[PATCH drm/hisilicon 1/3] drm/hisilicon: Support i2c driver algorithms for bit-shift adapters

From: Tian Tao
Date: Sun Sep 20 2020 - 23:28:10 EST


Adding driver implementation to support i2c driver algorithms for
bit-shift adapters, so hibmc will using the interface provided by
drm to read edid.

Signed-off-by: Tian Tao <tiantao6@xxxxxxxxxxxxx>
---
drivers/gpu/drm/hisilicon/hibmc/Makefile | 2 +-
drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.h | 21 +++++-
drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_i2c.c | 98 +++++++++++++++++++++++++
3 files changed, 119 insertions(+), 2 deletions(-)
create mode 100644 drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_i2c.c

diff --git a/drivers/gpu/drm/hisilicon/hibmc/Makefile b/drivers/gpu/drm/hisilicon/hibmc/Makefile
index f991327..684ef79 100644
--- a/drivers/gpu/drm/hisilicon/hibmc/Makefile
+++ b/drivers/gpu/drm/hisilicon/hibmc/Makefile
@@ -1,4 +1,4 @@
# SPDX-License-Identifier: GPL-2.0-only
-hibmc-drm-y := hibmc_drm_drv.o hibmc_drm_de.o hibmc_drm_vdac.o hibmc_ttm.o
+hibmc-drm-y := hibmc_drm_drv.o hibmc_drm_de.o hibmc_drm_vdac.o hibmc_ttm.o hibmc_drm_i2c.o

obj-$(CONFIG_DRM_HISI_HIBMC) += hibmc-drm.o
diff --git a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.h b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.h
index 197485e..1b2edb3 100644
--- a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.h
+++ b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.h
@@ -14,11 +14,24 @@
#ifndef HIBMC_DRM_DRV_H
#define HIBMC_DRM_DRV_H

+#include <linux/gpio/consumer.h>
+#include <linux/i2c-algo-bit.h>
+#include <linux/i2c.h>
+
+#include <drm/drm_edid.h>
#include <drm/drm_fb_helper.h>
#include <drm/drm_framebuffer.h>

struct drm_device;

+struct hibmc_connector {
+ struct drm_connector base;
+ struct drm_device *dev;
+
+ struct i2c_adapter adapter;
+ struct i2c_algo_bit_data bit_data;
+};
+
struct hibmc_drm_private {
/* hw */
void __iomem *mmio;
@@ -31,10 +44,15 @@ struct hibmc_drm_private {
struct drm_plane primary_plane;
struct drm_crtc crtc;
struct drm_encoder encoder;
- struct drm_connector connector;
+ struct hibmc_connector connector;
bool mode_config_initialized;
};

+static inline struct hibmc_connector *to_hibmc_connector(struct drm_connector *connector)
+{
+ return container_of(connector, struct hibmc_connector, base);
+}
+
void hibmc_set_power_mode(struct hibmc_drm_private *priv,
unsigned int power_mode);
void hibmc_set_current_gate(struct hibmc_drm_private *priv,
@@ -47,6 +65,7 @@ int hibmc_mm_init(struct hibmc_drm_private *hibmc);
void hibmc_mm_fini(struct hibmc_drm_private *hibmc);
int hibmc_dumb_create(struct drm_file *file, struct drm_device *dev,
struct drm_mode_create_dumb *args);
+int hibmc_ddc_create(struct hibmc_connector *connector);

extern const struct drm_mode_config_funcs hibmc_mode_funcs;

diff --git a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_i2c.c b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_i2c.c
new file mode 100644
index 0000000..0506846
--- /dev/null
+++ b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_i2c.c
@@ -0,0 +1,98 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Hisilicon Hibmc SoC drm driver
+ *
+ * Based on the bochs drm driver.
+ *
+ * Copyright (c) 2016 Huawei Limited.
+ *
+ * Author:
+ * Tian Tao <tiantao6@xxxxxxxxxxxxx>
+ */
+
+#include <linux/delay.h>
+#include <linux/pci.h>
+
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_probe_helper.h>
+
+#include "hibmc_drm_drv.h"
+
+#define GPIO_DATA 0x0802A0
+#define GPIO_DATA_DIRECTION 0x0802A4
+
+#define GPIO_SCL_MASK 0x1
+#define GPIO_SDA_MASK 0x2
+
+static void hibmc_set_i2c_signal(void *data, u32 mask, int value)
+{
+ struct hibmc_connector *hibmc_connector = data;
+ struct hibmc_drm_private *priv = hibmc_connector->dev->dev_private;
+ u32 tmp_dir = readl(priv->mmio + GPIO_DATA_DIRECTION);
+
+ if (value) {
+ tmp_dir &= ~mask;
+ writel(tmp_dir, priv->mmio + GPIO_DATA_DIRECTION);
+ } else {
+ u32 tmp_data = readl(priv->mmio + GPIO_DATA);
+
+ tmp_data &= ~mask;
+ writel(tmp_data, priv->mmio + GPIO_DATA);
+
+ tmp_dir |= mask;
+ writel(tmp_dir, priv->mmio + GPIO_DATA_DIRECTION);
+ }
+}
+
+static int hibmc_get_i2c_signal(void *data, u32 mask)
+{
+ struct hibmc_connector *hibmc_connector = data;
+ struct hibmc_drm_private *priv = hibmc_connector->dev->dev_private;
+ u32 tmp_dir = readl(priv->mmio + GPIO_DATA_DIRECTION);
+
+ if ((tmp_dir & mask) != mask) {
+ tmp_dir &= ~mask;
+ writel(tmp_dir, priv->mmio + GPIO_DATA_DIRECTION);
+ }
+
+ return (readl(priv->mmio + GPIO_DATA) & mask) ? 1 : 0;
+}
+
+static void hibmc_ddc_setsda(void *data, int state)
+{
+ hibmc_set_i2c_signal(data, GPIO_SDA_MASK, state);
+}
+
+static void hibmc_ddc_setscl(void *data, int state)
+{
+ hibmc_set_i2c_signal(data, GPIO_SCL_MASK, state);
+}
+
+static int hibmc_ddc_getsda(void *data)
+{
+ return hibmc_get_i2c_signal(data, GPIO_SDA_MASK);
+}
+
+static int hibmc_ddc_getscl(void *data)
+{
+ return hibmc_get_i2c_signal(data, GPIO_SCL_MASK);
+}
+
+int hibmc_ddc_create(struct hibmc_connector *connector)
+{
+ connector->adapter.owner = THIS_MODULE;
+ connector->adapter.class = I2C_CLASS_DDC;
+ snprintf(connector->adapter.name, I2C_NAME_SIZE, "HIS i2c bit bus");
+ connector->adapter.dev.parent = &connector->dev->pdev->dev;
+ i2c_set_adapdata(&connector->adapter, connector);
+ connector->adapter.algo_data = &connector->bit_data;
+
+ connector->bit_data.udelay = 20;
+ connector->bit_data.timeout = usecs_to_jiffies(2000);
+ connector->bit_data.data = connector;
+ connector->bit_data.setsda = hibmc_ddc_setsda;
+ connector->bit_data.setscl = hibmc_ddc_setscl;
+ connector->bit_data.getsda = hibmc_ddc_getsda;
+ connector->bit_data.getscl = hibmc_ddc_getscl;
+
+ return i2c_bit_add_bus(&connector->adapter);
+}
--
2.7.4