diff mbox series

[2/3] spi: spi-rspi: Add support to deassert/assert reset line

Message ID 20211117010527.27365-3-prabhakar.mahadev-lad.rj@bp.renesas.com (mailing list archive)
State Superseded
Delegated to: Geert Uytterhoeven
Headers show
Series SPI driver support for RZ/G2L | expand

Commit Message

Prabhakar Nov. 17, 2021, 1:05 a.m. UTC 
On RZ/G2L SoC we need to explicitly deassert the reset line
for the device to work, use this opportunity to deassert/assert
reset line in spi-rspi driver.

This patch adds support to read the "resets" property (if available)
from DT and perform deassert/assert when required.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Biju Das <biju.das.jz@bp.renesas.com>
---
 drivers/spi/spi-rspi.c | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

Comments

Geert Uytterhoeven Nov. 17, 2021, 8:55 a.m. UTC | #1 
On Wed, Nov 17, 2021 at 2:05 AM Lad Prabhakar
<prabhakar.mahadev-lad.rj@bp.renesas.com> wrote:
> On RZ/G2L SoC we need to explicitly deassert the reset line
> for the device to work, use this opportunity to deassert/assert
> reset line in spi-rspi driver.
>
> This patch adds support to read the "resets" property (if available)
> from DT and perform deassert/assert when required.
>
> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> Reviewed-by: Biju Das <biju.das.jz@bp.renesas.com>

Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>

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
diff mbox series

Patch

diff --git a/drivers/spi/spi-rspi.c b/drivers/spi/spi-rspi.c
index d16ed88802d3..592682d96562 100644
--- a/drivers/spi/spi-rspi.c
+++ b/drivers/spi/spi-rspi.c
@@ -21,6 +21,7 @@ 
 #include <linux/dma-mapping.h>
 #include <linux/of_device.h>
 #include <linux/pm_runtime.h>
+#include <linux/reset.h>
 #include <linux/sh_dma.h>
 #include <linux/spi/spi.h>
 #include <linux/spi/rspi.h>
@@ -1225,8 +1226,14 @@  static const struct of_device_id rspi_of_match[] = {
 
 MODULE_DEVICE_TABLE(of, rspi_of_match);
 
+static void rspi_reset_control_assert(void *data)
+{
+	reset_control_assert(data);
+}
+
 static int rspi_parse_dt(struct device *dev, struct spi_controller *ctlr)
 {
+	struct reset_control *rstc;
 	u32 num_cs;
 	int error;
 
@@ -1238,6 +1245,24 @@  static int rspi_parse_dt(struct device *dev, struct spi_controller *ctlr)
 	}
 
 	ctlr->num_chipselect = num_cs;
+
+	rstc = devm_reset_control_get_optional_exclusive(dev, NULL);
+	if (IS_ERR(rstc))
+		return dev_err_probe(dev, PTR_ERR(rstc),
+					     "failed to get reset ctrl\n");
+
+	error = reset_control_deassert(rstc);
+	if (error) {
+		dev_err(dev, "failed to deassert reset %d\n", error);
+		return error;
+	}
+
+	error = devm_add_action_or_reset(dev, rspi_reset_control_assert, rstc);
+	if (error) {
+		dev_err(dev, "failed to register assert devm action, %d\n", error);
+		return error;
+	}
+
 	return 0;
 }
 #else