[PATCH 2/3] mmc: sdhci-pci: Add platform tuning callback for amd hs200 mode

[Wan Zongshun <vincent.wan@amd.com>]

From: Wan Zongshun <Vincent.Wan@amd.com>

AMD hs200 mode tuning mode is not compatible with standard tuning process,
so we need .platform_execute_tuning callback support in sdhci-pci-core.c,
this patch is to do:

1. Add platform_execute_tuning callback in sdhci_pci_slot.
2. Implement sdhci_pci_ops.platform_execute_tuning function.

Signed-off-by: Wan Zongshun <Vincent.Wan@amd.com>
---
Hi Ulf,

Though modifying sdhci_pci_ops to be not const that is easy to implement
my requirement, I am not sure it is right to do this.

So I just follow sdhci_pci_select_drive_strength style to add new callback:
sdhci_pci_platform_execute_tuning.

But I also met trouble in sdhci_execute_tuning of sdhci.c, I have to suppose
only sdhci_pci_platform_execute_tuning is returning -EPERM(current code,
my assumption is right), so that those vendor that has no
slot->platform_execute_tuning could be skipped and go next standard
tuning process.

If you have better idea for my requirement, please correct me.

Thanks!
Wan Zongshun.

---
 drivers/mmc/host/sdhci-pci-core.c | 23 +++++++++++++++++++++++
 drivers/mmc/host/sdhci-pci.h      |  1 +
 drivers/mmc/host/sdhci.c          |  3 ++-
 3 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/host/sdhci-pci-core.c b/drivers/mmc/host/sdhci-pci-core.c
index 01c5723..e7b2bbe 100644
--- a/drivers/mmc/host/sdhci-pci-core.c
+++ b/drivers/mmc/host/sdhci-pci-core.c
@@ -905,8 +905,19 @@ static int amd_probe(struct sdhci_pci_chip *chip)
 	return 0;
 }
 
+static int amd_probe_slot(struct sdhci_pci_slot *slot)
+{
+	struct sdhci_host *host = slot->host;
+
+	if (host->quirks2 & SDHCI_QUIRK2_CLEAR_TRANSFERMODE_REG_BEFORE_CMD)
+		slot->platform_execute_tuning = amd_execute_tuning;
+
+	return 0;
+}
+
 static const struct sdhci_pci_fixes sdhci_amd = {
 	.probe		= amd_probe,
+	.probe_slot	= amd_probe_slot,
 };
 
 static const struct pci_device_id pci_ids[] = {
@@ -1508,6 +1519,17 @@ static int sdhci_pci_select_drive_strength(struct sdhci_host *host,
 					   card_drv, drv_type);
 }
 
+static int sdhci_pci_platform_execute_tuning(struct sdhci_host *host,
+					     u32 opcode)
+{
+	struct sdhci_pci_slot *slot = sdhci_priv(host);
+
+	if (!slot->platform_execute_tuning)
+		return -EPERM;
+
+	return slot->platform_execute_tuning(host, opcode);
+}
+
 static const struct sdhci_ops sdhci_pci_ops = {
 	.set_clock	= sdhci_set_clock,
 	.enable_dma	= sdhci_pci_enable_dma,
@@ -1516,6 +1538,7 @@ static const struct sdhci_ops sdhci_pci_ops = {
 	.set_uhs_signaling = sdhci_set_uhs_signaling,
 	.hw_reset		= sdhci_pci_hw_reset,
 	.select_drive_strength	= sdhci_pci_select_drive_strength,
+	.platform_execute_tuning = sdhci_pci_platform_execute_tuning,
 };
 
 /*****************************************************************************\
diff --git a/drivers/mmc/host/sdhci-pci.h b/drivers/mmc/host/sdhci-pci.h
index d1a0b4d..48d98f1 100644
--- a/drivers/mmc/host/sdhci-pci.h
+++ b/drivers/mmc/host/sdhci-pci.h
@@ -83,6 +83,7 @@ struct sdhci_pci_slot {
 				     struct mmc_card *card,
 				     unsigned int max_dtr, int host_drv,
 				     int card_drv, int *drv_type);
+	int (*platform_execute_tuning)(struct sdhci_host *host, u32 opcode);
 };
 
 struct sdhci_pci_chip {
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 2753b722d..2a5a6ce 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -1937,7 +1937,8 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
 		spin_unlock_irqrestore(&host->lock, flags);
 		err = host->ops->platform_execute_tuning(host, opcode);
 		sdhci_runtime_pm_put(host);
-		return err;
+		if (err != EPERM)
+			return err;
 	}
 
 	ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
-- 
1.9.1