[PATCH v7 0/6] UHS-I SDR-104 support for sh_mobile_sdhi

[PATCH v7 0/6] UHS-I SDR-104 support for sh_mobile_sdhi

[Simon Horman]

Hi,

this series is based on work by Ai Kyuse to add UHS-I SDR-104 support for
sh_mobile_sdhi. It builds on work by Shinobu Uehara, Rob Taylor, William
Towle and Ian Molton, Ben Hutchings, Wolfram Sang and others to add UHS-I
SDR-50 support to the same driver.

It is based on a merge of the next branches of the mmc tree.

To aid review the following git branch is provided:
* https:://git.kernel.org/pub/scm/linux/kernel/git/horms/renesas.git topic/sdr104-driver-v7

Overview of changes since v6:
* Address review by Ulf
  - Detailed in per-patch changelogs
* Move integration (arm/arm64 dt) patches to separate patchset

Please see http://elinux.org/Tests:SD-SDHI-SDR104 for indicative tests
results.


Ai Kyuse (3):
  mmc: tmio: enhance illegal sequence handling
  mmc: tmio: Add hw reset support
  mmc: tmio: Add tuning support

Simon Horman (3):
  mmc: core: Add helper to see if a host can be retuned
  mmc: tmio: document mandatory and optional callbacks
  mmc: sh_mobile_sdhi: Add tuning support

 drivers/mmc/host/sh_mobile_sdhi.c | 265 +++++++++++++++++++++++++++++++++++++-
 drivers/mmc/host/tmio_mmc.h       |  18 ++-
 drivers/mmc/host/tmio_mmc_pio.c   |  87 ++++++++++++-
 include/linux/mmc/host.h          |   5 +
 4 files changed, 367 insertions(+), 8 deletions(-)

-- 
2.7.0.rc3.207.g0ac5344

[PATCH v7 1/6] mmc: core: Add helper to see if a host can be retuned

[Simon Horman]

This is in preparation for restoring saved tuning parameters
when resuming the TMIO driver.

Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
---
v6
* New patch
---
 include/linux/mmc/host.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index aa4bfbf129e4..4a9b4db8f22b 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -541,6 +541,11 @@ static inline void mmc_retune_recheck(struct mmc_host *host)
 		host->retune_now = 1;
 }
 
+static inline bool mmc_can_retune(struct mmc_host *host)
+{
+	return host->can_retune == 1;
+}
+
 void mmc_retune_pause(struct mmc_host *host);
 void mmc_retune_unpause(struct mmc_host *host);
 
-- 
2.7.0.rc3.207.g0ac5344

[PATCH v7 2/6] mmc: tmio: enhance illegal sequence handling

[Simon Horman]

From: Ai Kyuse <ai.kyuse.uw@renesas.com>

An illegal sequence command error may occur if there is a stopbit or
cmd_index error as well as a CRC error. The correct course of action
is to re-enable IRQs

An illegal sequence data error may occur if there is a CRC or stopbit
error,  or underrun. In this case set data->error correctly.

This is in preparation for enabling tuning support which relies on
differentiating between illegal sequence and other errors.

Signed-off-by: Ai Kyuse <ai.kyuse.uw@renesas.com>
[simon: broken out of a larger patch]
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
---
v4
* Added Ack from Wolfram Sang

v3
* No change

v2
* Broken out of a larger patch (but forgot to post)
---
 drivers/mmc/host/tmio_mmc_pio.c | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/drivers/mmc/host/tmio_mmc_pio.c b/drivers/mmc/host/tmio_mmc_pio.c
index 192817850dff..806308ac93e7 100644
--- a/drivers/mmc/host/tmio_mmc_pio.c
+++ b/drivers/mmc/host/tmio_mmc_pio.c
@@ -520,7 +520,7 @@ void tmio_mmc_do_data_irq(struct tmio_mmc_host *host)
 	schedule_work(&host->done);
 }
 
-static void tmio_mmc_data_irq(struct tmio_mmc_host *host)
+static void tmio_mmc_data_irq(struct tmio_mmc_host *host, unsigned int stat)
 {
 	struct mmc_data *data;
 	spin_lock(&host->lock);
@@ -529,6 +529,9 @@ static void tmio_mmc_data_irq(struct tmio_mmc_host *host)
 	if (!data)
 		goto out;
 
+	if (stat & TMIO_STAT_CRCFAIL || stat & TMIO_STAT_STOPBIT_ERR ||
+	    stat & TMIO_STAT_TXUNDERRUN)
+		data->error = -EILSEQ;
 	if (host->chan_tx && (data->flags & MMC_DATA_WRITE) && !host->force_pio) {
 		u32 status = sd_ctrl_read16_and_16_as_32(host, CTL_STATUS);
 		bool done = false;
@@ -577,8 +580,6 @@ static void tmio_mmc_cmd_irq(struct tmio_mmc_host *host,
 		goto out;
 	}
 
-	host->cmd = NULL;
-
 	/* This controller is sicker than the PXA one. Not only do we need to
 	 * drop the top 8 bits of the first response word, we also need to
 	 * modify the order of the response for short response command types.
@@ -598,14 +599,16 @@ static void tmio_mmc_cmd_irq(struct tmio_mmc_host *host,
 
 	if (stat & TMIO_STAT_CMDTIMEOUT)
 		cmd->error = -ETIMEDOUT;
-	else if (stat & TMIO_STAT_CRCFAIL && cmd->flags & MMC_RSP_CRC)
+	else if ((stat & TMIO_STAT_CRCFAIL && cmd->flags & MMC_RSP_CRC) ||
+		 stat & TMIO_STAT_STOPBIT_ERR ||
+		 stat & TMIO_STAT_CMD_IDX_ERR)
 		cmd->error = -EILSEQ;
 
 	/* If there is data to handle we enable data IRQs here, and
 	 * we will ultimatley finish the request in the data_end handler.
 	 * If theres no data or we encountered an error, finish now.
 	 */
-	if (host->data && !cmd->error) {
+	if (host->data && (!cmd->error || cmd->error == -EILSEQ)) {
 		if (host->data->flags & MMC_DATA_READ) {
 			if (host->force_pio || !host->chan_rx)
 				tmio_mmc_enable_mmc_irqs(host, TMIO_MASK_READOP);
@@ -666,7 +669,7 @@ static bool __tmio_mmc_sdcard_irq(struct tmio_mmc_host *host,
 	/* Data transfer completion */
 	if (ireg & TMIO_STAT_DATAEND) {
 		tmio_mmc_ack_mmc_irqs(host, TMIO_STAT_DATAEND);
-		tmio_mmc_data_irq(host);
+		tmio_mmc_data_irq(host, status);
 		return true;
 	}
 
-- 
2.7.0.rc3.207.g0ac5344

[PATCH v7 3/6] mmc: tmio: document mandatory and optional callbacks

[Simon Horman]

Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
---
v5
* New patch
---
 drivers/mmc/host/tmio_mmc.h | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/host/tmio_mmc.h b/drivers/mmc/host/tmio_mmc.h
index 1f1cb2628f67..4b36cb5c2d9c 100644
--- a/drivers/mmc/host/tmio_mmc.h
+++ b/drivers/mmc/host/tmio_mmc.h
@@ -151,8 +151,10 @@ struct tmio_mmc_host {
 	bool			native_hotplug;
 	bool			sdio_irq_enabled;
 
-	int (*write16_hook)(struct tmio_mmc_host *host, int addr);
+	/* Mandatory callback */
 	int (*clk_enable)(struct tmio_mmc_host *host);
+
+	/* Optional callbacks */
 	unsigned int (*clk_update)(struct tmio_mmc_host *host,
 				   unsigned int new_clock);
 	void (*clk_disable)(struct tmio_mmc_host *host);
@@ -161,6 +163,7 @@ struct tmio_mmc_host {
 	int (*card_busy)(struct mmc_host *mmc);
 	int (*start_signal_voltage_switch)(struct mmc_host *mmc,
 					   struct mmc_ios *ios);
+	int (*write16_hook)(struct tmio_mmc_host *host, int addr);
 };
 
 struct tmio_mmc_host *tmio_mmc_host_alloc(struct platform_device *pdev);
-- 
2.7.0.rc3.207.g0ac5344

[PATCH v7 4/6] mmc: tmio: Add hw reset support

[Simon Horman]

From: Ai Kyuse <ai.kyuse.uw@renesas.com>

Add hw reset support.

Signed-off-by: Ai Kyuse <ai.kyuse.uw@renesas.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
---
This is required by tuning support which will
be introduced by follow-up patches.

v6
* Rely on core to retune on reset

v5
* As suggested by Ulf Hansson
  - Broke out of a larger patch
---
 drivers/mmc/host/tmio_mmc.h     | 1 +
 drivers/mmc/host/tmio_mmc_pio.c | 9 +++++++++
 2 files changed, 10 insertions(+)

diff --git a/drivers/mmc/host/tmio_mmc.h b/drivers/mmc/host/tmio_mmc.h
index 4b36cb5c2d9c..4b71f31fba63 100644
--- a/drivers/mmc/host/tmio_mmc.h
+++ b/drivers/mmc/host/tmio_mmc.h
@@ -164,6 +164,7 @@ struct tmio_mmc_host {
 	int (*start_signal_voltage_switch)(struct mmc_host *mmc,
 					   struct mmc_ios *ios);
 	int (*write16_hook)(struct tmio_mmc_host *host, int addr);
+	void (*hw_reset)(struct tmio_mmc_host *host);
 };
 
 struct tmio_mmc_host *tmio_mmc_host_alloc(struct platform_device *pdev);
diff --git a/drivers/mmc/host/tmio_mmc_pio.c b/drivers/mmc/host/tmio_mmc_pio.c
index 806308ac93e7..f1d36f4533d2 100644
--- a/drivers/mmc/host/tmio_mmc_pio.c
+++ b/drivers/mmc/host/tmio_mmc_pio.c
@@ -756,6 +756,14 @@ static int tmio_mmc_start_data(struct tmio_mmc_host *host,
 	return 0;
 }
 
+static void tmio_mmc_hw_reset(struct mmc_host *mmc)
+{
+	struct tmio_mmc_host *host = mmc_priv(mmc);
+
+	if (host->hw_reset)
+		host->hw_reset(host);
+}
+
 /* Process requests from the MMC layer */
 static void tmio_mmc_request(struct mmc_host *mmc, struct mmc_request *mrq)
 {
@@ -970,6 +978,7 @@ static struct mmc_host_ops tmio_mmc_ops = {
 	.get_cd		= mmc_gpio_get_cd,
 	.enable_sdio_irq = tmio_mmc_enable_sdio_irq,
 	.multi_io_quirk	= tmio_multi_io_quirk,
+	.hw_reset	= tmio_mmc_hw_reset,
 };
 
 static int tmio_mmc_init_ocr(struct tmio_mmc_host *host)
-- 
2.7.0.rc3.207.g0ac5344

[PATCH v7 5/6] mmc: tmio: Add tuning support

[Simon Horman]

From: Ai Kyuse <ai.kyuse.uw@renesas.com>

Add tuning support for use with SDR104 mode

Signed-off-by: Ai Kyuse <ai.kyuse.uw@renesas.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
---
v7 [Simon Horman]
* As per review by Ulf Hansson:
  - Use tmio_mmc_hw_reset() rather than mmc_hw_reset() in
    tmio_mmc_execute_tuning()
  - Do not zero host->mmc->retune_period in tmio_mmc_execute_tuning()
  - Do not perform a reset if host->select_tuning() fails in
    tmio_mmc_host_runtime_resume() retuning should be
    performed if a request subsequently fails.
* Do not implicitly trigger retuning if host->check_scc_error() returns true

v6 [Simon Horman]
* As suggested by Ulf Hansson:
  - Restore saved tuning parameters on resume

v5 [Simon Horman]
* As suggested by Ulf Hansson:
  - Move hw reset support into a separate patch
  - Use more descriptive name for callback to check for SSC error
  - Rely on core to retune in case of -EILSEQ
  - Document mandatory and optional callbacks

v4 [Simon Horman]
* As suggested by Wolfram Sang:
  - Do not perform tuning if host->select_tuning is not set:
    it seems to make little sense to do so and moreover there is currently
    no such use-case
  - Do not add mrc->sbc handling from tmio_mmc_request,
    this is a hang-over from earlier versions of this patchset which
    did not use core infrastructure for retuning
  - Tidy up local variable usage
* Correct index passed to prepare_tuning(): this seems to have
  been the last piece of resolving the timeouts during tuning puzzle
* Further cleanups to tmio_mmc_execute_tuning():
  - Ensure tap is sized proportionally to its members
  - Remove stray '*' in comment
  - Use mmc rather than host->mmc, these are equivalent but
    the former seems tidier
  - Correct inverted logic in setting tap values
* Re-introduce retuning support. This was removed in v3.

v3 [Simon Horman]
* As suggested by Kuninori Morimoto:
  - Do not add unused retuning callback to struct tmio_mmc_host
  - Change return type of prepare_tuning callback to void
  - Add tap_size parameter to select_tuning callback

v2 [Simon Horman]
* As suggested by Kuninori Morimoto:
  - Actually remove unnecessary TMIO_MMC_HAS_UHS_SCC define
* As suggested by Wolfram Sang:
  - Rely on core to call tuning. This simplifies things somewhat.
  - Use mmc_send_tuning()
    - A side affect of this appears to be that we now see some recoverable
      errors logged during tuning. These are typically corrected by
      subsequent tuning. It is the logging that is the apparent side effect
      of this change.
      e.g.
      sh_mobile_sdhi ee100000.sd: timeout waiting for hardware interrupt (CMD19)
      sh_mobile_sdhi ee100000.sd: Tuning procedure failed
* Use bool rather than unsigned long to pass test status
  to select_tuning() callback
* Do not retune if init_tuning callback is not present or
  indicates that there are no taps present
* Retune on hardware reset

v1 [Simon Horman]
* Omit start_signal_voltage_switch and tmio_mmc_card_busy changes which are
  already present in mainline in a different form
* Return num from init_tuning rather than passing an extra parameter
  to hold the return value
* Only call host->init_tuning if it is non-NULL
* Place tmio_mmc_execute_tuning() such that no new forward declarations are
  required
* Remove unused TMIO_MMC_HAS_UHS_SCC define

v0 [Ai Kyuse]
---
 drivers/mmc/host/tmio_mmc.h     | 12 ++++++++
 drivers/mmc/host/tmio_mmc_pio.c | 63 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 75 insertions(+)

diff --git a/drivers/mmc/host/tmio_mmc.h b/drivers/mmc/host/tmio_mmc.h
index 4b71f31fba63..4b501f2d529f 100644
--- a/drivers/mmc/host/tmio_mmc.h
+++ b/drivers/mmc/host/tmio_mmc.h
@@ -150,6 +150,7 @@ struct tmio_mmc_host {
 	struct mutex		ios_lock;	/* protect set_ios() context */
 	bool			native_hotplug;
 	bool			sdio_irq_enabled;
+	u32			scc_tappos;
 
 	/* Mandatory callback */
 	int (*clk_enable)(struct tmio_mmc_host *host);
@@ -165,6 +166,17 @@ struct tmio_mmc_host {
 					   struct mmc_ios *ios);
 	int (*write16_hook)(struct tmio_mmc_host *host, int addr);
 	void (*hw_reset)(struct tmio_mmc_host *host);
+	void (*prepare_tuning)(struct tmio_mmc_host *host, unsigned long tap);
+	bool (*check_scc_error)(struct tmio_mmc_host *host);
+
+	/* Mandatory callback for tuning to occur which is
+	 * optional for SDR50 and mandatory for SDR104 */
+	unsigned int (*init_tuning)(struct tmio_mmc_host *host);
+	int (*select_tuning)(struct tmio_mmc_host *host);
+
+	/* Tuning values: 1 for success, 0 for failure */
+	DECLARE_BITMAP(taps, BITS_PER_BYTE * sizeof(long));
+	unsigned int tap_num;
 };
 
 struct tmio_mmc_host *tmio_mmc_host_alloc(struct platform_device *pdev);
diff --git a/drivers/mmc/host/tmio_mmc_pio.c b/drivers/mmc/host/tmio_mmc_pio.c
index f1d36f4533d2..46b5a456243b 100644
--- a/drivers/mmc/host/tmio_mmc_pio.c
+++ b/drivers/mmc/host/tmio_mmc_pio.c
@@ -36,6 +36,7 @@
 #include <linux/io.h>
 #include <linux/irq.h>
 #include <linux/mfd/tmio.h>
+#include <linux/mmc/card.h>
 #include <linux/mmc/host.h>
 #include <linux/mmc/mmc.h>
 #include <linux/mmc/slot-gpio.h>
@@ -298,6 +299,9 @@ static void tmio_mmc_finish_request(struct tmio_mmc_host *host)
 	if (mrq->cmd->error || (mrq->data && mrq->data->error))
 		tmio_mmc_abort_dma(host);
 
+	if (host->check_scc_error)
+		host->check_scc_error(host);
+
 	mmc_request_done(host->mmc, mrq);
 }
 
@@ -764,6 +768,56 @@ static void tmio_mmc_hw_reset(struct mmc_host *mmc)
 		host->hw_reset(host);
 }
 
+static int tmio_mmc_execute_tuning(struct mmc_host *mmc, u32 opcode)
+{
+	struct tmio_mmc_host *host = mmc_priv(mmc);
+	int i, ret = 0;
+
+	if (!host->tap_num) {
+		if (!host->init_tuning || !host->select_tuning)
+			/* Tuning is not supported */
+			goto out;
+
+		host->tap_num = host->init_tuning(host);
+		if (!host->tap_num)
+			/* Tuning is not supported */
+			goto out;
+	}
+
+	if (host->tap_num * 2 >= sizeof(host->taps) * BITS_PER_BYTE) {
+		dev_warn_once(&host->pdev->dev,
+		      "Too many taps, skipping tuning. Please consider "
+		      "updating size of taps field of tmio_mmc_host\n");
+		goto out;
+	}
+
+	bitmap_zero(host->taps, host->tap_num * 2);
+
+	/* Issue CMD19 twice for each tap */
+	for (i = 0; i < 2 * host->tap_num; i++) {
+		if (host->prepare_tuning)
+			host->prepare_tuning(host, i % host->tap_num);
+
+		ret = mmc_send_tuning(mmc, opcode, NULL);
+		if (ret && ret != -EILSEQ)
+			goto out;
+		if (ret == 0)
+			set_bit(i, host->taps);
+
+		mdelay(1);
+	}
+
+	ret = host->select_tuning(host);
+
+out:
+	if (ret < 0) {
+		dev_warn(&host->pdev->dev, "Tuning procedure failed\n");
+		tmio_mmc_hw_reset(mmc);
+	}
+
+	return ret;
+}
+
 /* Process requests from the MMC layer */
 static void tmio_mmc_request(struct mmc_host *mmc, struct mmc_request *mrq)
 {
@@ -979,6 +1033,7 @@ static struct mmc_host_ops tmio_mmc_ops = {
 	.enable_sdio_irq = tmio_mmc_enable_sdio_irq,
 	.multi_io_quirk	= tmio_multi_io_quirk,
 	.hw_reset	= tmio_mmc_hw_reset,
+	.execute_tuning = tmio_mmc_execute_tuning,
 };
 
 static int tmio_mmc_init_ocr(struct tmio_mmc_host *host)
@@ -1216,6 +1271,11 @@ int tmio_mmc_host_runtime_suspend(struct device *dev)
 }
 EXPORT_SYMBOL(tmio_mmc_host_runtime_suspend);
 
+static bool tmio_mmc_can_retune(struct tmio_mmc_host *host)
+{
+	return host->tap_num && mmc_can_retune(host->mmc);
+}
+
 int tmio_mmc_host_runtime_resume(struct device *dev)
 {
 	struct mmc_host *mmc = dev_get_drvdata(dev);
@@ -1229,6 +1289,9 @@ int tmio_mmc_host_runtime_resume(struct device *dev)
 
 	tmio_mmc_enable_dma(host, true);
 
+	if (tmio_mmc_can_retune(host) && host->select_tuning(host))
+		dev_warn(&host->pdev->dev, "Tuning selection failed\n");
+
 	return 0;
 }
 EXPORT_SYMBOL(tmio_mmc_host_runtime_resume);
-- 
2.7.0.rc3.207.g0ac5344

[PATCH v7 6/6] mmc: sh_mobile_sdhi: Add tuning support

[Simon Horman]

Add tuning support for use with SDR104 mode
This includes adding support for the sampling clock controller (SCC).

Based on work by Ai Kyuse.

Cc: Ai Kyuse <ai.kyuse.uw@renesas.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
---
v6 [Simon Horman]
* Rebase to use host->taps

v5 [Simon Horman]
* As suggested by Ulf Hansson
  - Use more descriptive name for callback to check for SSC error
* Correct return statement in sh_mobile_sdhi_hw_reset
* Reinstate Gen3 tuning support

v4 [Simon Horman]
As suggested by Geert Uytterhoeven:
* guard SDR104 specific portion of probe with host->mmc->caps &
  MMC_CAP_UHS_SDR104
* As suggested by Wolfram Sang:
  - Pass priv to sd_scc_{read,write}32 to save host_to_priv access
    for each call
  - Use 0x0 instead of other representations of 0 in hex
  - Use CLK_CTL_SCLKEN
  - Do not add unused SH_MOBILE_SDHI_MAX_TAP
  - Use ternary operator in sh_mobile_sdhi_select_tuning
  - Do include as yet unsupported HS200 in error string
* Reintroduce retuning support: This was removed in v3.
* Revert to algorithm in v1 patchset, on further reading of the documentation
  it appears to be correct.

v3 [Simon Horman]
* As suggested by Kuninori Morimoto:
  - Do not add unused retuning callback to struct tmio_mmc_host
  - Change return type of prepare_tuning callback to void
  - Add tap_size parameter to select_tuning callback

v2 [Simon Horman]
* As suggested by Kuninori Morimoto
  - Use host->mmc->caps & MMC_CAP_UHS_SDR104 instead of
    pdata->flags & TMIO_MMC_HAS_UHS_SCC to avoid needing the
    MMC_CAP_UHS_SDR104 flag at all.
    N.B: Morimoto-san suggested using but this flag is not actually
    set there in by current probe come.
  - Simplify logic in sh_mobile_sdhi_inquiry_tuning
* As suggested by Wolfram Sang
  - Use clk_rate instead of clk for field in struct sh_mobile_sdhi_scc
  - Remove inquiry_tuning callback which is now unnecessary as calling
    of tuning is handled by the core
  - Removed unused sh_mobile_sdhi_set_clk_div callback
  - Save sci_base address rather than calculating it on each read and write
* Update selection logic in sh_mobile_sdhi_select_tuning to match spec
* Use bool instead of long for taps parameter of
  sh_mobile_sdhi_select_tuning()
* Return 0 from sh_mobile_sdhi_init_tuning() if the
  SDR104 capability is not set and thus tuning should not
  be performed because it is not supported by the hardware

v1 [Simon Horman]
* Rebase
* Always use value of 0x8 for TAPNUM field of DTCNTL register
  rather than reading value from DT property. There does not
  seem to be a need to expose this in DT at this point.
* Do not include tmio_mmc_start_signal_voltage_switch changes which
  are already in mainline in a different form
* Do not add renesas,clk-rate property as the max-frequency property, which
  is now present in mainline, seems to provide the needed rate
* Omit Gen3 specific changes
* Do not provide renesas,mmc-scc-tappos DT property.
  Instead, always use taps provided in driver.
* Do not parse sd-uhs-sdr50 and sd-uhs-sdr104 properties.
  This is handled by the core.

v0 [Ai Kyuse]

Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
---
 drivers/mmc/host/sh_mobile_sdhi.c | 265 +++++++++++++++++++++++++++++++++++++-
 1 file changed, 264 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/host/sh_mobile_sdhi.c b/drivers/mmc/host/sh_mobile_sdhi.c
index 49edff7fee49..32d3e01e0840 100644
--- a/drivers/mmc/host/sh_mobile_sdhi.c
+++ b/drivers/mmc/host/sh_mobile_sdhi.c
@@ -47,6 +47,11 @@
 
 #define host_to_priv(host) container_of((host)->pdata, struct sh_mobile_sdhi, mmc_data)
 
+struct sh_mobile_sdhi_scc {
+	unsigned long clk_rate;	/* clock rate for SDR104 */
+	u32 tap;		/* sampling clock position for SDR104 */
+};
+
 struct sh_mobile_sdhi_of_data {
 	unsigned long tmio_flags;
 	unsigned long capabilities;
@@ -54,6 +59,9 @@ struct sh_mobile_sdhi_of_data {
 	enum dma_slave_buswidth dma_buswidth;
 	dma_addr_t dma_rx_offset;
 	unsigned bus_shift;
+	int scc_offset;
+	struct sh_mobile_sdhi_scc *taps;
+	int taps_num;
 };
 
 static const struct sh_mobile_sdhi_of_data of_default_cfg = {
@@ -66,12 +74,35 @@ static const struct sh_mobile_sdhi_of_data of_rcar_gen1_compatible = {
 	.capabilities	= MMC_CAP_SD_HIGHSPEED | MMC_CAP_SDIO_IRQ,
 };
 
+/* Definitions for sampling clocks */
+static struct sh_mobile_sdhi_scc rcar_gen2_scc_taps[] = {
+	{
+		.clk_rate = 156000000,
+		.tap = 0x00000703,
+	},
+	{
+		.clk_rate = 0,
+		.tap = 0x00000300,
+	},
+};
+
 static const struct sh_mobile_sdhi_of_data of_rcar_gen2_compatible = {
 	.tmio_flags	= TMIO_MMC_HAS_IDLE_WAIT | TMIO_MMC_WRPROTECT_DISABLE |
 			  TMIO_MMC_CLK_ACTUAL | TMIO_MMC_MIN_RCAR2,
 	.capabilities	= MMC_CAP_SD_HIGHSPEED | MMC_CAP_SDIO_IRQ,
 	.dma_buswidth	= DMA_SLAVE_BUSWIDTH_4_BYTES,
 	.dma_rx_offset	= 0x2000,
+	.scc_offset	= 0x0300,
+	.taps		= rcar_gen2_scc_taps,
+	.taps_num	= ARRAY_SIZE(rcar_gen2_scc_taps),
+};
+
+/* Definitions for sampling clocks */
+static struct sh_mobile_sdhi_scc rcar_gen3_scc_taps[] = {
+	{
+		.clk_rate = 0,
+		.tap = 0x00000300,
+	},
 };
 
 static const struct sh_mobile_sdhi_of_data of_rcar_gen3_compatible = {
@@ -79,6 +110,9 @@ static const struct sh_mobile_sdhi_of_data of_rcar_gen3_compatible = {
 			  TMIO_MMC_CLK_ACTUAL | TMIO_MMC_MIN_RCAR2,
 	.capabilities	= MMC_CAP_SD_HIGHSPEED | MMC_CAP_SDIO_IRQ,
 	.bus_shift	= 2,
+	.scc_offset	= 0x1000,
+	.taps		= rcar_gen3_scc_taps,
+	.taps_num	= ARRAY_SIZE(rcar_gen3_scc_taps),
 };
 
 static const struct of_device_id sh_mobile_sdhi_of_match[] = {
@@ -105,6 +139,7 @@ struct sh_mobile_sdhi {
 	struct tmio_mmc_dma dma_priv;
 	struct pinctrl *pinctrl;
 	struct pinctrl_state *pins_default, *pins_uhs;
+	void __iomem *scc_ctl;
 };
 
 static void sh_mobile_sdhi_sdbuf_width(struct tmio_mmc_host *host, int width)
@@ -255,6 +290,201 @@ static int sh_mobile_sdhi_start_signal_voltage_switch(struct mmc_host *mmc,
 	return pinctrl_select_state(priv->pinctrl, pin_state);
 }
 
+/* SCC registers */
+#define SH_MOBILE_SDHI_SCC_DTCNTL	0x000
+#define SH_MOBILE_SDHI_SCC_TAPSET	0x002
+#define SH_MOBILE_SDHI_SCC_DT2FF	0x004
+#define SH_MOBILE_SDHI_SCC_CKSEL	0x006
+#define SH_MOBILE_SDHI_SCC_RVSCNTL	0x008
+#define SH_MOBILE_SDHI_SCC_RVSREQ	0x00A
+
+/* Definitions for values the SH_MOBILE_SDHI_SCC_DTCNTL register */
+#define SH_MOBILE_SDHI_SCC_DTCNTL_TAPEN		BIT(0)
+#define SH_MOBILE_SDHI_SCC_DTCNTL_TAPNUM_SHIFT	16
+#define SH_MOBILE_SDHI_SCC_DTCNTL_TAPNUM_MASK	0xff
+
+/* Definitions for values the SH_MOBILE_SDHI_SCC_CKSEL register */
+#define SH_MOBILE_SDHI_SCC_CKSEL_DTSEL		BIT(0)
+/* Definitions for values the SH_MOBILE_SDHI_SCC_RVSCNTL register */
+#define SH_MOBILE_SDHI_SCC_RVSCNTL_RVSEN	BIT(1)
+/* Definitions for values the SH_MOBILE_SDHI_SCC_RVSREQ register */
+#define SH_MOBILE_SDHI_SCC_RVSREQ_RVSERR	BIT(2)
+
+static inline u32 sd_scc_read32(struct tmio_mmc_host *host,
+				struct sh_mobile_sdhi *priv, int addr)
+{
+	return readl(priv->scc_ctl + (addr << host->bus_shift));
+}
+
+static inline void sd_scc_write32(struct tmio_mmc_host *host,
+				  struct sh_mobile_sdhi *priv,
+				  int addr, u32 val)
+{
+	writel(val, priv->scc_ctl + (addr << host->bus_shift));
+}
+
+static unsigned int sh_mobile_sdhi_init_tuning(struct tmio_mmc_host *host)
+{
+	struct sh_mobile_sdhi *priv;
+
+	if (!(host->mmc->caps & MMC_CAP_UHS_SDR104))
+		return 0;
+
+	priv = host_to_priv(host);
+
+	/* set sampling clock selection range */
+	sd_scc_write32(host, priv, SH_MOBILE_SDHI_SCC_DTCNTL,
+		       0x8 << SH_MOBILE_SDHI_SCC_DTCNTL_TAPNUM_SHIFT);
+
+	/* Initialize SCC */
+	sd_ctrl_write32_as_16_and_16(host, CTL_STATUS, 0x0);
+
+	sd_scc_write32(host, priv, SH_MOBILE_SDHI_SCC_DTCNTL,
+		       SH_MOBILE_SDHI_SCC_DTCNTL_TAPEN |
+		       sd_scc_read32(host, priv, SH_MOBILE_SDHI_SCC_DTCNTL));
+
+	sd_ctrl_write16(host, CTL_SD_CARD_CLK_CTL, ~CLK_CTL_SCLKEN &
+			sd_ctrl_read16(host, CTL_SD_CARD_CLK_CTL));
+
+	sd_scc_write32(host, priv, SH_MOBILE_SDHI_SCC_CKSEL,
+		       SH_MOBILE_SDHI_SCC_CKSEL_DTSEL |
+		       sd_scc_read32(host, priv, SH_MOBILE_SDHI_SCC_CKSEL));
+
+	sd_ctrl_write16(host, CTL_SD_CARD_CLK_CTL, CLK_CTL_SCLKEN |
+			sd_ctrl_read16(host, CTL_SD_CARD_CLK_CTL));
+
+	sd_scc_write32(host, priv, SH_MOBILE_SDHI_SCC_RVSCNTL,
+		       ~SH_MOBILE_SDHI_SCC_RVSCNTL_RVSEN &
+		       sd_scc_read32(host, priv, SH_MOBILE_SDHI_SCC_RVSCNTL));
+
+	sd_scc_write32(host, priv, SH_MOBILE_SDHI_SCC_DT2FF, host->scc_tappos);
+
+	/* Read TAPNUM */
+	return (sd_scc_read32(host, priv, SH_MOBILE_SDHI_SCC_DTCNTL) >>
+		SH_MOBILE_SDHI_SCC_DTCNTL_TAPNUM_SHIFT) &
+		SH_MOBILE_SDHI_SCC_DTCNTL_TAPNUM_MASK;
+}
+
+static void sh_mobile_sdhi_prepare_tuning(struct tmio_mmc_host *host,
+					 unsigned long tap)
+{
+	struct sh_mobile_sdhi *priv = host_to_priv(host);
+
+	/* Set sampling clock position */
+	sd_scc_write32(host, priv, SH_MOBILE_SDHI_SCC_TAPSET, tap);
+}
+
+#define SH_MOBILE_SDHI_MAX_TAP 3
+
+static int sh_mobile_sdhi_select_tuning(struct tmio_mmc_host *host)
+{
+	struct sh_mobile_sdhi *priv = host_to_priv(host);
+	unsigned long tap_cnt;  /* counter of tuning success */
+	unsigned long tap_set;  /* tap position */
+	unsigned long tap_start;/* start position of tuning success */
+	unsigned long tap_end;  /* end position of tuning success */
+	unsigned long ntap;     /* temporary counter of tuning success */
+	unsigned long i;
+
+	/* Clear SCC_RVSREQ */
+	sd_scc_write32(host, priv, SH_MOBILE_SDHI_SCC_RVSREQ, 0);
+
+	/*
+	 * Find the longest consecutive run of successful probes.  If that
+	 * is more than SH_MOBILE_SDHI_MAX_TAP probes long then use the
+	 * center index as the tap.
+	 */
+	tap_cnt = 0;
+	ntap = 0;
+	tap_start = 0;
+	tap_end = 0;
+	for (i = 0; i < host->tap_num * 2; i++) {
+		if (test_bit(i, host->taps))
+			ntap++;
+		else {
+			if (ntap > tap_cnt) {
+				tap_start = i - ntap;
+				tap_end = i - 1;
+				tap_cnt = ntap;
+			}
+			ntap = 0;
+		}
+	}
+
+	if (ntap > tap_cnt) {
+		tap_start = i - ntap;
+		tap_end = i - 1;
+		tap_cnt = ntap;
+	}
+
+	if (tap_cnt >= SH_MOBILE_SDHI_MAX_TAP)
+		tap_set = (tap_start + tap_end) / 2 % host->tap_num;
+	else
+		return -EIO;
+
+	/* Set SCC */
+	sd_scc_write32(host, priv, SH_MOBILE_SDHI_SCC_TAPSET, tap_set);
+
+	/* Enable auto re-tuning */
+	sd_scc_write32(host, priv, SH_MOBILE_SDHI_SCC_RVSCNTL,
+		       SH_MOBILE_SDHI_SCC_RVSCNTL_RVSEN |
+		       sd_scc_read32(host, priv, SH_MOBILE_SDHI_SCC_RVSCNTL));
+
+	return 0;
+}
+
+
+static bool sh_mobile_sdhi_check_scc_error(struct tmio_mmc_host *host)
+{
+	struct sh_mobile_sdhi *priv;
+
+	if (!(host->mmc->caps & MMC_CAP_UHS_SDR104))
+		return 0;
+
+	priv = host_to_priv(host);
+
+	/* Check SCC error */
+	if (sd_scc_read32(host, priv, SH_MOBILE_SDHI_SCC_RVSCNTL) &
+	    SH_MOBILE_SDHI_SCC_RVSCNTL_RVSEN &&
+	    sd_scc_read32(host, priv, SH_MOBILE_SDHI_SCC_RVSREQ) &
+	    SH_MOBILE_SDHI_SCC_RVSREQ_RVSERR) {
+		/* Clear SCC error */
+		sd_scc_write32(host, priv, SH_MOBILE_SDHI_SCC_RVSREQ, 0);
+		return true;
+	}
+
+	return false;
+}
+
+static void sh_mobile_sdhi_hw_reset(struct tmio_mmc_host *host)
+{
+	struct sh_mobile_sdhi *priv;
+
+	if (host->mmc->caps & MMC_CAP_UHS_SDR104)
+		return;
+
+	priv = host_to_priv(host);
+
+	/* Reset SCC */
+	sd_ctrl_write16(host, CTL_SD_CARD_CLK_CTL, ~CLK_CTL_SCLKEN &
+			sd_ctrl_read16(host, CTL_SD_CARD_CLK_CTL));
+
+	sd_scc_write32(host, priv, SH_MOBILE_SDHI_SCC_CKSEL,
+		       ~SH_MOBILE_SDHI_SCC_CKSEL_DTSEL &
+		       sd_scc_read32(host, priv, SH_MOBILE_SDHI_SCC_CKSEL));
+
+	sd_ctrl_write16(host, CTL_SD_CARD_CLK_CTL, CLK_CTL_SCLKEN |
+			sd_ctrl_read16(host, CTL_SD_CARD_CLK_CTL));
+
+	sd_scc_write32(host, priv, SH_MOBILE_SDHI_SCC_RVSCNTL,
+		       ~SH_MOBILE_SDHI_SCC_RVSCNTL_RVSEN &
+		       sd_scc_read32(host, priv, SH_MOBILE_SDHI_SCC_RVSCNTL));
+
+	sd_scc_write32(host, priv, SH_MOBILE_SDHI_SCC_RVSCNTL,
+		       ~SH_MOBILE_SDHI_SCC_RVSCNTL_RVSEN &
+		       sd_scc_read32(host, priv, SH_MOBILE_SDHI_SCC_RVSCNTL));
+}
+
 static int sh_mobile_sdhi_wait_idle(struct tmio_mmc_host *host)
 {
 	int timeout = 1000;
@@ -325,7 +555,7 @@ static int sh_mobile_sdhi_probe(struct platform_device *pdev)
 	struct tmio_mmc_data *mmd = pdev->dev.platform_data;
 	struct tmio_mmc_host *host;
 	struct resource *res;
-	int irq, ret, i = 0;
+	int irq, ret, i;
 	struct tmio_mmc_dma *dma_priv;
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
@@ -384,6 +614,11 @@ static int sh_mobile_sdhi_probe(struct platform_device *pdev)
 		host->card_busy	= sh_mobile_sdhi_card_busy;
 		host->start_signal_voltage_switch =
 			sh_mobile_sdhi_start_signal_voltage_switch;
+		host->init_tuning	= sh_mobile_sdhi_init_tuning;
+		host->prepare_tuning	= sh_mobile_sdhi_prepare_tuning;
+		host->select_tuning	= sh_mobile_sdhi_select_tuning;
+		host->check_scc_error	= sh_mobile_sdhi_check_scc_error;
+		host->hw_reset		= sh_mobile_sdhi_hw_reset;
 	}
 
 	/* Orginally registers were 16 bit apart, could be 32 or 64 nowadays */
@@ -424,6 +659,34 @@ static int sh_mobile_sdhi_probe(struct platform_device *pdev)
 	if (ret < 0)
 		goto efree;
 
+	if (host->mmc->caps & MMC_CAP_UHS_SDR104) {
+		host->mmc->caps |= MMC_CAP_HW_RESET;
+
+		if (of_id && of_id->data) {
+			const struct sh_mobile_sdhi_of_data *of_data;
+			const struct sh_mobile_sdhi_scc *taps;
+			bool hit = false;
+
+			of_data = of_id->data;
+			taps = of_data->taps;
+
+			for (i = 0; i < of_data->taps_num; i++) {
+				if (taps[i].clk_rate == 0 ||
+				    taps[i].clk_rate == host->mmc->f_max) {
+					host->scc_tappos = taps->tap;
+					hit = true;
+					break;
+				}
+			}
+
+			if (!hit)
+				dev_warn(&host->pdev->dev, "Unknown clock rate for SDR104\n");
+
+			priv->scc_ctl = host->ctl + of_data->scc_offset;
+		}
+	}
+
+	i = 0;
 	while (1) {
 		irq = platform_get_irq(pdev, i);
 		if (irq < 0)
-- 
2.7.0.rc3.207.g0ac5344

Re: [PATCH v7 6/6] mmc: sh_mobile_sdhi: Add tuning support

[Simon Horman]

On Tue, Sep 13, 2016 at 12:56:15PM +0200, Simon Horman wrote:
> Add tuning support for use with SDR104 mode
> This includes adding support for the sampling clock controller (SCC).
> 
> Based on work by Ai Kyuse.
> 
> Cc: Ai Kyuse <ai.kyuse.uw@renesas.com>
> Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

...

> Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
> ---
>  drivers/mmc/host/sh_mobile_sdhi.c | 265 +++++++++++++++++++++++++++++++++++++-
>  1 file changed, 264 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/mmc/host/sh_mobile_sdhi.c b/drivers/mmc/host/sh_mobile_sdhi.c
> index 49edff7fee49..32d3e01e0840 100644
> --- a/drivers/mmc/host/sh_mobile_sdhi.c
> +++ b/drivers/mmc/host/sh_mobile_sdhi.c


...

> +static void sh_mobile_sdhi_hw_reset(struct tmio_mmc_host *host)
> +{
> +	struct sh_mobile_sdhi *priv;
> +
> +	if (host->mmc->caps & MMC_CAP_UHS_SDR104)
> +		return;

The logic above is inverted, it should be:

	if (!(host->mmc->caps & MMC_CAP_UHS_SDR104))
		return;

An observable side effect of the above is that on the r8a7796/Salvator-X
a card is not detected after being ejected and re-inserted.

Re: [PATCH v7 0/6] UHS-I SDR-104 support for sh_mobile_sdhi

[Ulf Hansson]

On 13 September 2016 at 12:56, Simon Horman <horms+renesas@verge.net.au> wrote:
>
> Hi,
>
> this series is based on work by Ai Kyuse to add UHS-I SDR-104 support for
> sh_mobile_sdhi. It builds on work by Shinobu Uehara, Rob Taylor, William
> Towle and Ian Molton, Ben Hutchings, Wolfram Sang and others to add UHS-I
> SDR-50 support to the same driver.
>
> It is based on a merge of the next branches of the mmc tree.
>
> To aid review the following git branch is provided:
> * https:://git.kernel.org/pub/scm/linux/kernel/git/horms/renesas.git topic/sdr104-driver-v7
>
> Overview of changes since v6:
> * Address review by Ulf
>   - Detailed in per-patch changelogs
> * Move integration (arm/arm64 dt) patches to separate patchset
>
> Please see http://elinux.org/Tests:SD-SDHI-SDR104 for indicative tests
> results.
>
>
> Ai Kyuse (3):
>   mmc: tmio: enhance illegal sequence handling
>   mmc: tmio: Add hw reset support
>   mmc: tmio: Add tuning support
>
> Simon Horman (3):
>   mmc: core: Add helper to see if a host can be retuned
>   mmc: tmio: document mandatory and optional callbacks
>   mmc: sh_mobile_sdhi: Add tuning support
>
>  drivers/mmc/host/sh_mobile_sdhi.c | 265 +++++++++++++++++++++++++++++++++++++-
>  drivers/mmc/host/tmio_mmc.h       |  18 ++-
>  drivers/mmc/host/tmio_mmc_pio.c   |  87 ++++++++++++-
>  include/linux/mmc/host.h          |   5 +
>  4 files changed, 367 insertions(+), 8 deletions(-)
>
> --
> 2.7.0.rc3.207.g0ac5344
>

This looks good to me, although I would like to get an ack from
Wolfram before I queue this up.

Kind regards
Uffe

Re: [PATCH v7 0/6] UHS-I SDR-104 support for sh_mobile_sdhi

[Wolfram Sang]

[-- Attachment #1: Type: text/plain, Size: 1844 bytes --]

On Tue, Sep 13, 2016 at 02:48:26PM +0200, Ulf Hansson wrote:
> On 13 September 2016 at 12:56, Simon Horman <horms+renesas@verge.net.au> wrote:
> >
> > Hi,
> >
> > this series is based on work by Ai Kyuse to add UHS-I SDR-104 support for
> > sh_mobile_sdhi. It builds on work by Shinobu Uehara, Rob Taylor, William
> > Towle and Ian Molton, Ben Hutchings, Wolfram Sang and others to add UHS-I
> > SDR-50 support to the same driver.
> >
> > It is based on a merge of the next branches of the mmc tree.
> >
> > To aid review the following git branch is provided:
> > * https:://git.kernel.org/pub/scm/linux/kernel/git/horms/renesas.git topic/sdr104-driver-v7
> >
> > Overview of changes since v6:
> > * Address review by Ulf
> >   - Detailed in per-patch changelogs
> > * Move integration (arm/arm64 dt) patches to separate patchset
> >
> > Please see http://elinux.org/Tests:SD-SDHI-SDR104 for indicative tests
> > results.
> >
> >
> > Ai Kyuse (3):
> >   mmc: tmio: enhance illegal sequence handling
> >   mmc: tmio: Add hw reset support
> >   mmc: tmio: Add tuning support
> >
> > Simon Horman (3):
> >   mmc: core: Add helper to see if a host can be retuned
> >   mmc: tmio: document mandatory and optional callbacks
> >   mmc: sh_mobile_sdhi: Add tuning support
> >
> >  drivers/mmc/host/sh_mobile_sdhi.c | 265 +++++++++++++++++++++++++++++++++++++-
> >  drivers/mmc/host/tmio_mmc.h       |  18 ++-
> >  drivers/mmc/host/tmio_mmc_pio.c   |  87 ++++++++++++-
> >  include/linux/mmc/host.h          |   5 +
> >  4 files changed, 367 insertions(+), 8 deletions(-)
> >
> > --
> > 2.7.0.rc3.207.g0ac5344
> >
> 
> This looks good to me, although I would like to get an ack from
> Wolfram before I queue this up.

I'll test today or tomorrow. Same for the r7s72100 patches.

Thanks,

   Wolfram


[-- Attachment #2: signature.asc --]
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Re: [PATCH v7 0/6] UHS-I SDR-104 support for sh_mobile_sdhi

[Simon Horman]

On Tue, Sep 13, 2016 at 02:58:25PM +0200, Wolfram Sang wrote:
> On Tue, Sep 13, 2016 at 02:48:26PM +0200, Ulf Hansson wrote:
> > On 13 September 2016 at 12:56, Simon Horman <horms+renesas@verge.net.au> wrote:
> > >
> > > Hi,
> > >
> > > this series is based on work by Ai Kyuse to add UHS-I SDR-104 support for
> > > sh_mobile_sdhi. It builds on work by Shinobu Uehara, Rob Taylor, William
> > > Towle and Ian Molton, Ben Hutchings, Wolfram Sang and others to add UHS-I
> > > SDR-50 support to the same driver.
> > >
> > > It is based on a merge of the next branches of the mmc tree.
> > >
> > > To aid review the following git branch is provided:
> > > * https:://git.kernel.org/pub/scm/linux/kernel/git/horms/renesas.git topic/sdr104-driver-v7
> > >
> > > Overview of changes since v6:
> > > * Address review by Ulf
> > >   - Detailed in per-patch changelogs
> > > * Move integration (arm/arm64 dt) patches to separate patchset
> > >
> > > Please see http://elinux.org/Tests:SD-SDHI-SDR104 for indicative tests
> > > results.
> > >
> > >
> > > Ai Kyuse (3):
> > >   mmc: tmio: enhance illegal sequence handling
> > >   mmc: tmio: Add hw reset support
> > >   mmc: tmio: Add tuning support
> > >
> > > Simon Horman (3):
> > >   mmc: core: Add helper to see if a host can be retuned
> > >   mmc: tmio: document mandatory and optional callbacks
> > >   mmc: sh_mobile_sdhi: Add tuning support
> > >
> > >  drivers/mmc/host/sh_mobile_sdhi.c | 265 +++++++++++++++++++++++++++++++++++++-
> > >  drivers/mmc/host/tmio_mmc.h       |  18 ++-
> > >  drivers/mmc/host/tmio_mmc_pio.c   |  87 ++++++++++++-
> > >  include/linux/mmc/host.h          |   5 +
> > >  4 files changed, 367 insertions(+), 8 deletions(-)
> > >
> > > --
> > > 2.7.0.rc3.207.g0ac5344
> > >
> > 
> > This looks good to me, although I would like to get an ack from
> > Wolfram before I queue this up.
> 
> I'll test today or tomorrow. Same for the r7s72100 patches.

Thanks!

I found a logic error in the last patch of the series,
I proposed a fix in a sub-thread for that patch.

If you could use my proposed one-line fix when testing that would be great.

Re: [PATCH v7 0/6] UHS-I SDR-104 support for sh_mobile_sdhi

[Wolfram Sang]

[-- Attachment #1: Type: text/plain, Size: 2505 bytes --]

On Tue, Sep 13, 2016 at 02:48:26PM +0200, Ulf Hansson wrote:
> On 13 September 2016 at 12:56, Simon Horman <horms+renesas@verge.net.au> wrote:
> >
> > Hi,
> >
> > this series is based on work by Ai Kyuse to add UHS-I SDR-104 support for
> > sh_mobile_sdhi. It builds on work by Shinobu Uehara, Rob Taylor, William
> > Towle and Ian Molton, Ben Hutchings, Wolfram Sang and others to add UHS-I
> > SDR-50 support to the same driver.
> >
> > It is based on a merge of the next branches of the mmc tree.
> >
> > To aid review the following git branch is provided:
> > * https:://git.kernel.org/pub/scm/linux/kernel/git/horms/renesas.git topic/sdr104-driver-v7
> >
> > Overview of changes since v6:
> > * Address review by Ulf
> >   - Detailed in per-patch changelogs
> > * Move integration (arm/arm64 dt) patches to separate patchset
> >
> > Please see http://elinux.org/Tests:SD-SDHI-SDR104 for indicative tests
> > results.
> >
> >
> > Ai Kyuse (3):
> >   mmc: tmio: enhance illegal sequence handling
> >   mmc: tmio: Add hw reset support
> >   mmc: tmio: Add tuning support
> >
> > Simon Horman (3):
> >   mmc: core: Add helper to see if a host can be retuned
> >   mmc: tmio: document mandatory and optional callbacks
> >   mmc: sh_mobile_sdhi: Add tuning support
> >
> >  drivers/mmc/host/sh_mobile_sdhi.c | 265 +++++++++++++++++++++++++++++++++++++-
> >  drivers/mmc/host/tmio_mmc.h       |  18 ++-
> >  drivers/mmc/host/tmio_mmc_pio.c   |  87 ++++++++++++-
> >  include/linux/mmc/host.h          |   5 +
> >  4 files changed, 367 insertions(+), 8 deletions(-)
> >
> > --
> > 2.7.0.rc3.207.g0ac5344
> >
> 
> This looks good to me, although I would like to get an ack from
> Wolfram before I queue this up.

So, I did test this on my M3-W Salvator-X (with the fixup patch
Simon sent on top of this series):

+ My SanDisk card always gets properly tuned; re-inserting works

+ My Samsung card gets properly tuned if it is the first card
  inserted to a slot.

- The Samsung card does not get tuned when it was not the first card in
  a slot, i.e. it was re-inserted or the SanDisk card had been used in
  that slot before:

[   56.799203] mmc2: tuning execution failed: -5
[   56.803565] mmc2: error -5 whilst initialising SD card

Note that if I re-insert the SanDisk card to this slot, it will be tuned
correctly. Just the Samsung card will continue to fail.

Any pointers? Maybe some more re-initialization?

Regards,

   Wolfram


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