[PATCH v4 3/3] mmc: dw_mmc: add an option to force 32-bit access to 64-bit FIFO

From: Sergey Lisov
Date: Sun Mar 12 2023 - 13:03:50 EST

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In reply to: Krzysztof Kozlowski: "Re: [PATCH v4 2/3] arm64: dts: exynos: fix wrong mmc compatible in exynos7885.dtsi"
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Some Samsung Exynos boards using the arm64 architecture have DW MMC
controllers configured for a 32-bit data bus but a 64-bit FIFO. On these
systems the 64-bit FIFO registers must be accessed in two 32-bit halves.
---
drivers/mmc/host/dw_mmc-exynos.c | 41 ++++++++++-
drivers/mmc/host/dw_mmc.c | 122 ++++++++++++++++++++++++++++++-
drivers/mmc/host/dw_mmc.h | 2 +
3 files changed, 162 insertions(+), 3 deletions(-)

diff --git a/drivers/mmc/host/dw_mmc-exynos.c b/drivers/mmc/host/dw_mmc-exynos.c
index 9f20ac524..768774f22 100644
--- a/drivers/mmc/host/dw_mmc-exynos.c
+++ b/drivers/mmc/host/dw_mmc-exynos.c
@@ -28,6 +28,8 @@ enum dw_mci_exynos_type {
DW_MCI_TYPE_EXYNOS5420_SMU,
DW_MCI_TYPE_EXYNOS7,
DW_MCI_TYPE_EXYNOS7_SMU,
+ DW_MCI_TYPE_EXYNOS78XX,
+ DW_MCI_TYPE_EXYNOS78XX_SMU,
DW_MCI_TYPE_ARTPEC8,
};

@@ -70,6 +72,12 @@ static struct dw_mci_exynos_compatible {
}, {
.compatible = "samsung,exynos7-dw-mshc-smu",
.ctrl_type = DW_MCI_TYPE_EXYNOS7_SMU,
+ }, {
+ .compatible = "samsung,exynos78xx-dw-mshc",
+ .ctrl_type = DW_MCI_TYPE_EXYNOS78XX,
+ }, {
+ .compatible = "samsung,exynos78xx-dw-mshc-smu",
+ .ctrl_type = DW_MCI_TYPE_EXYNOS78XX_SMU,
}, {
.compatible = "axis,artpec8-dw-mshc",
.ctrl_type = DW_MCI_TYPE_ARTPEC8,
@@ -86,6 +94,8 @@ static inline u8 dw_mci_exynos_get_ciu_div(struct dw_mci *host)
return EXYNOS4210_FIXED_CIU_CLK_DIV;
else if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU ||
+ priv->ctrl_type == DW_MCI_TYPE_EXYNOS78XX ||
+ priv->ctrl_type == DW_MCI_TYPE_EXYNOS78XX_SMU ||
priv->ctrl_type == DW_MCI_TYPE_ARTPEC8)
return SDMMC_CLKSEL_GET_DIV(mci_readl(host, CLKSEL64)) + 1;
else
@@ -101,7 +111,8 @@ static void dw_mci_exynos_config_smu(struct dw_mci *host)
* set for non-ecryption mode at this time.
*/
if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS5420_SMU ||
- priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU) {
+ priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU ||
+ priv->ctrl_type == DW_MCI_TYPE_EXYNOS78XX_SMU) {
mci_writel(host, MPSBEGIN0, 0);
mci_writel(host, MPSEND0, SDMMC_ENDING_SEC_NR_MAX);
mci_writel(host, MPSCTRL0, SDMMC_MPSCTRL_SECURE_WRITE_BIT |
@@ -127,6 +138,12 @@ static int dw_mci_exynos_priv_init(struct dw_mci *host)
DQS_CTRL_GET_RD_DELAY(priv->saved_strobe_ctrl);
}

+ if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS78XX ||
+ priv->ctrl_type == DW_MCI_TYPE_EXYNOS78XX_SMU) {
+ /* Quirk needed for certain Exynos SoCs */
+ host->quirks |= DW_MMC_QUIRK_FIFO64_32;
+ }
+
if (priv->ctrl_type == DW_MCI_TYPE_ARTPEC8) {
/* Quirk needed for the ARTPEC-8 SoC */
host->quirks |= DW_MMC_QUIRK_EXTENDED_TMOUT;
@@ -144,6 +161,8 @@ static void dw_mci_exynos_set_clksel_timing(struct dw_mci *host, u32 timing)

if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU ||
+ priv->ctrl_type == DW_MCI_TYPE_EXYNOS78XX ||
+ priv->ctrl_type == DW_MCI_TYPE_EXYNOS78XX_SMU ||
priv->ctrl_type == DW_MCI_TYPE_ARTPEC8)
clksel = mci_readl(host, CLKSEL64);
else
@@ -153,6 +172,8 @@ static void dw_mci_exynos_set_clksel_timing(struct dw_mci *host, u32 timing)

if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU ||
+ priv->ctrl_type == DW_MCI_TYPE_EXYNOS78XX ||
+ priv->ctrl_type == DW_MCI_TYPE_EXYNOS78XX_SMU ||
priv->ctrl_type == DW_MCI_TYPE_ARTPEC8)
mci_writel(host, CLKSEL64, clksel);
else
@@ -223,6 +244,8 @@ static int dw_mci_exynos_resume_noirq(struct device *dev)

if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU ||
+ priv->ctrl_type == DW_MCI_TYPE_EXYNOS78XX ||
+ priv->ctrl_type == DW_MCI_TYPE_EXYNOS78XX_SMU ||
priv->ctrl_type == DW_MCI_TYPE_ARTPEC8)
clksel = mci_readl(host, CLKSEL64);
else
@@ -231,6 +254,8 @@ static int dw_mci_exynos_resume_noirq(struct device *dev)
if (clksel & SDMMC_CLKSEL_WAKEUP_INT) {
if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU ||
+ priv->ctrl_type == DW_MCI_TYPE_EXYNOS78XX ||
+ priv->ctrl_type == DW_MCI_TYPE_EXYNOS78XX_SMU ||
priv->ctrl_type == DW_MCI_TYPE_ARTPEC8)
mci_writel(host, CLKSEL64, clksel);
else
@@ -410,6 +435,8 @@ static inline u8 dw_mci_exynos_get_clksmpl(struct dw_mci *host)

if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU ||
+ priv->ctrl_type == DW_MCI_TYPE_EXYNOS78XX ||
+ priv->ctrl_type == DW_MCI_TYPE_EXYNOS78XX_SMU ||
priv->ctrl_type == DW_MCI_TYPE_ARTPEC8)
return SDMMC_CLKSEL_CCLK_SAMPLE(mci_readl(host, CLKSEL64));
else
@@ -423,6 +450,8 @@ static inline void dw_mci_exynos_set_clksmpl(struct dw_mci *host, u8 sample)

if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU ||
+ priv->ctrl_type == DW_MCI_TYPE_EXYNOS78XX ||
+ priv->ctrl_type == DW_MCI_TYPE_EXYNOS78XX_SMU ||
priv->ctrl_type == DW_MCI_TYPE_ARTPEC8)
clksel = mci_readl(host, CLKSEL64);
else
@@ -430,6 +459,8 @@ static inline void dw_mci_exynos_set_clksmpl(struct dw_mci *host, u8 sample)
clksel = SDMMC_CLKSEL_UP_SAMPLE(clksel, sample);
if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU ||
+ priv->ctrl_type == DW_MCI_TYPE_EXYNOS78XX ||
+ priv->ctrl_type == DW_MCI_TYPE_EXYNOS78XX_SMU ||
priv->ctrl_type == DW_MCI_TYPE_ARTPEC8)
mci_writel(host, CLKSEL64, clksel);
else
@@ -444,6 +475,8 @@ static inline u8 dw_mci_exynos_move_next_clksmpl(struct dw_mci *host)

if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU ||
+ priv->ctrl_type == DW_MCI_TYPE_EXYNOS78XX ||
+ priv->ctrl_type == DW_MCI_TYPE_EXYNOS78XX_SMU ||
priv->ctrl_type == DW_MCI_TYPE_ARTPEC8)
clksel = mci_readl(host, CLKSEL64);
else
@@ -454,6 +487,8 @@ static inline u8 dw_mci_exynos_move_next_clksmpl(struct dw_mci *host)

if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU ||
+ priv->ctrl_type == DW_MCI_TYPE_EXYNOS78XX ||
+ priv->ctrl_type == DW_MCI_TYPE_EXYNOS78XX_SMU ||
priv->ctrl_type == DW_MCI_TYPE_ARTPEC8)
mci_writel(host, CLKSEL64, clksel);
else
@@ -633,6 +668,10 @@ static const struct of_device_id dw_mci_exynos_match[] = {
.data = &exynos_drv_data, },
{ .compatible = "samsung,exynos7-dw-mshc-smu",
.data = &exynos_drv_data, },
+ { .compatible = "samsung,exynos78xx-dw-mshc",
+ .data = &exynos_drv_data, },
+ { .compatible = "samsung,exynos78xx-dw-mshc-smu",
+ .data = &exynos_drv_data, },
{ .compatible = "axis,artpec8-dw-mshc",
.data = &artpec_drv_data, },
{},
diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index 581614196..9fe816c61 100644
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -2575,6 +2575,119 @@ static void dw_mci_pull_data64(struct dw_mci *host, void *buf, int cnt)
}
}

+/*
+ Some dw_mmc devices have 64-bit FIFOs, but expect them to be
+ accessed using two 32-bit accesses. If such controller is used
+ with a 64-bit kernel, this has to be done explicitly.
+
+ XXX: Is this issue specific to Exynos7?
+*/
+
+static inline uint64_t mci_fifo_readq_32(void __iomem *addr)
+{
+ uint64_t ans;
+ uint32_t proxy[2];
+
+ proxy[0] = mci_fifo_readl(addr);
+ proxy[1] = mci_fifo_readl(addr+4);
+ memcpy(&ans, proxy, 8);
+ return ans;
+}
+
+static inline void mci_fifo_writeq_32(void __iomem *addr, uint64_t value)
+{
+ uint32_t proxy[2];
+
+ memcpy(proxy, &value, 8);
+ mci_fifo_writel(addr, proxy[0]);
+ mci_fifo_writel(addr+4, proxy[1]);
+}
+
+static void dw_mci_push_data64_32(struct dw_mci *host, void *buf, int cnt)
+{
+ struct mmc_data *data = host->data;
+ int init_cnt = cnt;
+
+ /* try and push anything in the part_buf */
+ if (unlikely(host->part_buf_count)) {
+ int len = dw_mci_push_part_bytes(host, buf, cnt);
+
+ buf += len;
+ cnt -= len;
+
+ if (host->part_buf_count == 8) {
+ mci_fifo_writeq_32(host->fifo_reg, host->part_buf);
+ host->part_buf_count = 0;
+ }
+ }
+#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
+ if (unlikely((unsigned long)buf & 0x7)) {
+ while (cnt >= 8) {
+ u64 aligned_buf[16];
+ int len = min(cnt & -8, (int)sizeof(aligned_buf));
+ int items = len >> 3;
+ int i;
+ /* memcpy from input buffer into aligned buffer */
+ memcpy(aligned_buf, buf, len);
+ buf += len;
+ cnt -= len;
+ /* push data from aligned buffer into fifo */
+ for (i = 0; i < items; ++i)
+ mci_fifo_writeq_32(host->fifo_reg, aligned_buf[i]);
+ }
+ } else
+#endif
+ {
+ u64 *pdata = buf;
+
+ for (; cnt >= 8; cnt -= 8)
+ mci_fifo_writeq_32(host->fifo_reg, *pdata++);
+ buf = pdata;
+ }
+ /* put anything remaining in the part_buf */
+ if (cnt) {
+ dw_mci_set_part_bytes(host, buf, cnt);
+ /* Push data if we have reached the expected data length */
+ if ((data->bytes_xfered + init_cnt) ==
+ (data->blksz * data->blocks))
+ mci_fifo_writeq_32(host->fifo_reg, host->part_buf);
+ }
+}
+
+static void dw_mci_pull_data64_32(struct dw_mci *host, void *buf, int cnt)
+{
+#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
+ if (unlikely((unsigned long)buf & 0x7)) {
+ while (cnt >= 8) {
+ /* pull data from fifo into aligned buffer */
+ u64 aligned_buf[16];
+ int len = min(cnt & -8, (int)sizeof(aligned_buf));
+ int items = len >> 3;
+ int i;
+
+ for (i = 0; i < items; ++i)
+ aligned_buf[i] = mci_fifo_readq_32(host->fifo_reg);
+
+ /* memcpy from aligned buffer into output buffer */
+ memcpy(buf, aligned_buf, len);
+ buf += len;
+ cnt -= len;
+ }
+ } else
+#endif
+ {
+ u64 *pdata = buf;
+
+ for (; cnt >= 8; cnt -= 8)
+ *pdata++ = mci_fifo_readq_32(host->fifo_reg);
+ buf = pdata;
+ }
+ if (cnt) {
+ host->part_buf = mci_fifo_readq_32(host->fifo_reg);
+ dw_mci_pull_final_bytes(host, buf, cnt);
+ }
+}
+
static void dw_mci_pull_data(struct dw_mci *host, void *buf, int cnt)
{
int len;
@@ -3367,8 +3480,13 @@ int dw_mci_probe(struct dw_mci *host)
width = 16;
host->data_shift = 1;
} else if (i == 2) {
- host->push_data = dw_mci_push_data64;
- host->pull_data = dw_mci_pull_data64;
+ if ((host->quirks & DW_MMC_QUIRK_FIFO64_32)) {
+ host->push_data = dw_mci_push_data64_32;
+ host->pull_data = dw_mci_pull_data64_32;
+ } else {
+ host->push_data = dw_mci_push_data64;
+ host->pull_data = dw_mci_pull_data64;
+ }
width = 64;
host->data_shift = 3;
} else {
diff --git a/drivers/mmc/host/dw_mmc.h b/drivers/mmc/host/dw_mmc.h
index 4ed81f94f..edd642b92 100644
--- a/drivers/mmc/host/dw_mmc.h
+++ b/drivers/mmc/host/dw_mmc.h
@@ -280,6 +280,8 @@ struct dw_mci_board {

/* Support for longer data read timeout */
#define DW_MMC_QUIRK_EXTENDED_TMOUT BIT(0)
+/* Force 32-bit access to the FIFO */
+#define DW_MMC_QUIRK_FIFO64_32 BIT(1)

#define DW_MMC_240A 0x240a
#define DW_MMC_280A 0x280a
--
2.38.3

Next message: Krzysztof Kozlowski: "Re: [PATCH] ARM: dts: exynos: fix MCT compatible in Universal C210"
Previous message: Krzysztof Kozlowski: "Re: [PATCH v3 0/7] media: dt-bindings: Convert Samsung SoC Camera to DT schema"
In reply to: Krzysztof Kozlowski: "Re: [PATCH v4 2/3] arm64: dts: exynos: fix wrong mmc compatible in exynos7885.dtsi"
Next in thread: Krzysztof Kozlowski: "Re: [PATCH v4 3/3] mmc: dw_mmc: add an option to force 32-bit access to 64-bit FIFO"
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