The TiWi 5 WiFi module needs special setup of the sdio
interface before it can be probed.
So far, this is done in omap_hsmmc_init_card() in omap_hsmmc.c
which makes it useable only if connected to omap devices
which use the omap_hsmmc. The OpenPandora is the most promient
example.
There are plans to switch to a newer sdhci-omap driver and
retire omap_hsmmc. Hence this quirk must be reworked or moved
somewhere else. Ideally to some location that is not dependent
on the specific SoC mmc host driver.
Analysis has shown that omap_hsmmc_init_card() is called
through the host->ops->init_card hook which itself
is called in three generic locations:
mmc_init_card()
mmc_sd_init_card()
mmc_sdio_init_card()
All these functions share a call to mmc_select_card() shortly
after running the init hook and therefore I assume that
a good place transplanting the special wl1251 handling is
mmc_select_card() - unless we want to copy and maintain the
code to three different places.
After this quirk has been moved there, we can remove
omap_hsmmc_init_card() in omap_hsmmc.c in a separate patch.
Indeed the plan is to remove omap_hsmmc.c completely.
A future development path to generalize could be to make
the code not depend on compatible = "ti,wl1251" but check
for optional device tree properties (non-std-sdio, bus width,
vendor, device, blksize, max_dtr, ocr) which can be defined
for any child device of the mmd/sd port needing such special
setup.
Related-to: commit f6498b922e57 ("mmc: host: omap_hsmmc: add code for special init of wl1251 to get rid of pandora_wl1251_init_card")
Related-to: commit 2398c41d6432 ("omap: pdata-quirks: remove openpandora quirks for mmc3 and wl1251")
Related-to: commit f9d50fef4b64 ("ARM: OMAP2+: omap3-pandora: add wifi support")
Tested-by: H. Nikolaus Schaller <hns@xxxxxxxxxxxxx> # on OpenPandora
Signed-off-by: H. Nikolaus Schaller <hns@xxxxxxxxxxxxx>
---
drivers/mmc/core/mmc_ops.c | 30 ++++++++++++++++++++++++++++++
1 file changed, 30 insertions(+)
diff --git a/drivers/mmc/core/mmc_ops.c b/drivers/mmc/core/mmc_ops.c
index 0c54858e89c0..6f9b96be9fe6 100644
--- a/drivers/mmc/core/mmc_ops.c
+++ b/drivers/mmc/core/mmc_ops.c
@@ -7,6 +7,7 @@
#include <linux/slab.h>
#include <linux/export.h>
+#include <linux/of.h>
#include <linux/types.h>
#include <linux/scatterlist.h>
@@ -107,6 +108,35 @@ static int _mmc_select_card(struct mmc_host *host, struct mmc_card *card)
int mmc_select_card(struct mmc_card *card)
{
+ if (card->type == MMC_TYPE_SDIO || card->type == MMC_TYPE_SD_COMBO) {
+ struct device_node *np = card->host->parent->of_node;
+
+ /*
+ * REVISIT: should be made more general
+ * e.g. by expanding the DT bindings of child nodes to
+ * optionally provide this information:
+ * Documentation/devicetree/bindings/mmc/mmc-card.txt
+ */
+
+ np = of_get_compatible_child(np, "ti,wl1251");
+ if (np) {
+ /*
+ * We have TI wl1251 attached to this mmc. Pass this
+ * information to the SDIO core because it can't be
+ * probed by normal methods.
+ */
+
+ dev_info(card->host->parent, "found wl1251\n");
+ card->quirks |= MMC_QUIRK_NONSTD_SDIO;
+ card->cccr.wide_bus = 1;
+ card->cis.vendor = 0x104c;
+ card->cis.device = 0x9066;
+ card->cis.blksize = 512;
+ card->cis.max_dtr = 24000000;
+ card->ocr = 0x80;
+ of_node_put(np);
+ }
+ }
return _mmc_select_card(card->host, card);
}
--
2.33.0
