* [PATCH v2] mmc: tegra: Write xfer_mode, CMD regs in together
@ 2015-01-28 16:45 Rhyland Klein
2015-01-29 10:24 ` Ulf Hansson
0 siblings, 1 reply; 2+ messages in thread
From: Rhyland Klein @ 2015-01-28 16:45 UTC (permalink / raw)
To: ulf.hansson, chris
Cc: swarren, thierry.reding, linux-tegra, linux-kernel, pkunapuli,
linux-mmc, gnurou, Rhyland Klein
From: Pavan Kunapuli <pkunapuli@nvidia.com>
If there is a gap between xfer mode and command register writes,
tegra SDMMC controller can sometimes issue a spurious command before
the CMD register is written. To avoid this, these two registers need
to be written together in a single write operation.
This is implemented as an NVQUIRK as it applies to T114, T124 and
T132.
Signed-off-by: Pavan Kunapuli <pkunapuli@nvidia.com>
Signed-off-by: Rhyland Klein <rklein@nvidia.com>
---
v2:
- Fixed quirk flag check s/*/&
- Removed line clearing xfer_mode_shadow
- Added explicit mention of which platforms this applies to in
description
drivers/mmc/host/sdhci-tegra.c | 30 +++++++++++++++++++++++++++++-
1 file changed, 29 insertions(+), 1 deletion(-)
diff --git a/drivers/mmc/host/sdhci-tegra.c b/drivers/mmc/host/sdhci-tegra.c
index 59797106af93..f3778d58d1cd 100644
--- a/drivers/mmc/host/sdhci-tegra.c
+++ b/drivers/mmc/host/sdhci-tegra.c
@@ -41,6 +41,7 @@
#define NVQUIRK_DISABLE_SDR50 BIT(3)
#define NVQUIRK_DISABLE_SDR104 BIT(4)
#define NVQUIRK_DISABLE_DDR50 BIT(5)
+#define NVQUIRK_SHADOW_XFER_MODE_REG BIT(6)
struct sdhci_tegra_soc_data {
const struct sdhci_pltfm_data *pdata;
@@ -67,6 +68,31 @@ static u16 tegra_sdhci_readw(struct sdhci_host *host, int reg)
return readw(host->ioaddr + reg);
}
+static void tegra_sdhci_writew(struct sdhci_host *host, u16 val, int reg)
+{
+ struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+ struct sdhci_tegra *tegra_host = pltfm_host->priv;
+ const struct sdhci_tegra_soc_data *soc_data = tegra_host->soc_data;
+
+ if (soc_data->nvquirks & NVQUIRK_SHADOW_XFER_MODE_REG) {
+ switch (reg) {
+ case SDHCI_TRANSFER_MODE:
+ /*
+ * Postpone this write, we must do it together with a
+ * command write that is down below.
+ */
+ pltfm_host->xfer_mode_shadow = val;
+ return;
+ case SDHCI_COMMAND:
+ writel((val << 16) | pltfm_host->xfer_mode_shadow,
+ host->ioaddr + SDHCI_TRANSFER_MODE);
+ return;
+ }
+ }
+
+ writew(val, host->ioaddr + reg);
+}
+
static void tegra_sdhci_writel(struct sdhci_host *host, u32 val, int reg)
{
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
@@ -147,6 +173,7 @@ static void tegra_sdhci_set_bus_width(struct sdhci_host *host, int bus_width)
static const struct sdhci_ops tegra_sdhci_ops = {
.get_ro = tegra_sdhci_get_ro,
.read_w = tegra_sdhci_readw,
+ .write_w = tegra_sdhci_writew,
.write_l = tegra_sdhci_writel,
.set_clock = sdhci_set_clock,
.set_bus_width = tegra_sdhci_set_bus_width,
@@ -201,7 +228,8 @@ static struct sdhci_tegra_soc_data soc_data_tegra114 = {
.pdata = &sdhci_tegra114_pdata,
.nvquirks = NVQUIRK_DISABLE_SDR50 |
NVQUIRK_DISABLE_DDR50 |
- NVQUIRK_DISABLE_SDR104,
+ NVQUIRK_DISABLE_SDR104 |
+ NVQUIRK_SHADOW_XFER_MODE_REG,
};
static const struct of_device_id sdhci_tegra_dt_match[] = {
--
1.7.9.5
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH v2] mmc: tegra: Write xfer_mode, CMD regs in together
2015-01-28 16:45 [PATCH v2] mmc: tegra: Write xfer_mode, CMD regs in together Rhyland Klein
@ 2015-01-29 10:24 ` Ulf Hansson
0 siblings, 0 replies; 2+ messages in thread
From: Ulf Hansson @ 2015-01-29 10:24 UTC (permalink / raw)
To: Rhyland Klein
Cc: Chris Ball, Stephen Warren, Thierry Reding, linux-tegra,
linux-kernel, pkunapuli, linux-mmc, Alexandre Courbot
On 28 January 2015 at 17:45, Rhyland Klein <rklein@nvidia.com> wrote:
> From: Pavan Kunapuli <pkunapuli@nvidia.com>
>
> If there is a gap between xfer mode and command register writes,
> tegra SDMMC controller can sometimes issue a spurious command before
> the CMD register is written. To avoid this, these two registers need
> to be written together in a single write operation.
>
> This is implemented as an NVQUIRK as it applies to T114, T124 and
> T132.
>
> Signed-off-by: Pavan Kunapuli <pkunapuli@nvidia.com>
> Signed-off-by: Rhyland Klein <rklein@nvidia.com>
Thanks! Applied for next.
Kind regards
Uffe
> ---
> v2:
> - Fixed quirk flag check s/*/&
> - Removed line clearing xfer_mode_shadow
> - Added explicit mention of which platforms this applies to in
> description
>
> drivers/mmc/host/sdhci-tegra.c | 30 +++++++++++++++++++++++++++++-
> 1 file changed, 29 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/host/sdhci-tegra.c b/drivers/mmc/host/sdhci-tegra.c
> index 59797106af93..f3778d58d1cd 100644
> --- a/drivers/mmc/host/sdhci-tegra.c
> +++ b/drivers/mmc/host/sdhci-tegra.c
> @@ -41,6 +41,7 @@
> #define NVQUIRK_DISABLE_SDR50 BIT(3)
> #define NVQUIRK_DISABLE_SDR104 BIT(4)
> #define NVQUIRK_DISABLE_DDR50 BIT(5)
> +#define NVQUIRK_SHADOW_XFER_MODE_REG BIT(6)
>
> struct sdhci_tegra_soc_data {
> const struct sdhci_pltfm_data *pdata;
> @@ -67,6 +68,31 @@ static u16 tegra_sdhci_readw(struct sdhci_host *host, int reg)
> return readw(host->ioaddr + reg);
> }
>
> +static void tegra_sdhci_writew(struct sdhci_host *host, u16 val, int reg)
> +{
> + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> + struct sdhci_tegra *tegra_host = pltfm_host->priv;
> + const struct sdhci_tegra_soc_data *soc_data = tegra_host->soc_data;
> +
> + if (soc_data->nvquirks & NVQUIRK_SHADOW_XFER_MODE_REG) {
> + switch (reg) {
> + case SDHCI_TRANSFER_MODE:
> + /*
> + * Postpone this write, we must do it together with a
> + * command write that is down below.
> + */
> + pltfm_host->xfer_mode_shadow = val;
> + return;
> + case SDHCI_COMMAND:
> + writel((val << 16) | pltfm_host->xfer_mode_shadow,
> + host->ioaddr + SDHCI_TRANSFER_MODE);
> + return;
> + }
> + }
> +
> + writew(val, host->ioaddr + reg);
> +}
> +
> static void tegra_sdhci_writel(struct sdhci_host *host, u32 val, int reg)
> {
> struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> @@ -147,6 +173,7 @@ static void tegra_sdhci_set_bus_width(struct sdhci_host *host, int bus_width)
> static const struct sdhci_ops tegra_sdhci_ops = {
> .get_ro = tegra_sdhci_get_ro,
> .read_w = tegra_sdhci_readw,
> + .write_w = tegra_sdhci_writew,
> .write_l = tegra_sdhci_writel,
> .set_clock = sdhci_set_clock,
> .set_bus_width = tegra_sdhci_set_bus_width,
> @@ -201,7 +228,8 @@ static struct sdhci_tegra_soc_data soc_data_tegra114 = {
> .pdata = &sdhci_tegra114_pdata,
> .nvquirks = NVQUIRK_DISABLE_SDR50 |
> NVQUIRK_DISABLE_DDR50 |
> - NVQUIRK_DISABLE_SDR104,
> + NVQUIRK_DISABLE_SDR104 |
> + NVQUIRK_SHADOW_XFER_MODE_REG,
> };
>
> static const struct of_device_id sdhci_tegra_dt_match[] = {
> --
> 1.7.9.5
>
^ permalink raw reply [flat|nested] 2+ messages in thread
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