| Message ID | 1449372657-18496-2-git-send-email-alison_chaiken@mentor.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Sat, Dec 05, 2015 at 07:30:56PM -0800, alchaiken@gmail.com wrote: > From: Alison Chaiken <alison_chaiken@mentor.com> > > 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@mentor.com> > --- > 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>; > }; > }; Please do not make board specific and driver specific changes in a single patch. Also this would need an update to the binding documentation. How is this pin connected? Is this a problem of this NOR flash, something i.MX6 specific or some problem of this particular board? Depending on the answer we may find a better place to implement the handling of this gpio. If it's a board problem Markus Pargmanns gpio-initval series is better suited, if it's a problem of the NOR flash the parallel NOR flash driver is a better place. Sascha
The parallel NOR that is attached to the i.MX6-SabreAuto WEIM switch
needs a GPIO asserted at boot in order to probe properly. Employ the
GPIO init-val mechanism to set the GPIO. Also, add partitions subnode
to NOR device-tree node to make MTD initialization work.
Alison Chaiken (2):
ARM: dts: imx6qdl-sabreauto: assert GPIO at boot in order to connect
NOR
ARM: dts: imx6qdl-sabreauto: enable partitions for parallel NOR
arch/arm/boot/dts/imx6qdl-sabreauto-eim-nor.dtsi | 43 ++++++++++++++++++++++++
arch/arm/boot/dts/imx6qdl-sabreauto.dtsi | 4 +++
2 files changed, 47 insertions(+)
create mode 100644 arch/arm/boot/dts/imx6qdl-sabreauto-eim-nor.dtsi
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",