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authorPeter Chen <peter.chen@freescale.com>2014-01-10 13:51:27 +0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-01-13 15:55:19 -0800
commited8f8318d2ef3e5f9e4ddf79349508c116b68d7f (patch)
treefc8309d0c9eb301472c321c3eb339e49ccc72f65 /drivers/usb
parentfeffe09f510c475df082546815f9e4a573f6a233 (diff)
usb: chipidea: add freescale imx28 special write register method
According to Freescale imx28 Errata, "ENGR119653 USB: ARM to USB register error issue", All USB register write operations must use the ARM SWP instruction. So, we implement special hw_write and hw_test_and_clear for imx28. Discussion for it at below: http://marc.info/?l=linux-usb&m=137996395529294&w=2 This patch is needed for stable tree 3.11+. Cc: stable@vger.kernel.org Cc: robert.hodaszi@digi.com Signed-off-by: Peter Chen <peter.chen@freescale.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> Tested-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb')
-rw-r--r--drivers/usb/chipidea/ci.h26
-rw-r--r--drivers/usb/chipidea/core.c2
-rw-r--r--drivers/usb/chipidea/host.c1
3 files changed, 27 insertions, 2 deletions
diff --git a/drivers/usb/chipidea/ci.h b/drivers/usb/chipidea/ci.h
index a71dc1c89aa2..88b80f7728e4 100644
--- a/drivers/usb/chipidea/ci.h
+++ b/drivers/usb/chipidea/ci.h
@@ -164,6 +164,7 @@ struct hw_bank {
* @id_event: indicates there is an id event, and handled at ci_otg_work
* @b_sess_valid_event: indicates there is a vbus event, and handled
* at ci_otg_work
+ * @imx28_write_fix: Freescale imx28 needs swp instruction for writing
*/
struct ci_hdrc {
struct device *dev;
@@ -202,6 +203,7 @@ struct ci_hdrc {
struct dentry *debugfs;
bool id_event;
bool b_sess_valid_event;
+ bool imx28_write_fix;
};
static inline struct ci_role_driver *ci_role(struct ci_hdrc *ci)
@@ -250,6 +252,26 @@ static inline u32 hw_read(struct ci_hdrc *ci, enum ci_hw_regs reg, u32 mask)
return ioread32(ci->hw_bank.regmap[reg]) & mask;
}
+#ifdef CONFIG_SOC_IMX28
+static inline void imx28_ci_writel(u32 val, volatile void __iomem *addr)
+{
+ __asm__ ("swp %0, %0, [%1]" : : "r"(val), "r"(addr));
+}
+#else
+static inline void imx28_ci_writel(u32 val, volatile void __iomem *addr)
+{
+}
+#endif
+
+static inline void __hw_write(struct ci_hdrc *ci, u32 val,
+ void __iomem *addr)
+{
+ if (ci->imx28_write_fix)
+ imx28_ci_writel(val, addr);
+ else
+ iowrite32(val, addr);
+}
+
/**
* hw_write: writes to a hw register
* @reg: register index
@@ -263,7 +285,7 @@ static inline void hw_write(struct ci_hdrc *ci, enum ci_hw_regs reg,
data = (ioread32(ci->hw_bank.regmap[reg]) & ~mask)
| (data & mask);
- iowrite32(data, ci->hw_bank.regmap[reg]);
+ __hw_write(ci, data, ci->hw_bank.regmap[reg]);
}
/**
@@ -278,7 +300,7 @@ static inline u32 hw_test_and_clear(struct ci_hdrc *ci, enum ci_hw_regs reg,
{
u32 val = ioread32(ci->hw_bank.regmap[reg]) & mask;
- iowrite32(val, ci->hw_bank.regmap[reg]);
+ __hw_write(ci, val, ci->hw_bank.regmap[reg]);
return val;
}
diff --git a/drivers/usb/chipidea/core.c b/drivers/usb/chipidea/core.c
index 458d8e412505..0ead0b4a11e1 100644
--- a/drivers/usb/chipidea/core.c
+++ b/drivers/usb/chipidea/core.c
@@ -548,6 +548,8 @@ static int ci_hdrc_probe(struct platform_device *pdev)
ci->dev = dev;
ci->platdata = dev->platform_data;
+ ci->imx28_write_fix = !!(ci->platdata->flags &
+ CI_HDRC_IMX28_WRITE_FIX);
ret = hw_device_init(ci, base);
if (ret < 0) {
diff --git a/drivers/usb/chipidea/host.c b/drivers/usb/chipidea/host.c
index 526cd77563d8..a8ac6c16dac9 100644
--- a/drivers/usb/chipidea/host.c
+++ b/drivers/usb/chipidea/host.c
@@ -65,6 +65,7 @@ static int host_start(struct ci_hdrc *ci)
ehci->caps = ci->hw_bank.cap;
ehci->has_hostpc = ci->hw_bank.lpm;
ehci->has_tdi_phy_lpm = ci->hw_bank.lpm;
+ ehci->imx28_write_fix = ci->imx28_write_fix;
if (ci->platdata->reg_vbus) {
ret = regulator_enable(ci->platdata->reg_vbus);