From: Alison Chaiken <alison_chaiken@xxxxxxxxxx>
PAD_EIM_D18 must be pulled low at boot in order for the parallel NOR
connected to the EIM switch to probe properly. Otherwise
cfi_qry_present() may return "U-V-]" rather than "Q-R-Y" if the
PAD_EIM_D18 is high. Add a nor-gpios property to the nor node in the
SabreAuto device-tree and add a function to the imx-weim probe to set
GPIO5 to drive the pad.
Signed-off-by: Alison Chaiken <alison_chaiken@xxxxxxxxxx>
---
arch/arm/boot/dts/imx6qdl-sabreauto.dtsi | 1 +
drivers/bus/imx-weim.c | 45 ++++++++++++++++++++++++++++++++
2 files changed, 46 insertions(+)
diff --git a/arch/arm/boot/dts/imx6qdl-sabreauto.dtsi b/arch/arm/boot/dts/imx6qdl-sabreauto.dtsi
index 8263fc1..530b4d6 100644
--- a/arch/arm/boot/dts/imx6qdl-sabreauto.dtsi
+++ b/arch/arm/boot/dts/imx6qdl-sabreauto.dtsi
@@ -625,5 +625,6 @@
bank-width = <2>;
fsl,weim-cs-timing = <0x00620081 0x00000001 0x1c022000
0x0000c000 0x1404a38e 0x00000000>;
+ nor-gpios = <&gpio5 4 GPIO_ACTIVE_LOW>;
};
};
diff --git a/drivers/bus/imx-weim.c b/drivers/bus/imx-weim.c
index e98d15e..7b841d4 100644
--- a/drivers/bus/imx-weim.c
+++ b/drivers/bus/imx-weim.c
@@ -14,6 +14,8 @@
#include <linux/mfd/syscon.h>
#include <linux/mfd/syscon/imx6q-iomuxc-gpr.h>
#include <linux/regmap.h>
+#include <linux/of_gpio.h>
+#include <linux/gpio.h>
struct imx_weim_devtype {
unsigned int cs_count;
@@ -108,6 +110,40 @@ err:
return -EINVAL;
}
+/* set the GPIO to control PAD_EIM_D18 so cfi_qry_present() works properly */
+static int __init nor_gpio_setup(struct device_node *np, struct device *parent)
+{
+ unsigned nor_gpio, level;
+ enum of_gpio_flags of_flags;
+ int ret;
+
+ nor_gpio = of_get_named_gpio_flags(np, "nor-gpios", 0, &of_flags);
+
+ /* this child is not a NOR chip */
+ if (!nor_gpio)
+ return 0;
+
+ if (gpio_is_valid(nor_gpio)) {
+ ret = devm_gpio_request_one(parent, nor_gpio,
+ GPIOF_DIR_OUT, "nor-gpio");
+ } else {
+ ret = -ENODEV;
+ goto out;
+ }
+
+ if (ret < 0)
+ goto out;
+
+ level = ((of_flags == OF_GPIO_ACTIVE_LOW) ? 0 : 1);
+
+ gpio_set_value(nor_gpio, level);
+
+ return 0;
+out:
+ dev_err(parent, "Unable to request EIM_D18 GPIO for NOR.\n");
+ return ret;
+}
+
/* Parse and set the timing for this device. */
static int __init weim_timing_setup(struct device_node *np, void __iomem *base,
const struct imx_weim_devtype *devtype)
@@ -154,6 +190,15 @@ static int __init weim_parse_dt(struct platform_device *pdev,
if (!child->name)
continue;
+ if (of_device_is_compatible(child, "cfi-flash")) {
+ ret = nor_gpio_setup(child, &pdev->dev);
+ if (ret) {
+ dev_err(&pdev->dev, "%s gpios setup failed.\n",
+ child->full_name);
+ return ret;
+ }
+ }
+
ret = weim_timing_setup(child, base, devtype);
if (ret)
dev_warn(&pdev->dev, "%s set timing failed.\n",
--
2.6.2
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