pinctrl: sh-pfc: r8a7794: Initialize TDSEL register for ES1.0

Documentation for ES1.0 says that some bits in TDSEL must be set (ch
5.3.35 in R-Car E2 v0.5). However, the reset value of the register is 0,
so software has to do it. Add this to the kernel driver to ensure this
is really done independent of firmware versions and use whitelisting for
ES versions known to need this.

This is needed for some SD cards supporting SDR104 transfer mode.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>

diff --git a/drivers/pinctrl/sh-pfc/pfc-r8a7794.c b/drivers/pinctrl/sh-pfc/pfc-r8a7794.c
index fcf1339..958a5f7 100644 (file)
--- a/drivers/pinctrl/sh-pfc/pfc-r8a7794.c
+++ b/drivers/pinctrl/sh-pfc/pfc-r8a7794.c
@@ -8,6 +8,7 @@
  */
 
 #include <linux/kernel.h>
+#include <linux/sys_soc.h>
 
 #include "core.h"
 #include "sh_pfc.h"
@@ -5560,7 +5561,22 @@ static int r8a7794_pin_to_pocctrl(struct sh_pfc *pfc, unsigned int pin, u32 *poc
        return -EINVAL;
 }
 
+static const struct soc_device_attribute r8a7794_tdsel[] = {
+       { .soc_id = "r8a7794", .revision = "ES1.0" },
+       { /* sentinel */ }
+};
+
+static int r8a7794_pinmux_soc_init(struct sh_pfc *pfc)
+{
+       /* Initialize TDSEL on old revisions */
+       if (soc_device_match(r8a7794_tdsel))
+               sh_pfc_write(pfc, 0xe6060068, 0x55555500);
+
+       return 0;
+}
+
 static const struct sh_pfc_soc_operations r8a7794_pinmux_ops = {
+       .init = r8a7794_pinmux_soc_init,
        .pin_to_pocctrl = r8a7794_pin_to_pocctrl,
 };