[PATCH V2 1/2] mmc: omap_hsmmc: Add support for quirky omap3 hsmmc controller

From: Nishanth Menon
Date: Fri Feb 14 2014 - 00:46:40 EST


When device is booted using devicetree, platforms impacted by Erratum
2.1.1.128 is not detected easily in the mmc driver. This erratum
indicates that the module cannot do multi-block transfers. Platforms
such as LDP which use OMAP3 ES revision prior to ES3.0 are impacted by
this.

Provide a new compatible property "ti,omap3-pre-es3-hsmmc" to allow
driver to determine if driver needs to implement quirks associated
with the specific module version (primarily because the IP revision
information is not sufficient for the same).

Signed-off-by: Nishanth Menon <nm@xxxxxx>
---
Changes since v1:
- new compatible flag as suggested by Tony which contains
the relevant controller flag to work around the erratum

V1: https://patchwork.kernel.org/patch/3514851/

.../devicetree/bindings/mmc/ti-omap-hsmmc.txt | 1 +
drivers/mmc/host/omap_hsmmc.c | 26 +++++++++++++++++---
2 files changed, 23 insertions(+), 4 deletions(-)

diff --git a/Documentation/devicetree/bindings/mmc/ti-omap-hsmmc.txt b/Documentation/devicetree/bindings/mmc/ti-omap-hsmmc.txt
index 8c8908a..ce80561 100644
--- a/Documentation/devicetree/bindings/mmc/ti-omap-hsmmc.txt
+++ b/Documentation/devicetree/bindings/mmc/ti-omap-hsmmc.txt
@@ -10,6 +10,7 @@ Required properties:
- compatible:
Should be "ti,omap2-hsmmc", for OMAP2 controllers
Should be "ti,omap3-hsmmc", for OMAP3 controllers
+ Should be "ti,omap3-pre-es3-hsmmc" for OMAP3 controllers pre ES3.0
Should be "ti,omap4-hsmmc", for OMAP4 controllers
- ti,hwmods: Must be "mmc<n>", n is controller instance starting 1

diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c
index 575f9cc..390f421 100644
--- a/drivers/mmc/host/omap_hsmmc.c
+++ b/drivers/mmc/host/omap_hsmmc.c
@@ -192,6 +192,11 @@ struct omap_hsmmc_host {
struct omap_mmc_platform_data *pdata;
};

+struct omap_mmc_of_data {
+ u32 reg_offset;
+ u8 controller_flags;
+};
+
static int omap_hsmmc_card_detect(struct device *dev, int slot)
{
struct omap_hsmmc_host *host = dev_get_drvdata(dev);
@@ -1678,18 +1683,29 @@ static void omap_hsmmc_debugfs(struct mmc_host *mmc)
#endif

#ifdef CONFIG_OF
-static u16 omap4_reg_offset = 0x100;
+static const struct omap_mmc_of_data omap3_pre_es3_mmc_of_data = {
+ /* See 35xx errata 2.1.1.128 in SPRZ278F */
+ .controller_flags = OMAP_HSMMC_BROKEN_MULTIBLOCK_READ,
+};
+
+static const struct omap_mmc_of_data omap4_mmc_of_data = {
+ .reg_offset = 0x100,
+};

static const struct of_device_id omap_mmc_of_match[] = {
{
.compatible = "ti,omap2-hsmmc",
},
{
+ .compatible = "ti,omap3-pre-es3-hsmmc",
+ .data = &omap3_pre_es3_mmc_of_data,
+ },
+ {
.compatible = "ti,omap3-hsmmc",
},
{
.compatible = "ti,omap4-hsmmc",
- .data = &omap4_reg_offset,
+ .data = &omap4_mmc_of_data,
},
{},
};
@@ -1759,6 +1775,7 @@ static int omap_hsmmc_probe(struct platform_device *pdev)
dma_cap_mask_t mask;
unsigned tx_req, rx_req;
struct pinctrl *pinctrl;
+ const struct omap_mmc_of_data *data;

match = of_match_device(of_match_ptr(omap_mmc_of_match), &pdev->dev);
if (match) {
@@ -1768,8 +1785,9 @@ static int omap_hsmmc_probe(struct platform_device *pdev)
return PTR_ERR(pdata);

if (match->data) {
- const u16 *offsetp = match->data;
- pdata->reg_offset = *offsetp;
+ data = match->data;
+ pdata->reg_offset = data->reg_offset;
+ pdata->controller_flags |= data->controller_flags;
}
}

--
1.7.9.5

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