We can easily detect i2c based on it's non-standard module registers that
consist of two 32-bit registers accessed in 16-bit mode.
So far we don't have other 16-bit modules, so there's currently no need
to add a custom property for 16-bit register access.
Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx>
---
drivers/bus/ti-sysc.c | 17 +++++++++++++++++
include/linux/platform_data/ti-sysc.h | 1 +
2 files changed, 18 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
@@ -213,6 +213,21 @@ static int sysc_check_children(struct sysc *ddata)
return 0;
}
+/*
+ * So far only I2C uses 16-bit read access with clockactivity with revision
+ * in two registers with stride of 4. We can detect this based on the rev
+ * register size to configure things far enough to be able to properly read
+ * the revision register.
+ */
+static void sysc_check_quirk_16bit(struct sysc *ddata, struct resource *res)
+{
+ if (resource_size(res) == 8) {
+ dev_dbg(ddata->dev,
+ "enabling 16-bit and clockactivity quirks\n");
+ ddata->cfg.quirks |= SYSC_QUIRK_16BIT | SYSC_QUIRK_USE_CLOCKACT;
+ }
+}
+
/**
* sysc_parse_one - parses the interconnect target module registers
* @ddata: device driver data
@@ -243,6 +258,8 @@ static int sysc_parse_one(struct sysc *ddata, enum sysc_registers reg)
}
ddata->offsets[reg] = res->start - ddata->module_pa;
+ if (reg == SYSC_REVISION)
+ sysc_check_quirk_16bit(ddata, res);
return 0;
}
diff --git a/include/linux/platform_data/ti-sysc.h b/include/linux/platform_data/ti-sysc.h
--- a/include/linux/platform_data/ti-sysc.h
+++ b/include/linux/platform_data/ti-sysc.h
@@ -41,6 +41,7 @@ struct sysc_regbits {
s8 emufree_shift;
};
+#define SYSC_QUIRK_16BIT BIT(2)
#define SYSC_QUIRK_UNCACHED BIT(1)
#define SYSC_QUIRK_USE_CLOCKACT BIT(0)
--
2.15.0
--
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