[PATCH v2 1/2] drm: bridge: sil902x

Boris Brezillon
2016-01-06T12:25:26Z

Add basic support for the sil902x RGB -> HDMI bridge.
This driver does not support audio output yet.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
---
Hello,

This patch is only adding basic support for the sil9022 chip.
As stated in the commit log, there's no audio support, but the
driver also hardcodes a lot of things (like the RGB input format to
use).
There are two reasons for this:
1/ the DRM framework does not allow for advanced link description
between an encoder and a bridge (that's for the RGB format
limitation). Any idea how this should be described?

2/ I don't have the datasheet of this HDMI encoder, and all logic
has been extracted from those two drivers [1][2], which means
I may miss some important things in my encoder setup.

Another thing I find weird in the drm_bridge interface is the fact
that we have a ->attach() method, but no ->detach(), which can be
a problem if we allow drm bridges and KMS drivers to be compiled as
modules. Any reason for that?

That's all for the questions part :-).

Best Regards,

Boris

Changes in v2:
- fix errors reported by kbuild test robot

---
drivers/gpu/drm/bridge/Kconfig | 8 +
drivers/gpu/drm/bridge/Makefile | 1 +
drivers/gpu/drm/bridge/sil902x.c | 491 +++++++++++++++++++++++++++++++++++++++
3 files changed, 500 insertions(+)
create mode 100644 drivers/gpu/drm/bridge/sil902x.c

diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
index 27e2022..9701fd2 100644
--- a/drivers/gpu/drm/bridge/Kconfig
+++ b/drivers/gpu/drm/bridge/Kconfig
@@ -40,4 +40,12 @@ config DRM_PARADE_PS8622
---help---
Parade eDP-LVDS bridge chip driver.

+config DRM_SIL902X
+ tristate "Silicon Image sil902x RGB/HDMI bridge"
+ depends on OF
+ select DRM_KMS_HELPER
+ select REGMAP_I2C
+ ---help---
+ Silicon Image sil902x bridge chip driver.
+
endmenu
diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile
index f13c33d..a689aad 100644
--- a/drivers/gpu/drm/bridge/Makefile
+++ b/drivers/gpu/drm/bridge/Makefile
@@ -4,3 +4,4 @@ obj-$(CONFIG_DRM_DW_HDMI) += dw-hdmi.o
obj-$(CONFIG_DRM_DW_HDMI_AHB_AUDIO) += dw-hdmi-ahb-audio.o
obj-$(CONFIG_DRM_NXP_PTN3460) += nxp-ptn3460.o
obj-$(CONFIG_DRM_PARADE_PS8622) += parade-ps8622.o
+obj-$(CONFIG_DRM_SIL902X) += sil902x.o
diff --git a/drivers/gpu/drm/bridge/sil902x.c b/drivers/gpu/drm/bridge/sil902x.c
new file mode 100644
index 0000000..2657031
--- /dev/null
+++ b/drivers/gpu/drm/bridge/sil902x.c
@@ -0,0 +1,491 @@
+/*
+ * Copyright (C) 2014 Atmel
+ * Bo Shen <voice.shen@atmel.com>
+ *
+ * Authors: Bo Shen <voice.shen@atmel.com>
+ * Boris Brezillon <boris.brezillon@free-electrons.com>
+ * Wu, Songjun <Songjun.Wu@atmel.com>
+ *
+ *
+ * Copyright (C) 2010-2011 Freescale Semiconductor, Inc. All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/component.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
+#include <linux/regmap.h>
+
+#include <drm/drmP.h>
+#include <drm/drm_atomic.h>
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_crtc_helper.h>
+#include <drm/drm_edid.h>
+#include <drm/drm_encoder_slave.h>
+
+#define SIL902X_TPI_VIDEO_DATA 0x0
+
+#define SIL902X_TPI_PIXEL_REPETITION 0x8
+#define SIL902X_TPI_AVI_PIXEL_REP_BUS_24BIT BIT(5)
+#define SIL902X_TPI_AVI_PIXEL_REP_RISING_EDGE BIT(4)
+#define SIL902X_TPI_AVI_PIXEL_REP_4X 3
+#define SIL902X_TPI_AVI_PIXEL_REP_2X 1
+#define SIL902X_TPI_AVI_PIXEL_REP_NONE 0
+#define SIL902X_TPI_CLK_RATIO_HALF (0 << 6)
+#define SIL902X_TPI_CLK_RATIO_1X (1 << 6)
+#define SIL902X_TPI_CLK_RATIO_2X (2 << 6)
+#define SIL902X_TPI_CLK_RATIO_4X (3 << 6)
+
+#define SIL902X_TPI_AVI_IN_FORMAT 0x9
+#define SIL902X_TPI_AVI_INPUT_BITMODE_12BIT BIT(7)
+#define SIL902X_TPI_AVI_INPUT_DITHER BIT(6)
+#define SIL902X_TPI_AVI_INPUT_RANGE_LIMITED (2 << 2)
+#define SIL902X_TPI_AVI_INPUT_RANGE_FULL (1 << 2)
+#define SIL902X_TPI_AVI_INPUT_RANGE_AUTO (0 << 2)
+#define SIL902X_TPI_AVI_INPUT_COLORSPACE_BLACK (3 << 0)
+#define SIL902X_TPI_AVI_INPUT_COLORSPACE_YUV422 (2 << 0)
+#define SIL902X_TPI_AVI_INPUT_COLORSPACE_YUV444 (1 << 0)
+#define SIL902X_TPI_AVI_INPUT_COLORSPACE_RGB (0 << 0)
+
+#define SIL902X_TPI_AVI_INFOFRAME 0x0c
+
+#define SIL902X_SYS_CTRL_DATA 0x1a
+#define SIL902X_SYS_CTRL_PWR_DWN BIT(4)
+#define SIL902X_SYS_CTRL_AV_MUTE BIT(3)
+#define SIL902X_SYS_CTRL_DDC_BUS_REQ BIT(2)
+#define SIL902X_SYS_CTRL_DDC_BUS_GRTD BIT(1)
+#define SIL902X_SYS_CTRL_OUTPUT_MODE BIT(0)
+#define SIL902X_SYS_CTRL_OUTPUT_HDMI 1
+#define SIL902X_SYS_CTRL_OUTPUT_DVI 0
+
+#define SIL902X_REG_CHIPID(n) (0x1b + (n))
+
+#define SIL902X_PWR_STATE_CTRL 0x1e
+#define SIL902X_AVI_POWER_STATE_MSK GENMASK(1, 0)
+#define SIL902X_AVI_POWER_STATE_D(l) ((l) & SIL902X_AVI_POWER_STATE_MSK)
+
+#define SI902X_INT_ENABLE 0x3c
+#define SI902X_INT_STATUS 0x3d
+#define SI902X_HOTPLUG_EVENT BIT(0)
+#define SI902X_PLUGGED_STATUS BIT(2)
+
+#define SIL902X_REG_TPI_RQB 0xc7
+
+struct sil902x {
+ struct i2c_client *i2c;
+ struct regmap *regmap;
+ struct drm_bridge bridge;
+ struct drm_connector connector;
+ struct gpio_desc *reset_gpio;
+ struct work_struct hotplug_work;
+};
+
+static inline struct sil902x *bridge_to_sil902x(struct drm_bridge *bridge)
+{
+ return container_of(bridge, struct sil902x, bridge);
+}
+
+static inline struct sil902x *connector_to_sil902x(struct drm_connector *con)
+{
+ return container_of(con, struct sil902x, connector);
+}
+
+static void sil902x_reset(struct sil902x *sil902x)
+{
+ gpiod_set_value(sil902x->reset_gpio, 1);
+
+ msleep(100);
+
+ gpiod_set_value(sil902x->reset_gpio, 0);
+}
+
+static void sil902x_connector_destroy(struct drm_connector *connector)
+{
+ drm_connector_unregister(connector);
+ drm_connector_cleanup(connector);
+}
+
+static enum drm_connector_status
+sil902x_connector_detect(struct drm_connector *connector, bool force)
+{
+ struct sil902x *sil902x = connector_to_sil902x(connector);
+ unsigned int status;
+
+ regmap_read(sil902x->regmap, SI902X_INT_STATUS, &status);
+
+ return (status & SI902X_PLUGGED_STATUS) ?
+ connector_status_connected : connector_status_disconnected;
+}
+
+static const struct drm_connector_funcs sil902x_atomic_connector_funcs = {
+ .dpms = drm_atomic_helper_connector_dpms,
+ .detect = sil902x_connector_detect,
+ .fill_modes = drm_helper_probe_single_connector_modes,
+ .destroy = sil902x_connector_destroy,
+ .reset = drm_atomic_helper_connector_reset,
+ .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
+ .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
+};
+
+static const struct drm_connector_funcs sil902x_connector_funcs = {
+ .dpms = drm_atomic_helper_connector_dpms,
+ .detect = sil902x_connector_detect,
+ .fill_modes = drm_helper_probe_single_connector_modes,
+ .destroy = sil902x_connector_destroy,
+};
+
+static int sil902x_get_modes(struct drm_connector *connector)
+{
+ struct sil902x *sil902x = connector_to_sil902x(connector);
+ struct regmap *regmap = sil902x->regmap;
+ u32 bus_format = MEDIA_BUS_FMT_RGB888_1X24;
+ unsigned int status;
+ struct edid *edid;
+ int num = 0;
+ int ret;
+ int i;
+
+ ret = regmap_update_bits(regmap, SIL902X_PWR_STATE_CTRL,
+ SIL902X_AVI_POWER_STATE_MSK,
+ SIL902X_AVI_POWER_STATE_D(2));
+ if (ret)
+ return ret;
+
+ ret = regmap_write(regmap, SIL902X_SYS_CTRL_DATA,
+ SIL902X_SYS_CTRL_OUTPUT_HDMI |
+ SIL902X_SYS_CTRL_PWR_DWN);
+ if (ret)
+ return ret;
+
+ ret = regmap_update_bits(regmap, SIL902X_SYS_CTRL_DATA,
+ SIL902X_SYS_CTRL_DDC_BUS_REQ,
+ SIL902X_SYS_CTRL_DDC_BUS_REQ);
+ if (ret)
+ return ret;
+
+ i = 0;
+ do {
+ ret = regmap_read(regmap, SIL902X_SYS_CTRL_DATA, &status);
+ if (ret)
+ return ret;
+ i++;
+ } while (!(status & SIL902X_SYS_CTRL_DDC_BUS_GRTD));
+
+ ret = regmap_write(regmap, SIL902X_SYS_CTRL_DATA, status);
+ if (ret)
+ return ret;
+
+ edid = drm_get_edid(connector, sil902x->i2c->adapter);
+ drm_mode_connector_update_edid_property(connector, edid);
+ if (edid) {
+ num += drm_add_edid_modes(connector, edid);
+ kfree(edid);
+ }
+
+ ret = drm_display_info_set_bus_formats(&connector->display_info,
+ &bus_format, 1);
+ if (ret)
+ return ret;
+
+ regmap_read(regmap, SIL902X_SYS_CTRL_DATA, &status);
+ if (ret)
+ return ret;
+
+ ret = regmap_update_bits(regmap, SIL902X_SYS_CTRL_DATA,
+ SIL902X_SYS_CTRL_DDC_BUS_REQ |
+ SIL902X_SYS_CTRL_DDC_BUS_GRTD, 0);
+ if (ret)
+ return ret;
+
+ i = 0;
+ do {
+ ret = regmap_read(regmap, SIL902X_SYS_CTRL_DATA, &status);
+ if (ret)
+ return ret;
+ i++;
+ } while (status & (SIL902X_SYS_CTRL_DDC_BUS_REQ |
+ SIL902X_SYS_CTRL_DDC_BUS_GRTD));
+
+ return num;
+}
+
+static enum drm_mode_status sil902x_mode_valid(struct drm_connector *connector,
+ struct drm_display_mode *mode)
+{
+ /* TODO: check mode */
+
+ return MODE_OK;
+}
+
+static struct drm_encoder *sil902x_best_encoder(struct drm_connector *connector)
+{
+ struct sil902x *sil902x = connector_to_sil902x(connector);
+
+ return sil902x->bridge.encoder;
+}
+
+static const struct drm_connector_helper_funcs sil902x_connector_helper_funcs = {
+ .get_modes = sil902x_get_modes,
+ .mode_valid = sil902x_mode_valid,
+ .best_encoder = sil902x_best_encoder,
+};
+
+static void sil902x_bridge_disable(struct drm_bridge *bridge)
+{
+ struct sil902x *sil902x = bridge_to_sil902x(bridge);
+
+ regmap_update_bits(sil902x->regmap, SIL902X_SYS_CTRL_DATA,
+ SIL902X_SYS_CTRL_PWR_DWN,
+ SIL902X_SYS_CTRL_PWR_DWN);
+}
+
+static void sil902x_bridge_enable(struct drm_bridge *bridge)
+{
+ struct sil902x *sil902x = bridge_to_sil902x(bridge);
+
+ regmap_update_bits(sil902x->regmap, SIL902X_PWR_STATE_CTRL,
+ SIL902X_AVI_POWER_STATE_MSK,
+ SIL902X_AVI_POWER_STATE_D(0));
+ regmap_update_bits(sil902x->regmap, SIL902X_SYS_CTRL_DATA,
+ SIL902X_SYS_CTRL_PWR_DWN, 0);
+}
+
+static void sil902x_bridge_mode_set(struct drm_bridge *bridge,
+ struct drm_display_mode *mode,
+ struct drm_display_mode *adj)
+{
+ u8 buf[HDMI_INFOFRAME_HEADER_SIZE + HDMI_AVI_INFOFRAME_SIZE];
+ struct sil902x *sil902x = bridge_to_sil902x(bridge);
+ struct regmap *regmap = sil902x->regmap;
+ struct hdmi_avi_infoframe frame;
+ int ret;
+
+ buf[0] = adj->clock;
+ buf[1] = adj->clock >> 8;
+ buf[2] = adj->vrefresh;
+ buf[3] = 0x00;
+ buf[4] = adj->hdisplay;
+ buf[5] = adj->hdisplay >> 8;
+ buf[6] = adj->vdisplay;
+ buf[7] = adj->vdisplay >> 8;
+ buf[8] = SIL902X_TPI_CLK_RATIO_1X | SIL902X_TPI_AVI_PIXEL_REP_NONE |
+ SIL902X_TPI_AVI_PIXEL_REP_BUS_24BIT;
+ buf[9] = SIL902X_TPI_AVI_INPUT_RANGE_AUTO |
+ SIL902X_TPI_AVI_INPUT_COLORSPACE_RGB;
+
+ ret = regmap_bulk_write(regmap, SIL902X_TPI_VIDEO_DATA, buf, 10);
+ if (ret)
+ return;
+
+ ret = drm_hdmi_avi_infoframe_from_display_mode(&frame, adj);
+ if (ret < 0) {
+ DRM_ERROR("couldn't fill AVI infoframe\n");
+ return;
+ }
+
+ ret = hdmi_avi_infoframe_pack(&frame, buf, sizeof(buf));
+ if (ret < 0) {
+ DRM_ERROR("failed to pack AVI infoframe: %zd\n", ret);
+ return;
+ }
+
+ /* Do not send the infoframe header, but keep the CRC field. */
+ regmap_bulk_write(regmap, SIL902X_TPI_AVI_INFOFRAME,
+ buf + HDMI_INFOFRAME_HEADER_SIZE - 1,
+ HDMI_AVI_INFOFRAME_SIZE + 1);
+}
+
+static int sil902x_bridge_attach(struct drm_bridge *bridge)
+{
+ const struct drm_connector_funcs *funcs = &sil902x_connector_funcs;
+ struct sil902x *sil902x = bridge_to_sil902x(bridge);
+ struct drm_device *drm = bridge->dev;
+ int ret;
+
+ drm_connector_helper_add(&sil902x->connector,
+ &sil902x_connector_helper_funcs);
+
+ if (drm_core_check_feature(drm, DRIVER_ATOMIC))
+ funcs = &sil902x_atomic_connector_funcs;
+
+ ret = drm_connector_init(drm, &sil902x->connector, funcs,
+ DRM_MODE_CONNECTOR_HDMIA);
+ if (ret)
+ return ret;
+
+ if (sil902x->i2c->irq > 0)
+ sil902x->connector.polled = DRM_CONNECTOR_POLL_HPD;
+ else
+ sil902x->connector.polled = DRM_CONNECTOR_POLL_CONNECT;
+
+ drm_mode_connector_attach_encoder(&sil902x->connector, bridge->encoder);
+
+ return 0;
+}
+
+static void sil902x_bridge_nop(struct drm_bridge *bridge)
+{
+}
+
+static const struct drm_bridge_funcs sil902x_bridge_funcs = {
+ .attach = sil902x_bridge_attach,
+ .mode_set = sil902x_bridge_mode_set,
+ .disable = sil902x_bridge_disable,
+ .post_disable = sil902x_bridge_nop,
+ .pre_enable = sil902x_bridge_nop,
+ .enable = sil902x_bridge_enable,
+};
+
+static const struct regmap_range sil902x_volatile_ranges[] = {
+ { .range_min = 0, .range_max = 0xff },
+};
+
+static const struct regmap_access_table sil902x_volatile_table = {
+ .yes_ranges = sil902x_volatile_ranges,
+ .n_yes_ranges = ARRAY_SIZE(sil902x_volatile_ranges),
+};
+
+static const struct regmap_config sil902x_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 8,
+ .volatile_table = &sil902x_volatile_table,
+ .cache_type = REGCACHE_NONE,
+};
+
+static irqreturn_t sil902x_interrupt(int irq, void *data)
+{
+ struct sil902x *sil902x = data;
+ unsigned int status = 0;
+
+ regmap_read(sil902x->regmap, SI902X_INT_STATUS, &status);
+ regmap_write(sil902x->regmap, SI902X_INT_STATUS, status);
+
+ if ((status & SI902X_HOTPLUG_EVENT) && sil902x->bridge.dev)
+ drm_helper_hpd_irq_event(sil902x->bridge.dev);
+
+ return IRQ_HANDLED;
+}
+
+static int sil902x_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct device *dev = &client->dev;
+ unsigned int status = 0;
+ struct sil902x *sil902x;
+ u8 chipid[4];
+ int ret;
+
+ sil902x = devm_kzalloc(dev, sizeof(*sil902x), GFP_KERNEL);
+ if (!sil902x)
+ return -ENOMEM;
+
+ sil902x->i2c = client;
+ sil902x->regmap = devm_regmap_init_i2c(client, &sil902x_regmap_config);
+ if (IS_ERR(sil902x->regmap))
+ return PTR_ERR(sil902x->regmap);
+
+ sil902x->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
+ if (IS_ERR(sil902x->reset_gpio)) {
+ dev_err(dev, "Failed to retrieve/request reset gpio: %ld\n",
+ PTR_ERR(sil902x->reset_gpio));
+ return PTR_ERR(sil902x->reset_gpio);
+ }
+
+ sil902x_reset(sil902x);
+
+ ret = regmap_write(sil902x->regmap, SIL902X_REG_TPI_RQB, 0x0);
+ if (ret)
+ return ret;
+
+ ret = regmap_bulk_read(sil902x->regmap, SIL902X_REG_CHIPID(0),
+ &chipid, 4);
+ if (ret) {
+ dev_err(dev, "regmap_read failed %d\n", ret);
+ return ret;
+ }
+
+ if (chipid[0] != 0xb0) {
+ dev_err(dev, "Invalid chipid: %02x (expecting 0xb0)\n",
+ chipid[0]);
+ return -EINVAL;
+ }
+
+ /* Clear all pending interrupts */
+ regmap_read(sil902x->regmap, SI902X_INT_STATUS, &status);
+ regmap_write(sil902x->regmap, SI902X_INT_STATUS, status);
+
+ if (client->irq > 0) {
+ regmap_write(sil902x->regmap, SI902X_INT_ENABLE,
+ SI902X_HOTPLUG_EVENT);
+
+ ret = devm_request_threaded_irq(dev, client->irq, NULL,
+ sil902x_interrupt,
+ IRQF_ONESHOT, dev_name(dev),
+ sil902x);
+ if (ret)
+ return ret;
+ }
+
+ sil902x->bridge.funcs = &sil902x_bridge_funcs;
+ sil902x->bridge.of_node = dev->of_node;
+ ret = drm_bridge_add(&sil902x->bridge);
+ if (ret) {
+ dev_err(dev, "Failed to add drm_bridge\n");
+ return ret;
+ }
+
+ i2c_set_clientdata(client, sil902x);
+
+ return 0;
+}
+
+static int sil902x_remove(struct i2c_client *client)
+
+{
+ struct sil902x *sil902x = i2c_get_clientdata(client);
+
+ drm_bridge_remove(&sil902x->bridge);
+
+ return 0;
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id sil902x_dt_ids[] = {
+ { .compatible = "sil,sil9022", },
+ { }
+};
+MODULE_DEVICE_TABLE(of, sil902x_dt_ids);
+#endif
+
+static const struct i2c_device_id sil902x_i2c_ids[] = {
+ { "sil9022", 0 },
+ { },
+};
+MODULE_DEVICE_TABLE(i2c, sil902x_i2c_ids);
+
+static struct i2c_driver sil902x_driver = {
+ .probe = sil902x_probe,
+ .remove = sil902x_remove,
+ .driver = {
+ .name = "sil902x",
+ .of_match_table = of_match_ptr(sil902x_dt_ids),
+ },
+ .id_table = sil902x_i2c_ids,
+};
+module_i2c_driver(sil902x_driver);
+
+MODULE_AUTHOR("Boris Brezillon <boris.brezillon@free-electrons.com>");
+MODULE_DESCRIPTION("SIL902x RGB -> HDMI bridges");
+MODULE_LICENSE("GPL");
--
2.1.4