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authorLad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>2021-11-18 06:10:40 +0300
committerMark Brown <broonie@kernel.org>2021-11-18 16:57:54 +0300
commitaadbff4af5c90919cbe67e2c4d77c68cdefa454e (patch)
tree13c68fa93c5372b459e8ed68070af46d2aaaff33 /drivers/spi
parent5a8f8542e34b6469cd5c5a3d075fa5977d90775e (diff)
downloadlinux-aadbff4af5c90919cbe67e2c4d77c68cdefa454e.tar.xz
spi: spi-rspi: Add support to deassert/assert reset line
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> Link: https://lore.kernel.org/r/20211118031041.2312-3-prabhakar.mahadev-lad.rj@bp.renesas.com Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/spi')
-rw-r--r--drivers/spi/spi-rspi.c25
1 files changed, 25 insertions, 0 deletions
diff --git a/drivers/spi/spi-rspi.c b/drivers/spi/spi-rspi.c
index 41761f0d892a..b7df49a57e5f 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