Hi,
* Faiz Abbas <faiz_abbas@xxxxxx> [180709 16:50]:
> Add support for the software reset of a target interconnect
> module using its sysconfig and sysstatus registers.
...
> --- a/drivers/bus/ti-sysc.c
> +++ b/drivers/bus/ti-sysc.c
...
> +static int sysc_reset(struct sysc *ddata)
> +{
> + int offset = ddata->offsets[SYSC_SYSCONFIG];
> + int val = sysc_read(ddata, offset);
Testing with omap4 sysc dts data I noticed we already
have modules where there is only rev register and no
SYSC_SYSCONFIG. So not using legacy mode. The
above offset with -ENODEV value will not work :)
I added some more checks and moved them to the reset
function.
Updated patch below for reference, I've pushed out
new branches omap-for-v4.19/ti-sysc-v2 and
omap-for-v4.19/dt-mcan-v2. I've also updated my
for-next branch.
Regards,
Tony
8< -----------
>From tony Mon Sep 17 00:00:00 2001
From: Faiz Abbas <faiz_abbas@xxxxxx>
Date: Mon, 9 Jul 2018 22:18:39 +0530
Subject: [PATCH] bus: ti-sysc: Add support for software reset
Add support for the software reset of a target interconnect
module using its sysconfig and sysstatus registers.
Signed-off-by: Faiz Abbas <faiz_abbas@xxxxxx>
[tony@xxxxxxxxxxx: updated to check if sysconfig exists]
Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx>
---
drivers/bus/ti-sysc.c | 46 +++++++++++++++++++++++++++++++++++++++++++
1 file changed, 46 insertions(+)
diff --git a/drivers/bus/ti-sysc.c b/drivers/bus/ti-sysc.c
--- a/drivers/bus/ti-sysc.c
+++ b/drivers/bus/ti-sysc.c
@@ -23,11 +23,14 @@
#include <linux/of_address.h>
#include <linux/of_platform.h>
#include <linux/slab.h>
+#include <linux/iopoll.h>
#include <linux/platform_data/ti-sysc.h>
#include <dt-bindings/bus/ti-sysc.h>
+#define MAX_MODULE_SOFTRESET_WAIT 10000
+
static const char * const reg_names[] = { "rev", "sysc", "syss", };
enum sysc_clocks {
@@ -88,6 +91,11 @@ struct sysc {
struct delayed_work idle_work;
};
+void sysc_write(struct sysc *ddata, int offset, u32 value)
+{
+ writel_relaxed(value, ddata->module_va + offset);
+}
+
static u32 sysc_read(struct sysc *ddata, int offset)
{
if (ddata->cfg.quirks & SYSC_QUIRK_16BIT) {
@@ -943,6 +951,36 @@ static void sysc_init_revision_quirks(struct sysc *ddata)
}
}
+static int sysc_reset(struct sysc *ddata)
+{
+ int offset = ddata->offsets[SYSC_SYSCONFIG];
+ int val;
+
+ if (ddata->legacy_mode || offset < 0 ||
+ ddata->cfg.quirks & SYSC_QUIRK_NO_RESET_ON_INIT)
+ return 0;
+
+ /*
+ * Currently only support reset status in sysstatus.
+ * Warn and return error in all other cases
+ */
+ if (!ddata->cfg.syss_mask) {
+ dev_err(ddata->dev, "No ti,syss-mask. Reset failed\n");
+ return -EINVAL;
+ }
+
+ val = sysc_read(ddata, offset);
+ val |= (0x1 << ddata->cap->regbits->srst_shift);
+ sysc_write(ddata, offset, val);
+
+ /* Poll on reset status */
+ offset = ddata->offsets[SYSC_SYSSTATUS];
+
+ return readl_poll_timeout(ddata->module_va + offset, val,
+ (val & ddata->cfg.syss_mask) == 0x0,
+ 100, MAX_MODULE_SOFTRESET_WAIT);
+}
+
/* At this point the module is configured enough to read the revision */
static int sysc_init_module(struct sysc *ddata)
{
@@ -960,6 +998,14 @@ static int sysc_init_module(struct sysc *ddata)
return 0;
}
+ error = sysc_reset(ddata);
+ if (error) {
+ dev_err(ddata->dev, "Reset failed with %d\n", error);
+ pm_runtime_put_sync(ddata->dev);
+
+ return error;
+ }
+
ddata->revision = sysc_read_revision(ddata);
pm_runtime_put_sync(ddata->dev);
--
2.17.1
--
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