[PATCH v5 3/3] rockchip: sdhci: Add HS400 Enhanced Strobe support for RK3568
Alper Nebi Yasak
alpernebiyasak at gmail.com
Tue Mar 15 18:46:28 CET 2022
On RK3568, a register bit must be set to enable Enhanced Strobe.
However, it appears that the address of this register may differ from
vendor to vendor and should be read from the underlying MMC IP. Let the
Rockchip SDHCI driver read this address and set the relevant bit when
Enhanced Strobe configuration is requested.
The IP uses a custom mode select value (0x7) for HS400, use that instead
of the common but non-standard SDHCI_CTRL_HS400 value (0x5). Also add
some necessary DLL_STRBIN and DLL_TXCLK configuration for HS400.
Additionally, a bit signifying that the connected hardware is an eMMC
chip must be set to enable Data Strobe for HS400 and HS400ES modes. Also
make the driver set this bit as appropriate.
This is partly ported from Linux's Synopsys DWC MSHC driver which
happens to be the underlying IP. (drivers/mmc/host/sdhci-of-dwcmshc.c in
Linux tree).
Co-developed-by: Yifeng Zhao <yifeng.zhao at rock-chips.com>
Signed-off-by: Yifeng Zhao <yifeng.zhao at rock-chips.com>
Signed-off-by: Alper Nebi Yasak <alpernebiyasak at gmail.com>
---
This is a fixed version I received off-list from Yifeng. I didn't modify
the diff, but added a paragraph in the commit message mentioning their
changes and adjusted the signoffs in the end.
Didn't add the Reviewed-by tag due to changes.
Changes in v5:
- Incorporate RK3568 HS400ES fixes from Yifeng Zhao:
- Use DWCMSHC_CTRL_HS400 = 0x7, instead of SDHCI_CTRL_HS400 = 0x5
- Configure DWCMSHC_CARD_IS_EMMC in rk3568_sdhci_set_ios_post()
- Configure DLL_STRBIN and DLL_TXCLK for HS400.
Changes in v3:
- Set DWCMSHC_CARD_IS_EMMC bit in rk3568_emmc_phy_init()
Changes in v2:
- Rename rk3568_set_enhanced_strobe -> rk3568_sdhci_set_enhanced_strobe
- Let set_enhanced_strobe() unset the ES bit if mode is not HS400_ES
drivers/mmc/rockchip_sdhci.c | 64 ++++++++++++++++++++++++++++++++----
1 file changed, 58 insertions(+), 6 deletions(-)
diff --git a/drivers/mmc/rockchip_sdhci.c b/drivers/mmc/rockchip_sdhci.c
index f4d5a59036a2..f3f9d83ba36f 100644
--- a/drivers/mmc/rockchip_sdhci.c
+++ b/drivers/mmc/rockchip_sdhci.c
@@ -22,6 +22,8 @@
#include <asm/arch-rockchip/clock.h>
#include <asm/arch-rockchip/hardware.h>
+/* DWCMSHC specific Mode Select value */
+#define DWCMSHC_CTRL_HS400 0x7
/* 400KHz is max freq for card ID etc. Use that as min */
#define EMMC_MIN_FREQ 400000
#define KHz (1000)
@@ -45,6 +47,14 @@
#define ARASAN_VENDOR_REGISTER 0x78
#define ARASAN_VENDOR_ENHANCED_STROBE BIT(0)
+/* DWC IP vendor area 1 pointer */
+#define DWCMSHC_P_VENDOR_AREA1 0xe8
+#define DWCMSHC_AREA1_MASK GENMASK(11, 0)
+/* Offset inside the vendor area 1 */
+#define DWCMSHC_EMMC_CONTROL 0x2c
+#define DWCMSHC_CARD_IS_EMMC BIT(0)
+#define DWCMSHC_ENHANCED_STROBE BIT(8)
+
/* Rockchip specific Registers */
#define DWCMSHC_EMMC_DLL_CTRL 0x800
#define DWCMSHC_EMMC_DLL_CTRL_RESET BIT(1)
@@ -60,8 +70,14 @@
#define DWCMSHC_EMMC_DLL_INC_VALUE 2
#define DWCMSHC_EMMC_DLL_INC 8
#define DWCMSHC_EMMC_DLL_DLYENA BIT(27)
-#define DLL_TXCLK_TAPNUM_DEFAULT 0x10
-#define DLL_STRBIN_TAPNUM_DEFAULT 0x3
+#define DLL_TXCLK_TAPNUM_DEFAULT 0xA
+
+#define DLL_STRBIN_TAPNUM_DEFAULT 0x8
+#define DLL_STRBIN_TAPNUM_FROM_SW BIT(24)
+#define DLL_STRBIN_DELAY_NUM_SEL BIT(26)
+#define DLL_STRBIN_DELAY_NUM_OFFSET 16
+#define DLL_STRBIN_DELAY_NUM_DEFAULT 0x16
+
#define DLL_TXCLK_TAPNUM_FROM_SW BIT(24)
#define DWCMSHC_EMMC_DLL_LOCKED BIT(8)
#define DWCMSHC_EMMC_DLL_TIMEOUT BIT(9)
@@ -327,7 +343,8 @@ static int rk3568_sdhci_emmc_set_clock(struct sdhci_host *host, unsigned int clo
sdhci_writel(host, extra, DWCMSHC_EMMC_DLL_TXCLK);
extra = DWCMSHC_EMMC_DLL_DLYENA |
- DLL_STRBIN_TAPNUM_DEFAULT;
+ DLL_STRBIN_TAPNUM_DEFAULT |
+ DLL_STRBIN_TAPNUM_FROM_SW;
sdhci_writel(host, extra, DWCMSHC_EMMC_DLL_STRBIN);
} else {
/* reset the clock phase when the frequency is lower than 100MHz */
@@ -335,7 +352,15 @@ static int rk3568_sdhci_emmc_set_clock(struct sdhci_host *host, unsigned int clo
extra = DLL_RXCLK_NO_INVERTER << DWCMSHC_EMMC_DLL_RXCLK_SRCSEL;
sdhci_writel(host, extra, DWCMSHC_EMMC_DLL_RXCLK);
sdhci_writel(host, 0, DWCMSHC_EMMC_DLL_TXCLK);
- sdhci_writel(host, 0, DWCMSHC_EMMC_DLL_STRBIN);
+ /*
+ * Before switching to hs400es mode, the driver will enable
+ * enhanced strobe first. PHY needs to configure the parameters
+ * of enhanced strobe first.
+ */
+ extra = DWCMSHC_EMMC_DLL_DLYENA |
+ DLL_STRBIN_DELAY_NUM_SEL |
+ DLL_STRBIN_DELAY_NUM_DEFAULT << DLL_STRBIN_DELAY_NUM_OFFSET;
+ sdhci_writel(host, extra, DWCMSHC_EMMC_DLL_STRBIN);
}
return 0;
@@ -346,11 +371,30 @@ static int rk3568_emmc_get_phy(struct udevice *dev)
return 0;
}
+static int rk3568_sdhci_set_enhanced_strobe(struct sdhci_host *host)
+{
+ struct mmc *mmc = host->mmc;
+ u32 vendor;
+ int reg;
+
+ reg = (sdhci_readl(host, DWCMSHC_P_VENDOR_AREA1) & DWCMSHC_AREA1_MASK)
+ + DWCMSHC_EMMC_CONTROL;
+
+ vendor = sdhci_readl(host, reg);
+ if (mmc->selected_mode == MMC_HS_400_ES)
+ vendor |= DWCMSHC_ENHANCED_STROBE;
+ else
+ vendor &= ~DWCMSHC_ENHANCED_STROBE;
+ sdhci_writel(host, vendor, reg);
+
+ return 0;
+}
+
static int rk3568_sdhci_set_ios_post(struct sdhci_host *host)
{
struct mmc *mmc = host->mmc;
uint clock = mmc->tran_speed;
- u32 reg;
+ u32 reg, vendor_reg;
if (!clock)
clock = mmc->clock;
@@ -360,8 +404,15 @@ static int rk3568_sdhci_set_ios_post(struct sdhci_host *host)
if (mmc->selected_mode == MMC_HS_400 || mmc->selected_mode == MMC_HS_400_ES) {
reg = sdhci_readw(host, SDHCI_HOST_CONTROL2);
reg &= ~SDHCI_CTRL_UHS_MASK;
- reg |= SDHCI_CTRL_HS400;
+ reg |= DWCMSHC_CTRL_HS400;
sdhci_writew(host, reg, SDHCI_HOST_CONTROL2);
+
+ vendor_reg = (sdhci_readl(host, DWCMSHC_P_VENDOR_AREA1) & DWCMSHC_AREA1_MASK)
+ + DWCMSHC_EMMC_CONTROL;
+ /* set CARD_IS_EMMC bit to enable Data Strobe for HS400 */
+ reg = sdhci_readw(host, vendor_reg);
+ reg |= DWCMSHC_CARD_IS_EMMC;
+ sdhci_writew(host, reg, vendor_reg);
} else {
sdhci_set_uhs_timing(host);
}
@@ -554,6 +605,7 @@ static const struct sdhci_data rk3568_data = {
.get_phy = rk3568_emmc_get_phy,
.emmc_phy_init = rk3568_emmc_phy_init,
.set_ios_post = rk3568_sdhci_set_ios_post,
+ .set_enhanced_strobe = rk3568_sdhci_set_enhanced_strobe,
};
static const struct udevice_id sdhci_ids[] = {
--
2.35.1
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