[PATCH v5 4/6] bus: ti-sysc: Add support for software reset
From: tony@atomide.com (Tony Lindgren)
Date: 2018-07-10 11:42:58
Also in:
linux-clk, linux-devicetree, linux-omap, lkml
Subsystem:
omap2+ support, the rest · Maintainers:
Aaro Koskinen, Andreas Kemnade, Kevin Hilman, Roger Quadros, Tony Lindgren, Linus Torvalds
Hi, * Faiz Abbas [off-list ref] [180709 16:50]:
Add support for the software reset of a target interconnect module using its sysconfig and sysstatus registers.
...
quoted hunk ↗ jump to hunk
--- 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 <redacted> 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 <redacted> [tony at atomide.com: updated to check if sysconfig exists] Signed-off-by: Tony Lindgren <tony@atomide.com> --- 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