[PATCH 10/12] drm/tegra: Add pinctrl support for DPAUX

Jon Hunter
2016-06-23T15:59:03Z

The DPAUX pins are shared with an internal I2C controller. To allow
these pins to be muxed to the I2C controller, register a pinctrl device
for the DPAUX device. Make Tegra DRM support dependent on PINCTRL to
avoid any compilation issues.

This is based upon work by Thierry Reding <treding@nvidia.com>.

Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
---
drivers/gpu/drm/tegra/dpaux.c | 122 ++++++++++++++++++++++++++++++++++++++++--
1 file changed, 119 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/tegra/dpaux.c b/drivers/gpu/drm/tegra/dpaux.c
index 61821f457209..7b2abaf33a7a 100644
--- a/drivers/gpu/drm/tegra/dpaux.c
+++ b/drivers/gpu/drm/tegra/dpaux.c
@@ -12,6 +12,9 @@
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/of_gpio.h>
+#include <linux/pinctrl/pinconf-generic.h>
+#include <linux/pinctrl/pinctrl.h>
+#include <linux/pinctrl/pinmux.h>
#include <linux/platform_device.h>
#include <linux/reset.h>
#include <linux/regulator/consumer.h>
@@ -44,6 +47,11 @@ struct tegra_dpaux {
struct completion complete;
struct work_struct work;
struct list_head list;
+
+#ifdef CONFIG_PINCTRL
+ struct pinctrl_dev *pinctrl;
+ struct pinctrl_desc desc;
+#endif
};

static inline struct tegra_dpaux *to_dpaux(struct drm_dp_aux *aux)
@@ -267,6 +275,12 @@ static irqreturn_t tegra_dpaux_irq(int irq, void *data)
return ret;
}

+enum tegra_dpaux_functions {
+ DPAUX_PADCTL_FUNC_AUX,
+ DPAUX_PADCTL_FUNC_I2C,
+ DPAUX_PADCTL_FUNC_OFF,
+};
+
static void tegra_dpaux_pad_power_down(struct tegra_dpaux *dpaux)
{
u32 value = tegra_dpaux_readl(dpaux, DPAUX_HYBRID_SPARE);
@@ -290,18 +304,21 @@ static int tegra_dpaux_pad_config(struct tegra_dpaux *dpaux, unsigned function)
u32 value;

switch (function) {
- case DPAUX_HYBRID_PADCTL_MODE_AUX:
+ case DPAUX_PADCTL_FUNC_AUX:
value = DPAUX_HYBRID_PADCTL_AUX_CMH(2) |
DPAUX_HYBRID_PADCTL_AUX_DRVZ(4) |
DPAUX_HYBRID_PADCTL_AUX_DRVI(0x18) |
DPAUX_HYBRID_PADCTL_AUX_INPUT_RCV |
DPAUX_HYBRID_PADCTL_MODE_AUX;
break;
- case DPAUX_HYBRID_PADCTL_MODE_I2C:
+ case DPAUX_PADCTL_FUNC_I2C:
value = DPAUX_HYBRID_PADCTL_I2C_SDA_INPUT_RCV |
DPAUX_HYBRID_PADCTL_I2C_SCL_INPUT_RCV |
DPAUX_HYBRID_PADCTL_MODE_I2C;
break;
+ case DPAUX_PADCTL_FUNC_OFF:
+ tegra_dpaux_pad_power_down(dpaux);
+ return 0;
default:
return -ENOTSUPP;
}
@@ -312,6 +329,91 @@ static int tegra_dpaux_pad_config(struct tegra_dpaux *dpaux, unsigned function)
return 0;
}

+#ifdef CONFIG_PINCTRL
+static const struct pinctrl_pin_desc tegra_dpaux_pins[] = {
+ PINCTRL_PIN(0, "DP_AUX_CHx_P"),
+ PINCTRL_PIN(1, "DP_AUX_CHx_N"),
+};
+
+static const unsigned tegra_dpaux_pin_numbers[] = { 0, 1 };
+
+static const char * const tegra_dpaux_groups[] = {
+ "dpaux-io",
+};
+
+static const char * const tegra_dpaux_functions[] = {
+ "aux",
+ "i2c",
+ "off",
+};
+
+static int tegra_dpaux_get_groups_count(struct pinctrl_dev *pinctrl)
+{
+ return ARRAY_SIZE(tegra_dpaux_groups);
+}
+
+static const char *tegra_dpaux_get_group_name(struct pinctrl_dev *pinctrl,
+ unsigned int group)
+{
+ return tegra_dpaux_groups[group];
+}
+
+static int tegra_dpaux_get_group_pins(struct pinctrl_dev *pinctrl,
+ unsigned group, const unsigned **pins,
+ unsigned *num_pins)
+{
+ *pins = tegra_dpaux_pin_numbers;
+ *num_pins = ARRAY_SIZE(tegra_dpaux_pin_numbers);
+
+ return 0;
+}
+
+static const struct pinctrl_ops tegra_dpaux_pinctrl_ops = {
+ .get_groups_count = tegra_dpaux_get_groups_count,
+ .get_group_name = tegra_dpaux_get_group_name,
+ .get_group_pins = tegra_dpaux_get_group_pins,
+ .dt_node_to_map = pinconf_generic_dt_node_to_map_group,
+ .dt_free_map = pinconf_generic_dt_free_map,
+};
+
+static int tegra_dpaux_get_functions_count(struct pinctrl_dev *pinctrl)
+{
+ return ARRAY_SIZE(tegra_dpaux_functions);
+}
+
+static const char *tegra_dpaux_get_function_name(struct pinctrl_dev *pinctrl,
+ unsigned int function)
+{
+ return tegra_dpaux_functions[function];
+}
+
+static int tegra_dpaux_get_function_groups(struct pinctrl_dev *pinctrl,
+ unsigned int function,
+ const char * const **groups,
+ unsigned * const num_groups)
+{
+ *num_groups = ARRAY_SIZE(tegra_dpaux_groups);
+ *groups = tegra_dpaux_groups;
+
+ return 0;
+}
+
+static int tegra_dpaux_set_mux(struct pinctrl_dev *pinctrl,
+ unsigned int function, unsigned int group)
+{
+ struct tegra_dpaux *dpaux = pinctrl_dev_get_drvdata(pinctrl);
+
+ return tegra_dpaux_pad_config(dpaux, function);
+}
+
+static const struct pinmux_ops tegra_dpaux_pinmux_ops = {
+ .get_functions_count = tegra_dpaux_get_functions_count,
+ .get_function_name = tegra_dpaux_get_function_name,
+ .get_function_groups = tegra_dpaux_get_function_groups,
+ .set_mux = tegra_dpaux_set_mux,
+};
+#endif
+
static int tegra_dpaux_probe(struct platform_device *pdev)
{
struct tegra_dpaux *dpaux;
@@ -425,6 +527,20 @@ static int tegra_dpaux_probe(struct platform_device *pdev)
if (err < 0)
return err;

+#ifdef CONFIG_PINCTRL
+ dpaux->desc.name = dev_name(&pdev->dev);
+ dpaux->desc.pins = tegra_dpaux_pins;
+ dpaux->desc.npins = ARRAY_SIZE(tegra_dpaux_pins);
+ dpaux->desc.pctlops = &tegra_dpaux_pinctrl_ops;
+ dpaux->desc.pmxops = &tegra_dpaux_pinmux_ops;
+ dpaux->desc.owner = THIS_MODULE;
+
+ dpaux->pinctrl = devm_pinctrl_register(&pdev->dev, &dpaux->desc, dpaux);
+ if (!dpaux->pinctrl) {
+ dev_err(&pdev->dev, "failed to register pincontrol\n");
+ return -ENODEV;
+ }
+#endif
/* enable and clear all interrupts */
value = DPAUX_INTR_AUX_DONE | DPAUX_INTR_IRQ_EVENT |
DPAUX_INTR_UNPLUG_EVENT | DPAUX_INTR_PLUG_EVENT;
@@ -581,7 +697,7 @@ int drm_dp_aux_enable(struct drm_dp_aux *aux)
{
struct tegra_dpaux *dpaux = to_dpaux(aux);

- return tegra_dpaux_pad_config(dpaux, DPAUX_HYBRID_PADCTL_MODE_AUX);
+ return tegra_dpaux_pad_config(dpaux, DPAUX_PADCTL_FUNC_AUX);
}

int drm_dp_aux_disable(struct drm_dp_aux *aux)
--
2.1.4