[v2,2/2] pinctrl: sh-pfc: r8a7794: initialize TDSEL register for ES1.0

Message ID 20190107221320.14930-3-wsa+renesas@sang-engineering.com
State New
Headers show
Series
  • pinctrl: sh-pfc: gen2: initialize TDSEL register for ES1.0
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Commit Message

Wolfram Sang Jan. 7, 2019, 10:13 p.m.
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>
---
 drivers/pinctrl/sh-pfc/pfc-r8a7794.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

Comments

Simon Horman Jan. 8, 2019, 3:07 p.m. | #1
On Mon, Jan 07, 2019 at 11:13:20PM +0100, Wolfram Sang wrote:
> 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.

Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Geert Uytterhoeven Jan. 9, 2019, 8:35 a.m. | #2
On Mon, Jan 7, 2019 at 11:13 PM Wolfram Sang
<wsa+renesas@sang-engineering.com> wrote:
> 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,

Hardware User Manual Rev.1.10 says the values must be 00, so I assume
that manual applies to later ES versions.

> 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: Geert Uytterhoeven <geert+renesas@glider.be>
i.e. will queue in sh-pfc-for-v5.1.

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Patch

diff --git a/drivers/pinctrl/sh-pfc/pfc-r8a7794.c b/drivers/pinctrl/sh-pfc/pfc-r8a7794.c
index fcf1339c4058..958a5f714c93 100644
--- 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,
 };