On Wednesday, April 16, 2014 11:33 PM, Ajay Kumar wrote:
>
> From: Andrew Bresticker <abrestic@xxxxxxxxxxxx>
>
> Certain bridge chips use a GPIO to indicate the cable status instead
> of the I_DP_HPD pin. This adds an optional device-tree property,
> "samsung,hpd-gpio", to the exynos-dp controller which indicates that
> the specified GPIO should be used for hotplug detection.
> The GPIO is then set up as an edge-triggered interrupt where the
> rising edge indicates hotplug-in and the falling edge indicates hotplug-out.
>
> Signed-off-by: Andrew Bresticker <abrestic@xxxxxxxxxxxx>
> Signed-off-by: Rahul Sharma <rahul.sharma@xxxxxxxxxxx>
> Signed-off-by: Ajay Kumar <ajaykumar.rs@xxxxxxxxxxx>
> ---
> .../devicetree/bindings/video/exynos_dp.txt | 4 +++
> drivers/gpu/drm/exynos/exynos_dp_core.c | 32 ++++++++++++++++++++--
> drivers/gpu/drm/exynos/exynos_dp_core.h | 1 +
> drivers/gpu/drm/exynos/exynos_dp_reg.c | 26 ++++++++++++++++--
> 4 files changed, 57 insertions(+), 6 deletions(-)
>
[.....]
> --- a/drivers/gpu/drm/exynos/exynos_dp_reg.c
> +++ b/drivers/gpu/drm/exynos/exynos_dp_reg.c
> @@ -13,6 +13,7 @@
> #include <linux/device.h>
> #include <linux/io.h>
> #include <linux/delay.h>
> +#include <linux/gpio.h>
>
> #include "exynos_dp_core.h"
> #include "exynos_dp_reg.h"
> @@ -326,6 +327,9 @@ void exynos_dp_clear_hotplug_interrupts(struct exynos_dp_device *dp)
> {
> u32 reg;
>
> + if (gpio_is_valid(dp->hpd_gpio))
> + return;
> +
> reg = HOTPLUG_CHG | HPD_LOST | PLUG;
> writel(reg, dp->reg_base + EXYNOS_DP_COMMON_INT_STA_4);
>
> @@ -337,6 +341,9 @@ void exynos_dp_init_hpd(struct exynos_dp_device *dp)
> {
> u32 reg;
>
> + if (gpio_is_valid(dp->hpd_gpio))
> + return;
> +
> exynos_dp_clear_hotplug_interrupts(dp);
>
> reg = readl(dp->reg_base + EXYNOS_DP_SYS_CTL_3);
> @@ -348,6 +355,14 @@ enum dp_irq_type exynos_dp_get_irq_type(struct exynos_dp_device *dp)
> {
> u32 reg;
>
> + if (gpio_is_valid(dp->hpd_gpio)) {
> + reg = gpio_get_value(dp->hpd_gpio);
> + if (reg)
> + return DP_IRQ_TYPE_HP_CABLE_IN;
> + else
> + return DP_IRQ_TYPE_HP_CABLE_OUT;
> + }
> +
Please keep the style. It enhances the readability.
if (gpio_is_valid(dp->hpd_gpio)) {
...
} else {
...
}
Then, it can be as bellows.
+ if (gpio_is_valid(dp->hpd_gpio)) {
+ reg = gpio_get_value(dp->hpd_gpio);
+ if (reg)
+ return DP_IRQ_TYPE_HP_CABLE_IN;
+ else
+ return DP_IRQ_TYPE_HP_CABLE_OUT;
+ } else {
+ /* Parse hotplug interrupt status register */
+ reg = readl(dp->reg_base + EXYNOS_DP_COMMON_INT_STA_4);
+
+ if (reg & PLUG)
+ return DP_IRQ_TYPE_HP_CABLE_IN;
+
+ if (reg & HPD_LOST)
+ return DP_IRQ_TYPE_HP_CABLE_OUT;
+
+ if (reg & HOTPLUG_CHG)
+ return DP_IRQ_TYPE_HP_CHANGE;
+ }
return DP_IRQ_TYPE_UNKNOWN;
}
Best regards,
Jingoo Han
> /* Parse hotplug interrupt status register */
> reg = readl(dp->reg_base + EXYNOS_DP_COMMON_INT_STA_4);
>
> @@ -402,9 +417,14 @@ int exynos_dp_get_plug_in_status(struct exynos_dp_device *dp)
> {
> u32 reg;
>
> - reg = readl(dp->reg_base + EXYNOS_DP_SYS_CTL_3);
> - if (reg & HPD_STATUS)
> - return 0;
> + if (gpio_is_valid(dp->hpd_gpio)) {
> + if (gpio_get_value(dp->hpd_gpio))
> + return 0;
> + } else {
> + reg = readl(dp->reg_base + EXYNOS_DP_SYS_CTL_3);
> + if (reg & HPD_STATUS)
> + return 0;
> + }
>
> return -EINVAL;
> }
> --
> 1.8.1.2
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