[PATCH v3 2/5] mmc: sdhci-pxav3: enable usage of DAT3 pin as HW card detect
Marcin Wojtas
mw at semihalf.com
Thu Oct 15 09:25:43 PDT 2015
Marvell Armada 38x SDHCI controller enable using DAT3 pin as a hardware
card detection. According to the SD sdandard this signal can be used for
this purpose combined with a pull-down resistor, implying inverted (active
high) polarization of a card detect. MMC standard does not support this
feature and does not operate with such connectivity of DAT3.
When using DAT3-based detection Armada 38x SDIO IP expects its internal
clock to be always on, which had to be ensured by:
- Udating appropriate registers, each time controller is reset. On the
occasion of adding new register @0x104, register @0x100 name is modified
in order to the be aligned with Armada 38x documentation.
- Leaving the clock enabled despite power-down. For this purpose a wrapper
for sdhci_set_clock function is added.
- Disabling pm_runtime - during suspend both io_clock and controller's
bus power is switched off, hence it would prevent proper card detection.
In addition to the changes above this commit adds a new property to Armada
38x SDHCI node ('dat3-cd') with an according binding documentation update.
'sdhci_pxa' structure is also extended with dedicated flag for checking if
DAT3-based detection is in use.
Signed-off-by: Marcin Wojtas <mw at semihalf.com>
---
.../devicetree/bindings/mmc/sdhci-pxa.txt | 5 ++
drivers/mmc/host/sdhci-pxav3.c | 100 +++++++++++++++++----
2 files changed, 87 insertions(+), 18 deletions(-)
diff --git a/Documentation/devicetree/bindings/mmc/sdhci-pxa.txt b/Documentation/devicetree/bindings/mmc/sdhci-pxa.txt
index 3d1b449..ffd6b14 100644
--- a/Documentation/devicetree/bindings/mmc/sdhci-pxa.txt
+++ b/Documentation/devicetree/bindings/mmc/sdhci-pxa.txt
@@ -23,6 +23,11 @@ Required properties:
Optional properties:
- mrvl,clk-delay-cycles: Specify a number of cycles to delay for tuning.
+- dat3-cd: use DAT3 pin as hardware card detect - option available for
+ "marvell,armada-380-sdhci" only. The detection is supposed to work with
+ active high polarity, which implies usage of "cd-inverted" property.
+ Note that according to the specifications DAT3-based card detection can be
+ used with SD cards only. MMC standard doesn't support this feature.
Example:
diff --git a/drivers/mmc/host/sdhci-pxav3.c b/drivers/mmc/host/sdhci-pxav3.c
index 54a253c0..d813233 100644
--- a/drivers/mmc/host/sdhci-pxav3.c
+++ b/drivers/mmc/host/sdhci-pxav3.c
@@ -46,10 +46,14 @@
#define SDCLK_DELAY_SHIFT 9
#define SDCLK_DELAY_MASK 0x1f
-#define SD_CFG_FIFO_PARAM 0x100
+#define SD_EXTRA_PARAM_REG 0x100
#define SDCFG_GEN_PAD_CLK_ON (1<<6)
#define SDCFG_GEN_PAD_CLK_CNT_MASK 0xFF
#define SDCFG_GEN_PAD_CLK_CNT_SHIFT 24
+#define SD_FIFO_PARAM_REG 0x104
+#define SD_USE_DAT3 BIT(7)
+#define SD_OVRRD_CLK_OEN BIT(11)
+#define SD_FORCE_CLK_ON BIT(12)
#define SD_SPI_MODE 0x108
#define SD_CE_ATA_1 0x10C
@@ -64,6 +68,7 @@ struct sdhci_pxa {
u8 power_mode;
void __iomem *sdio3_conf_reg;
void __iomem *mbus_win_regs;
+ bool dat3_cd_enabled;
};
/*
@@ -160,13 +165,36 @@ static int armada_38x_quirks(struct platform_device *pdev,
}
host->caps1 &= ~(SDHCI_SUPPORT_SDR104 | SDHCI_USE_SDR50_TUNING);
+ if (of_property_read_bool(np, "dat3-cd") &&
+ !of_property_read_bool(np, "broken-cd"))
+ pxa->dat3_cd_enabled = true;
+
return 0;
}
+static void pxav3_set_clock(struct sdhci_host *host, unsigned int clock)
+{
+ struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+ struct sdhci_pxa *pxa = pltfm_host->priv;
+
+ sdhci_set_clock(host, clock);
+
+ /*
+ * The interface clock enable is also used as control
+ * for the A38x SDIO IP, so it can't be powered down
+ * when using HW-based card detection.
+ */
+ if (clock == 0 && pxa->dat3_cd_enabled)
+ sdhci_writew(host, SDHCI_CLOCK_INT_EN, SDHCI_CLOCK_CONTROL);
+}
+
static void pxav3_reset(struct sdhci_host *host, u8 mask)
{
struct platform_device *pdev = to_platform_device(mmc_dev(host->mmc));
struct sdhci_pxa_platdata *pdata = pdev->dev.platform_data;
+ struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+ struct sdhci_pxa *pxa = pltfm_host->priv;
+ u32 reg_val;
sdhci_reset(host, mask);
@@ -184,6 +212,21 @@ static void pxav3_reset(struct sdhci_host *host, u8 mask)
tmp |= SDCLK_SEL;
writew(tmp, host->ioaddr + SD_CLOCK_BURST_SIZE_SETUP);
}
+
+ if (pxa->dat3_cd_enabled) {
+ reg_val = sdhci_readl(host, SD_FIFO_PARAM_REG);
+ reg_val |= SD_USE_DAT3 | SD_OVRRD_CLK_OEN |
+ SD_FORCE_CLK_ON;
+ sdhci_writel(host, reg_val, SD_FIFO_PARAM_REG);
+
+ /*
+ * For HW detection based on DAT3 pin keep internal
+ * clk switched on after controller reset.
+ */
+ reg_val = sdhci_readl(host, SDHCI_CLOCK_CONTROL);
+ reg_val |= SDHCI_CLOCK_INT_EN;
+ sdhci_writel(host, reg_val, SDHCI_CLOCK_CONTROL);
+ }
}
}
@@ -211,9 +254,9 @@ static void pxav3_gen_init_74_clocks(struct sdhci_host *host, u8 power_mode)
writew(tmp, host->ioaddr + SD_CE_ATA_2);
/* start sending the 74 clocks */
- tmp = readw(host->ioaddr + SD_CFG_FIFO_PARAM);
+ tmp = readw(host->ioaddr + SD_EXTRA_PARAM_REG);
tmp |= SDCFG_GEN_PAD_CLK_ON;
- writew(tmp, host->ioaddr + SD_CFG_FIFO_PARAM);
+ writew(tmp, host->ioaddr + SD_EXTRA_PARAM_REG);
/* slowest speed is about 100KHz or 10usec per clock */
udelay(740);
@@ -298,7 +341,7 @@ static void pxav3_set_uhs_signaling(struct sdhci_host *host, unsigned int uhs)
}
static const struct sdhci_ops pxav3_sdhci_ops = {
- .set_clock = sdhci_set_clock,
+ .set_clock = pxav3_set_clock,
.platform_send_init_74_clocks = pxav3_gen_init_74_clocks,
.get_max_clock = sdhci_pltfm_clk_get_max_clock,
.set_bus_width = sdhci_set_bus_width,
@@ -407,6 +450,7 @@ static int sdhci_pxav3_probe(struct platform_device *pdev)
sdhci_get_of_property(pdev);
pdata = pxav3_get_mmc_pdata(dev);
pdev->dev.platform_data = pdata;
+
} else if (pdata) {
/* on-chip device */
if (pdata->flags & PXA_FLAG_CARD_PERMANENT)
@@ -438,12 +482,15 @@ static int sdhci_pxav3_probe(struct platform_device *pdev)
}
}
- pm_runtime_get_noresume(&pdev->dev);
- pm_runtime_set_active(&pdev->dev);
- pm_runtime_set_autosuspend_delay(&pdev->dev, PXAV3_RPM_DELAY_MS);
- pm_runtime_use_autosuspend(&pdev->dev);
- pm_runtime_enable(&pdev->dev);
- pm_suspend_ignore_children(&pdev->dev, 1);
+ if (!pxa->dat3_cd_enabled) {
+ pm_runtime_get_noresume(&pdev->dev);
+ pm_runtime_set_active(&pdev->dev);
+ pm_runtime_set_autosuspend_delay(&pdev->dev,
+ PXAV3_RPM_DELAY_MS);
+ pm_runtime_use_autosuspend(&pdev->dev);
+ pm_runtime_enable(&pdev->dev);
+ pm_suspend_ignore_children(&pdev->dev, 1);
+ }
ret = sdhci_add_host(host);
if (ret) {
@@ -456,13 +503,16 @@ static int sdhci_pxav3_probe(struct platform_device *pdev)
if (host->mmc->pm_caps & MMC_PM_WAKE_SDIO_IRQ)
device_init_wakeup(&pdev->dev, 1);
- pm_runtime_put_autosuspend(&pdev->dev);
+ if (!pxa->dat3_cd_enabled)
+ pm_runtime_put_autosuspend(&pdev->dev);
return 0;
err_add_host:
- pm_runtime_disable(&pdev->dev);
- pm_runtime_put_noidle(&pdev->dev);
+ if (!pxa->dat3_cd_enabled) {
+ pm_runtime_disable(&pdev->dev);
+ pm_runtime_put_noidle(&pdev->dev);
+ }
err_of_parse:
err_cd_req:
err_mbus_win:
@@ -479,9 +529,11 @@ static int sdhci_pxav3_remove(struct platform_device *pdev)
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
struct sdhci_pxa *pxa = pltfm_host->priv;
- pm_runtime_get_sync(&pdev->dev);
- pm_runtime_disable(&pdev->dev);
- pm_runtime_put_noidle(&pdev->dev);
+ if (!pxa->dat3_cd_enabled) {
+ pm_runtime_get_sync(&pdev->dev);
+ pm_runtime_disable(&pdev->dev);
+ pm_runtime_put_noidle(&pdev->dev);
+ }
sdhci_remove_host(host, 1);
@@ -498,9 +550,16 @@ static int sdhci_pxav3_suspend(struct device *dev)
{
int ret;
struct sdhci_host *host = dev_get_drvdata(dev);
+ struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+ struct sdhci_pxa *pxa = pltfm_host->priv;
+
+ if (!pxa->dat3_cd_enabled)
+ pm_runtime_get_sync(dev);
- pm_runtime_get_sync(dev);
ret = sdhci_suspend_host(host);
+ if (pxa->dat3_cd_enabled)
+ return ret;
+
pm_runtime_mark_last_busy(dev);
pm_runtime_put_autosuspend(dev);
@@ -518,8 +577,13 @@ static int sdhci_pxav3_resume(struct device *dev)
ret = mv_conf_mbus_windows(dev, pxa->mbus_win_regs,
mv_mbus_dram_info());
- pm_runtime_get_sync(dev);
+ if (!pxa->dat3_cd_enabled)
+ pm_runtime_get_sync(dev);
+
ret = sdhci_resume_host(host);
+ if (pxa->dat3_cd_enabled)
+ return ret;
+
pm_runtime_mark_last_busy(dev);
pm_runtime_put_autosuspend(dev);
--
1.8.3.1
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