeilBrown]

[-- Attachment #1: Type: text/plain, Size: 1320 bytes --]

On Tue, Apr 16 2019, Chaotian Jing wrote:

> On Tue, 2019-04-16 at 14:47 +1000, NeilBrown wrote:
>> When using devicetree for configuration, interrupt trigger type
>> should be described in the dts file, not hard-coded in the C code.
>> 
>> The mtk-sd silicon in the mt7621 soc uses an active-high interrupt
>> and so cannot be used with the current code.
>> 
>> So remove the trigger and leave it to be set from devicetree.
>> 
>> Signed-off-by: NeilBrown <neil@brown.name>
>> ---
>>  drivers/mmc/host/mtk-sd.c |    2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>> 
>> diff --git a/drivers/mmc/host/mtk-sd.c b/drivers/mmc/host/mtk-sd.c
>> index 4492a4465c0e..14e048239143 100644
>> --- a/drivers/mmc/host/mtk-sd.c
>> +++ b/drivers/mmc/host/mtk-sd.c
>> @@ -2243,7 +2243,7 @@ static int msdc_drv_probe(struct platform_device *pdev)
>>  	msdc_init_hw(host);
>>  
>>  	ret = devm_request_irq(&pdev->dev, host->irq, msdc_irq,
>> -		IRQF_TRIGGER_LOW | IRQF_ONESHOT, pdev->name, host);
>> +
> change it to IRQF_TRIGGER_NONE | IRQF_ONESHOT

Why do we need IRQF_ONESHOT.  That is for threaded interrupted
handlers...
msdc_irq() clears the interrupts, so ONESHOT isn't needed.

???

NeilBrown


>> 			       0, pdev->name, host);
>>  	if (ret)
>>  		goto release;
>>  
>> 
>> 

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 832 bytes --]

Re: [PATCH 2/5] mmc: mtk-sd: don't hard-code interrupt trigger type

[Chaotian Jing]

On Wed, 2019-04-17 at 08:12 +1000, NeilBrown wrote:
> On Tue, Apr 16 2019, Chaotian Jing wrote:
> 
> > On Tue, 2019-04-16 at 14:47 +1000, NeilBrown wrote:
> >> When using devicetree for configuration, interrupt trigger type
> >> should be described in the dts file, not hard-coded in the C code.
> >> 
> >> The mtk-sd silicon in the mt7621 soc uses an active-high interrupt
> >> and so cannot be used with the current code.
> >> 
> >> So remove the trigger and leave it to be set from devicetree.
> >> 
> >> Signed-off-by: NeilBrown <neil@brown.name>
> >> ---
> >>  drivers/mmc/host/mtk-sd.c |    2 +-
> >>  1 file changed, 1 insertion(+), 1 deletion(-)
> >> 
> >> diff --git a/drivers/mmc/host/mtk-sd.c b/drivers/mmc/host/mtk-sd.c
> >> index 4492a4465c0e..14e048239143 100644
> >> --- a/drivers/mmc/host/mtk-sd.c
> >> +++ b/drivers/mmc/host/mtk-sd.c
> >> @@ -2243,7 +2243,7 @@ static int msdc_drv_probe(struct platform_device *pdev)
> >>  	msdc_init_hw(host);
> >>  
> >>  	ret = devm_request_irq(&pdev->dev, host->irq, msdc_irq,
> >> -		IRQF_TRIGGER_LOW | IRQF_ONESHOT, pdev->name, host);
> >> +
> > change it to IRQF_TRIGGER_NONE | IRQF_ONESHOT
> 
> Why do we need IRQF_ONESHOT.  That is for threaded interrupted
> handlers...
> msdc_irq() clears the interrupts, so ONESHOT isn't needed.
> 
> ???
> 
> NeilBrown
> 
> 
I just want to change it to IRQF_TRIGGER_NONE, Since IRQF_TRIGGER_NONE
is defined as 0, it's ok to use 0 instead of it.
> >> 			       0, pdev->name, host);
> >>  	if (ret)
> >>  		goto release;
> >>  
> >> 
> >> 

Re: [PATCH 4/5] mmc: mtk-sd: enable internal card-detect logic.

[Chaotian Jing]

On Tue, 2019-04-16 at 14:47 +1000, NeilBrown wrote:
> The mtk-sd silicon has integrated card-detect logic that is
> enabled, at least, on the MT7621 as used in the GNUBEE NAS.
> 
> If the sdhci isn't marked non-removable and doesn't have a
> cd-gpio configured, assume the internal cd logic should be used.
> 
> Signed-off-by: NeilBrown <neil@brown.name>
> ---
>  drivers/mmc/host/mtk-sd.c |   58 ++++++++++++++++++++++++++++++++++++++++++---
>  1 file changed, 54 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/mmc/host/mtk-sd.c b/drivers/mmc/host/mtk-sd.c
> index d379f2ece305..341cf5f03429 100644
> --- a/drivers/mmc/host/mtk-sd.c
> +++ b/drivers/mmc/host/mtk-sd.c
> @@ -300,6 +300,8 @@
>  #define CMD_TIMEOUT         (HZ/10 * 5)	/* 100ms x5 */
>  #define DAT_TIMEOUT         (HZ    * 5)	/* 1000ms x5 */
>  
> +#define DEFAULT_DEBOUNCE	(8)	/* 8 cycles CD debounce */
> +
>  #define PAD_DELAY_MAX	32 /* PAD delay cells */
>  /*--------------------------------------------------------------------------*/
>  /* Descriptor Structure                                                     */
> @@ -430,6 +432,7 @@ struct msdc_host {
>  	bool hs400_cmd_resp_sel_rising;
>  				 /* cmd response sample selection for HS400 */
>  	bool hs400_mode;	/* current eMMC will run at hs400 mode */
> +	bool internal_cd;	/* Use internal card-detect logic */
>  	struct msdc_save_para save_para; /* used when gate HCLK */
>  	struct msdc_tune_para def_tune_para; /* default tune setting */
>  	struct msdc_tune_para saved_tune_para; /* tune result of CMD21/CMD19 */
> @@ -1430,6 +1433,11 @@ static irqreturn_t msdc_irq(int irq, void *dev_id)
>  			sdio_signal_irq(host->mmc);
>  		}
>  
> +		if ((events & event_mask) & MSDC_INT_CDSC) {
> +			mmc_detect_change(host->mmc, msecs_to_jiffies(20));
> +			events &= ~MSDC_INT_CDSC;
> +		}
> +
>  		if (!(events & (event_mask & ~MSDC_INT_SDIOIRQ)))
>  			break;
>  
> @@ -1463,14 +1471,24 @@ static void msdc_init_hw(struct msdc_host *host)
>  	/* Reset */
>  	msdc_reset_hw(host);
>  
> -	/* Disable card detection */
> -	sdr_clr_bits(host->base + MSDC_PS, MSDC_PS_CDEN);
> -
>  	/* Disable and clear all interrupts */
>  	writel(0, host->base + MSDC_INTEN);
>  	val = readl(host->base + MSDC_INT);
>  	writel(val, host->base + MSDC_INT);
>  
> +	/* Configure card detection */
> +	if (host->internal_cd) {
> +		sdr_set_field(host->base + MSDC_PS, MSDC_PS_CDDEBOUNCE,
> +			      DEFAULT_DEBOUNCE);
> +		sdr_set_bits(host->base + MSDC_PS, MSDC_PS_CDEN);
> +		sdr_set_bits(host->base + MSDC_INTEN, MSDC_INTEN_CDSC);
> +		sdr_set_bits(host->base + SDC_CFG, SDC_CFG_INSWKUP);
> +	} else {
> +		sdr_clr_bits(host->base + SDC_CFG, SDC_CFG_INSWKUP);
> +		sdr_clr_bits(host->base + MSDC_PS, MSDC_PS_CDEN);
> +		sdr_clr_bits(host->base + MSDC_INTEN, MSDC_INTEN_CDSC);
> +	}
> +
>  	if (host->top_base) {
>  		writel(0, host->top_base + EMMC_TOP_CONTROL);
>  		writel(0, host->top_base + EMMC_TOP_CMD);
> @@ -1580,6 +1598,11 @@ static void msdc_init_hw(struct msdc_host *host)
>  static void msdc_deinit_hw(struct msdc_host *host)
>  {
>  	u32 val;
> +
> +	/* Disabled card-detect */
> +	sdr_clr_bits(host->base + MSDC_PS, MSDC_PS_CDEN);
> +	sdr_clr_bits(host->base + SDC_CFG, SDC_CFG_INSWKUP);
> +
>  	/* Disable and clear all interrupts */
>  	writel(0, host->base + MSDC_INTEN);
>  
> @@ -2078,13 +2101,31 @@ static void msdc_ack_sdio_irq(struct mmc_host *mmc)
>  	__msdc_enable_sdio_irq(mmc, 1);
>  }
>  
> +static int msdc_get_cd(struct mmc_host *mmc)
> +{
> +	struct msdc_host *host = mmc_priv(mmc);
> +	int val;
> +
> +	if (mmc->caps & MMC_CAP_NONREMOVABLE)
> +		return 1;
> +
> +	if (!host->internal_cd)
> +		return mmc_gpio_get_cd(mmc);
> +
> +	val = readl(host->base + MSDC_PS) & MSDC_PS_CDSTS;
> +	if (mmc->caps2 & MMC_CAP2_CD_ACTIVE_HIGH)
> +		return !!val;
> +	else
> +		return !val;
> +}
> +
>  static const struct mmc_host_ops mt_msdc_ops = {
>  	.post_req = msdc_post_req,
>  	.pre_req = msdc_pre_req,
>  	.request = msdc_ops_request,
>  	.set_ios = msdc_ops_set_ios,
>  	.get_ro = mmc_gpio_get_ro,
> -	.get_cd = mmc_gpio_get_cd,
> +	.get_cd = msdc_get_cd,
>  	.enable_sdio_irq = msdc_enable_sdio_irq,
>  	.ack_sdio_irq = msdc_ack_sdio_irq,
>  	.start_signal_voltage_switch = msdc_ops_switch_volt,
> @@ -2206,6 +2247,15 @@ static int msdc_drv_probe(struct platform_device *pdev)
>  		goto host_free;
>  	}
>  
> +	if (!(mmc->caps & MMC_CAP_NONREMOVABLE) &&
> +	    !mmc_can_gpio_cd(mmc)) {

Should not do this assume!
better to add "mediatek,internal-cd" in your DTS, then no impact to
other Soc.
> +		/*
> +		 * Is removable but no GPIO declared, so
> +		 * use internal functionality.
> +		 */
> +		host->internal_cd = true;
> +	}
> +
>  	msdc_of_property_parse(pdev, host);
>  
>  	host->dev = &pdev->dev;
> 
> 

Re: [PATCH 4/5] mmc: mtk-sd: enable internal card-detect logic.

[NeilBrown]

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On Thu, Apr 18 2019, Chaotian Jing wrote:

> On Tue, 2019-04-16 at 14:47 +1000, NeilBrown wrote:
>> The mtk-sd silicon has integrated card-detect logic that is
>> enabled, at least, on the MT7621 as used in the GNUBEE NAS.
>> 
>> If the sdhci isn't marked non-removable and doesn't have a
>> cd-gpio configured, assume the internal cd logic should be used.
>> 
>> Signed-off-by: NeilBrown <neil@brown.name>
...

>> @@ -2206,6 +2247,15 @@ static int msdc_drv_probe(struct platform_device *pdev)
>>  		goto host_free;
>>  	}
>>  
>> +	if (!(mmc->caps & MMC_CAP_NONREMOVABLE) &&
>> +	    !mmc_can_gpio_cd(mmc)) {
>
> Should not do this assume!
> better to add "mediatek,internal-cd" in your DTS, then no impact to
> other Soc.

(Sorry for the delay).

Documentation/devicetree/bindings/mmc/mmc.txt

says:
   If no property below is supplied, host native card detect is used.

So this assumption is *exactly* what the documentation said we should
do.

How about I limit this assumption to mt7621 using a flag in the
mtk_mmc_compatible structure?

Thanks,
NeilBrown

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