[PATCH 2/3] mmc: sdhci-of-aspeed: Expose data sample phase delay tuning
Andrew Jeffery
andrew at aj.id.au
Thu Sep 10 20:54:39 AEST 2020
Allow sample phase adjustment to deal with layout or tolerance issues.
Signed-off-by: Andrew Jeffery <andrew at aj.id.au>
---
drivers/mmc/host/sdhci-of-aspeed.c | 137 +++++++++++++++++++++++++++--
1 file changed, 132 insertions(+), 5 deletions(-)
diff --git a/drivers/mmc/host/sdhci-of-aspeed.c b/drivers/mmc/host/sdhci-of-aspeed.c
index 4f008ba3280e..641accbfcde4 100644
--- a/drivers/mmc/host/sdhci-of-aspeed.c
+++ b/drivers/mmc/host/sdhci-of-aspeed.c
@@ -16,9 +16,18 @@
#include "sdhci-pltfm.h"
-#define ASPEED_SDC_INFO 0x00
-#define ASPEED_SDC_S1MMC8 BIT(25)
-#define ASPEED_SDC_S0MMC8 BIT(24)
+#define ASPEED_SDC_INFO 0x00
+#define ASPEED_SDC_S1_MMC8 BIT(25)
+#define ASPEED_SDC_S0_MMC8 BIT(24)
+#define ASPEED_SDC_PHASE 0xf4
+#define ASPEED_SDC_S1_PHASE_IN GENMASK(25, 21)
+#define ASPEED_SDC_S0_PHASE_IN GENMASK(20, 16)
+#define ASPEED_SDC_S1_PHASE_OUT GENMASK(15, 11)
+#define ASPEED_SDC_S1_PHASE_IN_EN BIT(10)
+#define ASPEED_SDC_S1_PHASE_OUT_EN GENMASK(9, 8)
+#define ASPEED_SDC_S0_PHASE_OUT GENMASK(7, 3)
+#define ASPEED_SDC_S0_PHASE_IN_EN BIT(2)
+#define ASPEED_SDC_S0_PHASE_OUT_EN GENMASK(1, 0)
struct aspeed_sdc {
struct clk *clk;
@@ -28,9 +37,21 @@ struct aspeed_sdc {
void __iomem *regs;
};
+struct aspeed_sdhci_phase_desc {
+ u32 value_mask;
+ u32 enable_mask;
+ u8 enable_value;
+};
+
+struct aspeed_sdhci_phase {
+ struct aspeed_sdhci_phase_desc in;
+ struct aspeed_sdhci_phase_desc out;
+};
+
struct aspeed_sdhci {
struct aspeed_sdc *parent;
u32 width_mask;
+ const struct aspeed_sdhci_phase *phase;
};
static void aspeed_sdc_configure_8bit_mode(struct aspeed_sdc *sdc,
@@ -50,6 +71,25 @@ static void aspeed_sdc_configure_8bit_mode(struct aspeed_sdc *sdc,
spin_unlock(&sdc->lock);
}
+static void
+aspeed_sdc_configure_phase(struct aspeed_sdc *sdc,
+ const struct aspeed_sdhci_phase_desc *phase,
+ uint8_t value, bool enable)
+{
+ u32 reg;
+
+ spin_lock(&sdc->lock);
+ reg = readl(sdc->regs + ASPEED_SDC_PHASE);
+ reg &= ~phase->enable_mask;
+ if (enable) {
+ reg &= ~phase->value_mask;
+ reg |= value << __ffs(phase->value_mask);
+ reg |= phase->enable_value << __ffs(phase->enable_mask);
+ }
+ writel(reg, sdc->regs + ASPEED_SDC_PHASE);
+ spin_unlock(&sdc->lock);
+}
+
static void aspeed_sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
{
struct sdhci_pltfm_host *pltfm_host;
@@ -155,8 +195,58 @@ static inline int aspeed_sdhci_calculate_slot(struct aspeed_sdhci *dev,
return (delta / 0x100) - 1;
}
+static int aspeed_sdhci_configure_of(struct platform_device *pdev,
+ struct aspeed_sdhci *sdhci)
+{
+ u32 iphase, ophase;
+ struct device_node *np;
+ struct device *dev;
+ int ret;
+
+ if (!sdhci->phase)
+ return 0;
+
+ dev = &pdev->dev;
+ np = dev->of_node;
+
+ ret = of_property_read_u32(np, "aspeed,input-phase", &iphase);
+ if (ret < 0) {
+ aspeed_sdc_configure_phase(sdhci->parent, &sdhci->phase->in, 0,
+ false);
+ dev_dbg(dev, "Input phase configuration disabled");
+ } else if (iphase >= (1 << 5)) {
+ dev_err(dev,
+ "Input phase value exceeds field range (5 bits): %u",
+ iphase);
+ return -ERANGE;
+ } else {
+ aspeed_sdc_configure_phase(sdhci->parent, &sdhci->phase->in,
+ iphase, true);
+ dev_info(dev, "Input phase relationship: %u", iphase);
+ }
+
+ ret = of_property_read_u32(np, "aspeed,output-phase", &ophase);
+ if (ret < 0) {
+ aspeed_sdc_configure_phase(sdhci->parent, &sdhci->phase->out, 0,
+ false);
+ dev_dbg(dev, "Output phase configuration disabled");
+ } else if (ophase >= (1 << 5)) {
+ dev_err(dev,
+ "Output phase value exceeds field range (5 bits): %u",
+ iphase);
+ return -ERANGE;
+ } else {
+ aspeed_sdc_configure_phase(sdhci->parent, &sdhci->phase->out,
+ ophase, true);
+ dev_info(dev, "Output phase relationship: %u", ophase);
+ }
+
+ return 0;
+}
+
static int aspeed_sdhci_probe(struct platform_device *pdev)
{
+ const struct aspeed_sdhci_phase *phase;
struct sdhci_pltfm_host *pltfm_host;
struct aspeed_sdhci *dev;
struct sdhci_host *host;
@@ -181,7 +271,10 @@ static int aspeed_sdhci_probe(struct platform_device *pdev)
return -EINVAL;
dev_info(&pdev->dev, "Configuring for slot %d\n", slot);
- dev->width_mask = !slot ? ASPEED_SDC_S0MMC8 : ASPEED_SDC_S1MMC8;
+ dev->width_mask = !slot ? ASPEED_SDC_S0_MMC8 : ASPEED_SDC_S1_MMC8;
+ phase = of_device_get_match_data(&pdev->dev);
+ if (phase)
+ dev->phase = &phase[slot];
sdhci_get_of_property(pdev);
@@ -195,6 +288,10 @@ static int aspeed_sdhci_probe(struct platform_device *pdev)
goto err_pltfm_free;
}
+ ret = aspeed_sdhci_configure_of(pdev, dev);
+ if (ret)
+ goto err_sdhci_add;
+
ret = mmc_of_parse(host->mmc);
if (ret)
goto err_sdhci_add;
@@ -230,10 +327,40 @@ static int aspeed_sdhci_remove(struct platform_device *pdev)
return 0;
}
+static const struct aspeed_sdhci_phase ast2600_sdhci_phase[] = {
+ /* SDHCI/Slot 0 */
+ [0] = {
+ .in = {
+ .value_mask = ASPEED_SDC_S0_PHASE_IN,
+ .enable_mask = ASPEED_SDC_S0_PHASE_IN_EN,
+ .enable_value = 1,
+ },
+ .out = {
+ .value_mask = ASPEED_SDC_S0_PHASE_OUT,
+ .enable_mask = ASPEED_SDC_S0_PHASE_OUT_EN,
+ .enable_value = 3,
+ },
+ },
+ /* SDHCI/Slot 1 */
+ [1] = {
+ .in = {
+ .value_mask = ASPEED_SDC_S1_PHASE_IN,
+ .enable_mask = ASPEED_SDC_S1_PHASE_IN_EN,
+ .enable_value = 1,
+ },
+ .out = {
+ .value_mask = ASPEED_SDC_S1_PHASE_OUT,
+ .enable_mask = ASPEED_SDC_S1_PHASE_OUT_EN,
+ .enable_value = 3,
+ },
+ },
+};
+
+/* If supported, phase adjustment fields are stored in the data pointer */
static const struct of_device_id aspeed_sdhci_of_match[] = {
{ .compatible = "aspeed,ast2400-sdhci", },
{ .compatible = "aspeed,ast2500-sdhci", },
- { .compatible = "aspeed,ast2600-sdhci", },
+ { .compatible = "aspeed,ast2600-sdhci", .data = ast2600_sdhci_phase },
{ }
};
--
2.25.1
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