Re: [PATCH v2 1/2] drm: bridge: sil902x
From: Archit Taneja
Date: Thu Jan 07 2016 - 00:43:07 EST
On 01/06/2016 05:55 PM, Boris Brezillon wrote:
Add basic support for the sil902x RGB -> HDMI bridge.
This driver does not support audio output yet.
Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxxxxxxx>
---
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?
The adv7511 driver uses a DT param "input_colorspace" to chose between
RGB or YUV. I don't think DT is the best idea, but I don't know of a
better way either.
The connector's display_info.color_formats field gives us some info
about the color formats supported by the monitor, but I guess that
isn't sufficient data to know what format the encoder is pushing out.
We get around this problem in case the case of DSI encoders by using
the mipi_dsi_device api, where a DSI based bridge or panel can pass
color format/lane info to the DSI host (i.e, encoder) by using
mipi_dsi_attach().
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?
I guess the drm_bridge_add/remove ops make can ensure that the bridge
driver itself can be compiled as a module. However, you're right that
we would need a bridge detach op that the kms driver should call
before it is removed (to unregister the connector we created).
Someone would still need to make sure about the order in which the
modules are removed. If the bridge driver is removed first, then
it would really mess up the kms driver using the bridge.
Would the kms driver using this chip really have an encoder?
Since the chip takes in RGB input, I'm assuming that the encoder in
the kms driver would more or less be nop funcs, giving their way to
bridge ops.
In such cases, I think the bridge still doesn't fit in so well. The
best fit here is how the current tda998x driver is modeled. It adds
itself as a component that creates both an encoder and connector,
which the kms driver can use directly. This approach, of course,
prevents us using tda998x in kms drivers that don't accept any
encoders that it didn't create itself.
Thanks,
Archit
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@xxxxxxxxx>
+ *
+ * Authors: Bo Shen <voice.shen@xxxxxxxxx>
+ * Boris Brezillon <boris.brezillon@xxxxxxxxxxxxxxxxxx>
+ * Wu, Songjun <Songjun.Wu@xxxxxxxxx>
+ *
+ *
+ * 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@xxxxxxxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("SIL902x RGB -> HDMI bridges");
+MODULE_LICENSE("GPL");
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