Hello Ulf and Adrian,
This patch is going to support enhanced strobe function
for emmc version 5.1+ introduced by JEDEC recently.
Enchanced strobe is a optional function, so we add a new cap* for drivers to
decide whether to use it.
When introduing hs400 mode, JEDEC asks controllers to use data strobe line
to latch the data from emmc devives. But for cmd-reponse, not mentioned yet.
Since emmc version 5.1 published, JEDEC adds enhanced strobe function to deal
with cmd-response the same way as data-read. This feature is optional.
>From the spec(section 6.6.2.3), the standard scenario to select HS400 enhanced
strobe mode illustrated like this:
(1) set HS_TIMIMG (Highspeed)
(2) Host change freq to <= 52Mhz
(3) set the bus width to Enhanced strobe and DDR8Bit(CMD6), EXT_CSD[183] = 0x86
instead of 0x80
(4) set HS_TIMING to 0x3 (HS400)
(5) Host change freq to <= 200Mhz
(6) Host select HS400 enhanced strobe complete
I can't find a upstreamed controller claimed to support it, as well as the
mmc stack. But my "arasan,sdhci-5.1" actually supports this function. So I decide
to work for this part.
By looking into the SDHCI spec, I find there isn't any registers to enable the
enhanced strobe function. But from my "arasan,sdhci-5.1" databook, it describes a
register called VENDOR_REGISTER(0x78) to trigger this mode. So I guess other sdhci
variant drivers may also need s vendor specific register to deal with it.
If we are sure that our controller supports enhanced strobe mode, just add
mmc-hs400-enhanced-strobe in DT. Once emmc devices claims to support this mode,
we enable it automatically. Of course, other sdhci*/non-sdhci drivers should
implement/overwrite the prepare_enhanced_strobe by themselves. I believe all of the
platforms which need to support this mode should do some basic preparation for their
controllers. Currently I just limit the callback within ths scope of arasan,sdhci-5.1,
but I prone to believe arasan will use VENDOR_REGISTER to tirgger this mode from now on
because I do believe vendor will consider the registers' compatibility.
With this patchset applied, we can successfully run in HS400 enhanced strobe mode on
RK3399 platform with Samsung eMMC KLMBG2JENB-B041(v5.1, 16GB).
mmc1: new HS400 Enhanced strobe MMC card at address 0001
mmcblk0: mmc1:0001 AJNB4R 14.6 GiB
mmcblk0boot0: mmc1:0001 AJNB4R partition 1 4.00 MiB
mmcblk0boot1: mmc1:0001 AJNB4R partition 2 4.00 MiB
mmcblk0rpmb: mmc1:0001 AJNB4R partition 3 4.00 MiB
Changes in v2:
- switch to HS400ES from Highspeed mode directly
Shawn Lin (6):
Documentation: mmc: add mmc-hs400-enhanced-strobe
mmc: core: add mmc-hs400-enhanced-strobe support
mmc: core: implement enhanced strobe support
mmc: debugfs: add HS400 enhanced strobe description
mmc: sdhci: implement enhanced strobe callback
mmc: sdhci-of-arasan: overwrite enhanced strobe callback
Documentation/devicetree/bindings/mmc/mmc.txt | 1 +
drivers/mmc/core/bus.c | 3 +-
drivers/mmc/core/debugfs.c | 4 +-
drivers/mmc/core/host.c | 2 +
drivers/mmc/core/mmc.c | 77 ++++++++++++++++++++++++---
drivers/mmc/host/sdhci-of-arasan.c | 22 ++++++++
drivers/mmc/host/sdhci.c | 11 ++++
include/linux/mmc/card.h | 1 +
include/linux/mmc/host.h | 18 +++++++
include/linux/mmc/mmc.h | 3 ++
10 files changed, 134 insertions(+), 8 deletions(-)
--
2.3.7
This patch introduce mmc-hs400-enhanced-strobe for platforms
which want to enable enhanced strobe function from DT if the
mmc host controller claims to support enhanced strobe.
Signed-off-by: Shawn Lin <[email protected]>
---
Changes in v2:
- switch to HS400ES from Highspeed mode directly
drivers/mmc/core/host.c | 2 ++
include/linux/mmc/host.h | 6 ++++++
2 files changed, 8 insertions(+)
diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c
index e0a3ee1..eb1530a 100644
--- a/drivers/mmc/core/host.c
+++ b/drivers/mmc/core/host.c
@@ -289,6 +289,8 @@ int mmc_of_parse(struct mmc_host *host)
host->caps2 |= MMC_CAP2_HS400_1_8V | MMC_CAP2_HS200_1_8V_SDR;
if (of_property_read_bool(np, "mmc-hs400-1_2v"))
host->caps2 |= MMC_CAP2_HS400_1_2V | MMC_CAP2_HS200_1_2V_SDR;
+ if (of_property_read_bool(np, "mmc-hs400-enhanced-strobe"))
+ host->caps2 |= MMC_CAP2_HS400_ENHANCED_STROBE;
host->dsr_req = !of_property_read_u32(np, "dsr", &host->dsr);
if (host->dsr_req && (host->dsr & ~0xffff)) {
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index 85800b4..11e89d3 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -302,6 +302,7 @@ struct mmc_host {
#define MMC_CAP2_SDIO_IRQ_NOTHREAD (1 << 17)
#define MMC_CAP2_NO_WRITE_PROTECT (1 << 18) /* No physical write protect pin, assume that card is always read-write */
#define MMC_CAP2_NO_SDIO (1 << 19) /* Do not send SDIO commands during initialization */
+#define MMC_CAP2_HS400_ENHANCED_STROBE (1 << 20) /* Host supports enhanced strobe */
mmc_pm_flag_t pm_caps; /* supported pm features */
@@ -480,6 +481,11 @@ static inline int mmc_host_uhs(struct mmc_host *host)
MMC_CAP_UHS_DDR50);
}
+static inline int mmc_host_hs400_enhanced_strobe(struct mmc_host *host)
+{
+ return host->caps2 & MMC_CAP2_HS400_ENHANCED_STROBE;
+}
+
static inline int mmc_host_packed_wr(struct mmc_host *host)
{
return host->caps2 & MMC_CAP2_PACKED_WR;
--
2.3.7
We inctroduce HS400 with enhanced strobe function, so we need
add it for debug show.
Signed-off-by: Shawn Lin <[email protected]>
---
Changes in v2: None
drivers/mmc/core/debugfs.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/mmc/core/debugfs.c b/drivers/mmc/core/debugfs.c
index 9382a57..51d7c38 100644
--- a/drivers/mmc/core/debugfs.c
+++ b/drivers/mmc/core/debugfs.c
@@ -148,7 +148,9 @@ static int mmc_ios_show(struct seq_file *s, void *data)
str = "mmc HS200";
break;
case MMC_TIMING_MMC_HS400:
- str = "mmc HS400";
+ mmc_card_hs400es(host->card) ?
+ (str = "mmc HS400 enhanced strobe") :
+ (str = "mmc HS400");
break;
default:
str = "invalid";
--
2.3.7
Enhanced strobe stuff currently is beyond the scope
of Secure Digital Host Controller Interface. So we can't
find a register here to enable/disable it. We experct
variant drivers to finish the details according to their
vendor settings.
Signed-off-by: Shawn Lin <[email protected]>
---
Changes in v2: None
drivers/mmc/host/sdhci.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 94cffa7..a04e4c4 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -2049,6 +2049,16 @@ out_unlock:
return err;
}
+static int sdhci_prepare_enhanced_strobe(struct mmc_host *mmc, bool enable)
+{
+ /*
+ * Currently we can't find a register to enable enhanced strobe
+ * function for standard sdhci, so we expect variant drivers to
+ * overwrite it.
+ */
+ return -EINVAL;
+}
+
static int sdhci_select_drive_strength(struct mmc_card *card,
unsigned int max_dtr, int host_drv,
int card_drv, int *drv_type)
@@ -2158,6 +2168,7 @@ static const struct mmc_host_ops sdhci_ops = {
.enable_sdio_irq = sdhci_enable_sdio_irq,
.start_signal_voltage_switch = sdhci_start_signal_voltage_switch,
.prepare_hs400_tuning = sdhci_prepare_hs400_tuning,
+ .prepare_enhanced_strobe = sdhci_prepare_enhanced_strobe,
.execute_tuning = sdhci_execute_tuning,
.select_drive_strength = sdhci_select_drive_strength,
.card_event = sdhci_card_event,
--
2.3.7
Currently sdhci-arasan 5.1 can support enhanced strobe function,
and we now limit it just for "arasan,sdhci-5.1". Add
mmc-hs400-enhanced-strobe in DT to enable the function if we'r sure
our controller can support it.
Signed-off-by: Shawn Lin <[email protected]>
---
Changes in v2: None
drivers/mmc/host/sdhci-of-arasan.c | 22 ++++++++++++++++++++++
1 file changed, 22 insertions(+)
diff --git a/drivers/mmc/host/sdhci-of-arasan.c b/drivers/mmc/host/sdhci-of-arasan.c
index 20b859e..a0e4536 100644
--- a/drivers/mmc/host/sdhci-of-arasan.c
+++ b/drivers/mmc/host/sdhci-of-arasan.c
@@ -25,7 +25,9 @@
#include "sdhci-pltfm.h"
#define SDHCI_ARASAN_CLK_CTRL_OFFSET 0x2c
+#define SDHCI_ARASAN_VENDOR_REGISTER 0x78
+#define VENDOR_ENHANCED_STROBE BIT(0)
#define CLK_CTRL_TIMEOUT_SHIFT 16
#define CLK_CTRL_TIMEOUT_MASK (0xf << CLK_CTRL_TIMEOUT_SHIFT)
#define CLK_CTRL_TIMEOUT_MIN_EXP 13
@@ -73,6 +75,23 @@ static void sdhci_arasan_set_clock(struct sdhci_host *host, unsigned int clock)
phy_power_on(sdhci_arasan->phy);
}
+static int sdhci_arasan_enhanced_strobe(struct mmc_host *mmc,
+ bool enable)
+{
+ u32 vendor;
+ struct sdhci_host *host = mmc_priv(mmc);
+
+ vendor = readl(host->ioaddr + SDHCI_ARASAN_VENDOR_REGISTER);
+ if (enable)
+ vendor |= VENDOR_ENHANCED_STROBE;
+ else
+ vendor &= (~VENDOR_ENHANCED_STROBE);
+
+ writel(vendor, host->ioaddr + SDHCI_ARASAN_VENDOR_REGISTER);
+
+ return 0;
+}
+
static struct sdhci_ops sdhci_arasan_ops = {
.set_clock = sdhci_arasan_set_clock,
.get_max_clock = sdhci_pltfm_clk_get_max_clock,
@@ -239,6 +258,9 @@ static int sdhci_arasan_probe(struct platform_device *pdev)
dev_err(&pdev->dev, "phy_power_on err.\n");
goto err_phy_power;
}
+
+ host->mmc_host_ops.prepare_enhanced_strobe =
+ sdhci_arasan_enhanced_strobe;
}
ret = sdhci_add_host(host);
--
2.3.7
Controllers use data strobe line to latch data from devices
under hs400 mode, but not for cmd line. So since emmc 5.1, JEDEC
introduces enhanced strobe mode for latching cmd response from
emmc devices to host controllers. This new feature is optional,
so it depends both on device's cap and host's cap to decide
whether to use it or not.
Signed-off-by: Shawn Lin <[email protected]>
---
Changes in v2: None
drivers/mmc/core/bus.c | 3 +-
drivers/mmc/core/mmc.c | 77 ++++++++++++++++++++++++++++++++++++++++++++----
include/linux/mmc/card.h | 1 +
include/linux/mmc/host.h | 12 ++++++++
include/linux/mmc/mmc.h | 3 ++
5 files changed, 89 insertions(+), 7 deletions(-)
diff --git a/drivers/mmc/core/bus.c b/drivers/mmc/core/bus.c
index 4bc48f1..7e94b9d 100644
--- a/drivers/mmc/core/bus.c
+++ b/drivers/mmc/core/bus.c
@@ -332,12 +332,13 @@ int mmc_add_card(struct mmc_card *card)
mmc_card_ddr52(card) ? "DDR " : "",
type);
} else {
- pr_info("%s: new %s%s%s%s%s card at address %04x\n",
+ pr_info("%s: new %s%s%s%s%s%s card at address %04x\n",
mmc_hostname(card->host),
mmc_card_uhs(card) ? "ultra high speed " :
(mmc_card_hs(card) ? "high speed " : ""),
mmc_card_hs400(card) ? "HS400 " :
(mmc_card_hs200(card) ? "HS200 " : ""),
+ mmc_card_hs400es(card) ? "Enhanced strobe" : "",
mmc_card_ddr52(card) ? "DDR " : "",
uhs_bus_speed_mode, type, card->rca);
}
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 28b477d..f45ed10 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -235,6 +235,12 @@ static void mmc_select_card_type(struct mmc_card *card)
avail_type |= EXT_CSD_CARD_TYPE_HS400_1_2V;
}
+ if ((caps2 & MMC_CAP2_HS400_ENHANCED_STROBE) &&
+ card->ext_csd.strobe_support &&
+ ((card_type & EXT_CSD_CARD_TYPE_HS400_1_2V) ||
+ (card_type & EXT_CSD_CARD_TYPE_HS400_1_8V)))
+ avail_type |= EXT_CSD_CARD_TYPE_HS400ES;
+
card->ext_csd.hs_max_dtr = hs_max_dtr;
card->ext_csd.hs200_max_dtr = hs200_max_dtr;
card->mmc_avail_type = avail_type;
@@ -383,6 +389,7 @@ static int mmc_decode_ext_csd(struct mmc_card *card, u8 *ext_csd)
mmc_card_set_blockaddr(card);
}
+ card->ext_csd.strobe_support = ext_csd[EXT_CSD_STROBE_SUPPORT];
card->ext_csd.raw_card_type = ext_csd[EXT_CSD_CARD_TYPE];
mmc_select_card_type(card);
@@ -1062,9 +1069,10 @@ static int mmc_select_hs400(struct mmc_card *card)
u8 val;
/*
- * HS400 mode requires 8-bit bus width
+ * HS400(ES) mode requires 8-bit bus width
*/
- if (!(card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS400 &&
+ if (!(((card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS400) ||
+ (card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS400ES)) &&
host->ios.bus_width == MMC_BUS_WIDTH_8))
return 0;
@@ -1097,9 +1105,26 @@ static int mmc_select_hs400(struct mmc_card *card)
}
/* Switch card to DDR */
+ val = EXT_CSD_DDR_BUS_WIDTH_8;
+ if (card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS400ES) {
+ val |= EXT_CSD_BUS_WIDTH_STROBE;
+ /*
+ * Make sure we are in non-enhanced strobe mode before we
+ * actually enable it in ext_csd.
+ */
+ if (host->ops->prepare_enhanced_strobe)
+ err = host->ops->prepare_enhanced_strobe(host, false);
+
+ if (err) {
+ pr_err("%s: unprepare_enhanced strobe failed, err:%d\n",
+ mmc_hostname(host), err);
+ return err;
+ }
+ }
+
err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
EXT_CSD_BUS_WIDTH,
- EXT_CSD_DDR_BUS_WIDTH_8,
+ val,
card->ext_csd.generic_cmd6_time);
if (err) {
pr_err("%s: switch to bus width for hs400 failed, err:%d\n",
@@ -1124,6 +1149,35 @@ static int mmc_select_hs400(struct mmc_card *card)
mmc_set_timing(host, MMC_TIMING_MMC_HS400);
mmc_set_bus_speed(card);
+ if (card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS400ES) {
+ /* Controller enable enhanced strobe function */
+ if (host->ops->prepare_enhanced_strobe)
+ err = host->ops->prepare_enhanced_strobe(host, true);
+
+ if (err) {
+ pr_err("%s: prepare enhanced strobe failed, err:%d\n",
+ mmc_hostname(host), err);
+ return err;
+ }
+
+ /*
+ * After switching to hs400 enhanced strobe mode, we expect to
+ * verify whether it works or not. If controller can't handle
+ * bus width test, compare ext_csd previously read in 1 bit mode
+ * against ext_csd at new bus width
+ */
+ if (!(host->caps & MMC_CAP_BUS_WIDTH_TEST))
+ err = mmc_compare_ext_csds(card, MMC_BUS_WIDTH_8);
+ else
+ err = mmc_bus_test(card, MMC_BUS_WIDTH_8);
+
+ if (err) {
+ pr_warn("%s: switch to enhanced strobe failed\n",
+ mmc_hostname(host));
+ return err;
+ }
+ }
+
if (!send_status) {
err = mmc_switch_status(card);
if (err)
@@ -1297,7 +1351,8 @@ err:
}
/*
- * Activate High Speed or HS200 mode if supported.
+ * Activate High Speed or HS200 mode if supported. For HS400
+ * with enhanced strobe mode, we should activate High Speed.
*/
static int mmc_select_timing(struct mmc_card *card)
{
@@ -1306,7 +1361,9 @@ static int mmc_select_timing(struct mmc_card *card)
if (!mmc_can_ext_csd(card))
goto bus_speed;
- if (card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS200)
+ if (card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS400ES)
+ err = mmc_select_hs(card);
+ else if (card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS200)
err = mmc_select_hs200(card);
else if (card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS)
err = mmc_select_hs(card);
@@ -1578,7 +1635,15 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
} else if (mmc_card_hs(card)) {
/* Select the desired bus width optionally */
err = mmc_select_bus_width(card);
- if (!IS_ERR_VALUE(err)) {
+ if (IS_ERR_VALUE(err))
+ goto free_card;
+
+ if (card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS400ES) {
+ /* Directly from HS to HS400-ES */
+ err = mmc_select_hs400(card);
+ if (err)
+ goto free_card;
+ } else {
err = mmc_select_hs_ddr(card);
if (err)
goto free_card;
diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index eb0151b..22defc2 100644
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -95,6 +95,7 @@ struct mmc_ext_csd {
u8 raw_partition_support; /* 160 */
u8 raw_rpmb_size_mult; /* 168 */
u8 raw_erased_mem_count; /* 181 */
+ u8 strobe_support; /* 184 */
u8 raw_ext_csd_structure; /* 194 */
u8 raw_card_type; /* 196 */
u8 raw_driver_strength; /* 197 */
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index 11e89d3..19de56c 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -19,6 +19,7 @@
#include <linux/mmc/core.h>
#include <linux/mmc/card.h>
+#include <linux/mmc/mmc.h>
#include <linux/mmc/pm.h>
struct mmc_ios {
@@ -143,6 +144,8 @@ struct mmc_host_ops {
/* Prepare HS400 target operating frequency depending host driver */
int (*prepare_hs400_tuning)(struct mmc_host *host, struct mmc_ios *ios);
+ /* Prepare enhanced strobe depending host driver */
+ int (*prepare_enhanced_strobe)(struct mmc_host *host, bool enable);
int (*select_drive_strength)(struct mmc_card *card,
unsigned int max_dtr, int host_drv,
int card_drv, int *drv_type);
@@ -518,6 +521,15 @@ static inline bool mmc_card_hs400(struct mmc_card *card)
return card->host->ios.timing == MMC_TIMING_MMC_HS400;
}
+static inline bool mmc_card_hs400es(struct mmc_card *card)
+{
+ if (mmc_card_hs400(card) &&
+ (card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS400ES))
+ return 1;
+
+ return 0;
+}
+
void mmc_retune_timer_stop(struct mmc_host *host);
static inline void mmc_retune_needed(struct mmc_host *host)
diff --git a/include/linux/mmc/mmc.h b/include/linux/mmc/mmc.h
index 15f2c4a..c376209 100644
--- a/include/linux/mmc/mmc.h
+++ b/include/linux/mmc/mmc.h
@@ -297,6 +297,7 @@ struct _mmc_csd {
#define EXT_CSD_PART_CONFIG 179 /* R/W */
#define EXT_CSD_ERASED_MEM_CONT 181 /* RO */
#define EXT_CSD_BUS_WIDTH 183 /* R/W */
+#define EXT_CSD_STROBE_SUPPORT 184 /* RO */
#define EXT_CSD_HS_TIMING 185 /* R/W */
#define EXT_CSD_POWER_CLASS 187 /* R/W */
#define EXT_CSD_REV 192 /* RO */
@@ -380,12 +381,14 @@ struct _mmc_csd {
#define EXT_CSD_CARD_TYPE_HS400_1_2V (1<<7) /* Card can run at 200MHz DDR, 1.2V */
#define EXT_CSD_CARD_TYPE_HS400 (EXT_CSD_CARD_TYPE_HS400_1_8V | \
EXT_CSD_CARD_TYPE_HS400_1_2V)
+#define EXT_CSD_CARD_TYPE_HS400ES (1<<8) /* Card can run at HS400ES */
#define EXT_CSD_BUS_WIDTH_1 0 /* Card is in 1 bit mode */
#define EXT_CSD_BUS_WIDTH_4 1 /* Card is in 4 bit mode */
#define EXT_CSD_BUS_WIDTH_8 2 /* Card is in 8 bit mode */
#define EXT_CSD_DDR_BUS_WIDTH_4 5 /* Card is in 4 bit DDR mode */
#define EXT_CSD_DDR_BUS_WIDTH_8 6 /* Card is in 8 bit DDR mode */
+#define EXT_CSD_BUS_WIDTH_STROBE BIT(7) /* Enhanced strobe mode */
#define EXT_CSD_TIMING_BC 0 /* Backwards compatility */
#define EXT_CSD_TIMING_HS 1 /* High speed */
--
2.3.7
mmc-hs400-enhanced-strobe is used to claim that the
host can support hs400 mode with enhanced strobe
introduced by emmc 5.1 spec.
Signed-off-by: Shawn Lin <[email protected]>
---
Changes in v2: None
Documentation/devicetree/bindings/mmc/mmc.txt | 1 +
1 file changed, 1 insertion(+)
diff --git a/Documentation/devicetree/bindings/mmc/mmc.txt b/Documentation/devicetree/bindings/mmc/mmc.txt
index ed23b9b..ecc007a 100644
--- a/Documentation/devicetree/bindings/mmc/mmc.txt
+++ b/Documentation/devicetree/bindings/mmc/mmc.txt
@@ -46,6 +46,7 @@ Optional properties:
- mmc-hs200-1_2v: eMMC HS200 mode(1.2V I/O) is supported
- mmc-hs400-1_8v: eMMC HS400 mode(1.8V I/O) is supported
- mmc-hs400-1_2v: eMMC HS400 mode(1.2V I/O) is supported
+- mmc-hs400-enhanced-strobe: eMMC HS400 enhanced strobe mode is supported
- dsr: Value the card's (optional) Driver Stage Register (DSR) should be
programmed with. Valid range: [0 .. 0xffff].
--
2.3.7
On Fri, 2016-04-29 at 10:48:34 +0800, Shawn Lin wrote:
> Currently sdhci-arasan 5.1 can support enhanced strobe function,
> and we now limit it just for "arasan,sdhci-5.1". Add
> mmc-hs400-enhanced-strobe in DT to enable the function if we'r sure
> our controller can support it.
>
> Signed-off-by: Shawn Lin <[email protected]>
> ---
>
> Changes in v2: None
>
> drivers/mmc/host/sdhci-of-arasan.c | 22 ++++++++++++++++++++++
> 1 file changed, 22 insertions(+)
>
> diff --git a/drivers/mmc/host/sdhci-of-arasan.c b/drivers/mmc/host/sdhci-of-arasan.c
> index 20b859e..a0e4536 100644
> --- a/drivers/mmc/host/sdhci-of-arasan.c
> +++ b/drivers/mmc/host/sdhci-of-arasan.c
> @@ -25,7 +25,9 @@
> #include "sdhci-pltfm.h"
>
> #define SDHCI_ARASAN_CLK_CTRL_OFFSET 0x2c
> +#define SDHCI_ARASAN_VENDOR_REGISTER 0x78
Just as a note: This register doesn't seem to exist in the IP version
Zynq is using. So, as long as we exclude that version from accessing it,
things should be fine (IIUC, that is the case).
Acked-by: Sören Brinkmann <[email protected]>
Sören