From: Douglas Anderson <dianders@chromium.org>
To: Andrzej Hajda <a.hajda@samsung.com>,
Neil Armstrong <narmstrong@baylibre.com>,
Laurent Pinchart <Laurent.pinchart@ideasonboard.com>,
Jonas Karlman <jonas@kwiboo.se>,
Jernej Skrabec <jernej.skrabec@siol.net>,
Sam Ravnborg <sam@ravnborg.org>, Wolfram Sang <wsa@kernel.org>
Cc: linux-arm-msm@vger.kernel.org, robdclark@chromium.org,
Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>,
Stephen Boyd <swboyd@chromium.org>,
Steev Klimaszewski <steev@kali.org>,
Linus W <linus.walleij@linaro.org>,
Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
linux-i2c@vger.kernel.org,
Bjorn Andersson <bjorn.andersson@linaro.org>,
dri-devel@lists.freedesktop.org,
Douglas Anderson <dianders@chromium.org>,
Daniel Vetter <daniel@ffwll.ch>, David Airlie <airlied@linux.ie>,
Robert Foss <robert.foss@linaro.org>,
linux-kernel@vger.kernel.org
Subject: [PATCH v5 09/20] drm/bridge: ti-sn65dsi86: Break GPIO and MIPI-to-eDP bridge into sub-drivers
Date: Fri, 23 Apr 2021 09:58:55 -0700 [thread overview]
Message-ID: <20210423095743.v5.9.I3e68fa38c4ccbdbdf145cad2b01e83a1e5eac302@changeid> (raw)
In-Reply-To: <20210423165906.2504169-1-dianders@chromium.org>
Let's use the newly minted aux bus to break up the driver into sub
drivers. We're not doing a full breakup here: all the code is still in
the same file and remains largely untouched. The big goal here of
using sub-drivers is to allow part of our code to finish probing even
if some other code needs to defer. This can solve some chicken-and-egg
problems. Specifically:
- In commit 48834e6084f1 ("drm/panel-simple: Support hpd-gpios for
delaying prepare()") we had to add a bit of a hack to simpel-panel
to support HPD showing up late. We can get rid of that hack now
since the GPIO part of our driver can finish probing early.
- We have a desire to expose our DDC bus to simple-panel (and perhaps
to a backlight driver?). That will end up with the same
chicken-and-egg problem. A future patch to move this to a sub-driver
will fix it.
- If/when we support the PWM functionality present in the bridge chip
for a backlight we'll end up with another chicken-and-egg
problem. If we allow the PWM to be a sub-driver too then it solves
this problem.
Signed-off-by: Douglas Anderson <dianders@chromium.org>
---
Changes in v5:
- Fix module compile problems (Bjorn + kbuild bot)
- Remove useless MODULE_DEVICE_TABLE (Bjorn).
drivers/gpu/drm/bridge/Kconfig | 1 +
drivers/gpu/drm/bridge/ti-sn65dsi86.c | 252 ++++++++++++++++++++------
2 files changed, 200 insertions(+), 53 deletions(-)
diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
index d907a91a2ee8..bdec664f27ec 100644
--- a/drivers/gpu/drm/bridge/Kconfig
+++ b/drivers/gpu/drm/bridge/Kconfig
@@ -275,6 +275,7 @@ config DRM_TI_SN65DSI86
select REGMAP_I2C
select DRM_PANEL
select DRM_MIPI_DSI
+ select AUXILIARY_BUS
help
Texas Instruments SN65DSI86 DSI to eDP Bridge driver
diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c
index 68673f736b23..0bd1a1d1453e 100644
--- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c
+++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c
@@ -4,6 +4,7 @@
* datasheet: https://www.ti.com/lit/ds/symlink/sn65dsi86.pdf
*/
+#include <linux/auxiliary_bus.h>
#include <linux/bits.h>
#include <linux/clk.h>
#include <linux/debugfs.h>
@@ -113,7 +114,10 @@
/**
* struct ti_sn65dsi86 - Platform data for ti-sn65dsi86 driver.
- * @dev: Pointer to our device.
+ * @bridge_aux: AUX-bus sub device for MIPI-to-eDP bridge functionality.
+ * @gpio_aux: AUX-bus sub device for GPIO controller functionality.
+ *
+ * @dev: Pointer to the top level (i2c) device.
* @regmap: Regmap for accessing i2c.
* @aux: Our aux channel.
* @bridge: Our bridge.
@@ -140,6 +144,9 @@
* each other's read-modify-write.
*/
struct ti_sn65dsi86 {
+ struct auxiliary_device bridge_aux;
+ struct auxiliary_device gpio_aux;
+
struct device *dev;
struct regmap *regmap;
struct drm_dp_aux aux;
@@ -1136,8 +1143,10 @@ static const char * const ti_sn_bridge_gpio_names[SN_NUM_GPIOS] = {
"GPIO1", "GPIO2", "GPIO3", "GPIO4"
};
-static int ti_sn_setup_gpio_controller(struct ti_sn65dsi86 *pdata)
+static int ti_sn_gpio_probe(struct auxiliary_device *adev,
+ const struct auxiliary_device_id *id)
{
+ struct ti_sn65dsi86 *pdata = dev_get_drvdata(adev->dev.parent);
int ret;
/* Only init if someone is going to use us as a GPIO controller */
@@ -1159,20 +1168,41 @@ static int ti_sn_setup_gpio_controller(struct ti_sn65dsi86 *pdata)
pdata->gchip.names = ti_sn_bridge_gpio_names;
pdata->gchip.ngpio = SN_NUM_GPIOS;
pdata->gchip.base = -1;
- ret = devm_gpiochip_add_data(pdata->dev, &pdata->gchip, pdata);
+ ret = devm_gpiochip_add_data(&adev->dev, &pdata->gchip, pdata);
if (ret)
dev_err(pdata->dev, "can't add gpio chip\n");
return ret;
}
-#else
+static const struct auxiliary_device_id ti_sn_gpio_id_table[] = {
+ { .name = "ti_sn65dsi86.gpio", },
+ {},
+};
-static inline int ti_sn_setup_gpio_controller(struct ti_sn65dsi86 *pdata)
+MODULE_DEVICE_TABLE(auxiliary, ti_sn_gpio_id_table);
+
+static struct auxiliary_driver ti_sn_gpio_driver = {
+ .name = "gpio",
+ .probe = ti_sn_gpio_probe,
+ .id_table = ti_sn_gpio_id_table,
+};
+
+static int __init ti_sn_gpio_register(void)
{
- return 0;
+ return auxiliary_driver_register(&ti_sn_gpio_driver);
}
+static void __exit ti_sn_gpio_unregister(void)
+{
+ auxiliary_driver_unregister(&ti_sn_gpio_driver);
+}
+
+#else
+
+static inline int ti_sn_gpio_register(void) { return 0; }
+static inline void ti_sn_gpio_unregister(void) {}
+
#endif
static void ti_sn_bridge_parse_lanes(struct ti_sn65dsi86 *pdata,
@@ -1224,11 +1254,124 @@ static void ti_sn_bridge_parse_lanes(struct ti_sn65dsi86 *pdata,
pdata->ln_polrs = ln_polrs;
}
+static int ti_sn_bridge_probe(struct auxiliary_device *adev,
+ const struct auxiliary_device_id *id)
+{
+ struct ti_sn65dsi86 *pdata = dev_get_drvdata(adev->dev.parent);
+ struct device_node *np = pdata->dev->of_node;
+ int ret;
+
+ ret = drm_of_find_panel_or_bridge(np, 1, 0, &pdata->panel, NULL);
+ if (ret) {
+ DRM_ERROR("could not find any panel node\n");
+ return ret;
+ }
+
+ ti_sn_bridge_parse_lanes(pdata, np);
+
+ ret = ti_sn_bridge_parse_dsi_host(pdata);
+ if (ret)
+ return ret;
+
+ pdata->aux.name = "ti-sn65dsi86-aux";
+ pdata->aux.dev = pdata->dev;
+ pdata->aux.transfer = ti_sn_aux_transfer;
+ drm_dp_aux_init(&pdata->aux);
+
+ pdata->bridge.funcs = &ti_sn_bridge_funcs;
+ pdata->bridge.of_node = np;
+
+ drm_bridge_add(&pdata->bridge);
+
+ return 0;
+}
+
+static void ti_sn_bridge_remove(struct auxiliary_device *adev)
+{
+ struct ti_sn65dsi86 *pdata = dev_get_drvdata(adev->dev.parent);
+
+ if (!pdata)
+ return;
+
+ if (pdata->dsi) {
+ mipi_dsi_detach(pdata->dsi);
+ mipi_dsi_device_unregister(pdata->dsi);
+ }
+
+ kfree(pdata->edid);
+
+ drm_bridge_remove(&pdata->bridge);
+
+ of_node_put(pdata->host_node);
+}
+
+static const struct auxiliary_device_id ti_sn_bridge_id_table[] = {
+ { .name = "ti_sn65dsi86.bridge", },
+ {},
+};
+
+static struct auxiliary_driver ti_sn_bridge_driver = {
+ .name = "bridge",
+ .probe = ti_sn_bridge_probe,
+ .remove = ti_sn_bridge_remove,
+ .id_table = ti_sn_bridge_id_table,
+};
+
static void ti_sn65dsi86_runtime_disable(void *data)
{
pm_runtime_disable(data);
}
+static void ti_sn65dsi86_uninit_aux(void *data)
+{
+ auxiliary_device_uninit(data);
+}
+
+static void ti_sn65dsi86_delete_aux(void *data)
+{
+ auxiliary_device_delete(data);
+}
+
+/*
+ * AUX bus docs say that a non-NULL release is mandatory, but it makes no
+ * sense for the model used here where all of the aux devices are allocated
+ * in the single shared structure. We'll use this noop as a workaround.
+ */
+static void ti_sn65dsi86_noop(struct device *dev) {}
+
+static int ti_sn65dsi86_add_aux_device(struct ti_sn65dsi86 *pdata,
+ struct auxiliary_device *aux,
+ const char *name)
+{
+ struct device *dev = pdata->dev;
+ int ret;
+
+ /*
+ * NOTE: It would be nice to set the "of_node" of our children to be
+ * the same "of_node"" that the top-level component has. That doesn't
+ * work, though, since pinctrl will try (and fail) to reserve the
+ * pins again. Until that gets sorted out the children will just need
+ * to look at the of_node of the main device.
+ */
+
+ aux->name = name;
+ aux->dev.parent = dev;
+ aux->dev.release = ti_sn65dsi86_noop;
+ ret = auxiliary_device_init(aux);
+ if (ret)
+ return ret;
+ ret = devm_add_action_or_reset(dev, ti_sn65dsi86_uninit_aux, aux);
+ if (ret)
+ return ret;
+
+ ret = auxiliary_device_add(aux);
+ if (ret)
+ return ret;
+ ret = devm_add_action_or_reset(dev, ti_sn65dsi86_delete_aux, aux);
+
+ return ret;
+}
+
static int ti_sn65dsi86_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
@@ -1278,54 +1421,24 @@ static int ti_sn65dsi86_probe(struct i2c_client *client,
ti_sn65dsi86_debugfs_init(pdata);
- ret = drm_of_find_panel_or_bridge(dev->of_node, 1, 0, &pdata->panel, NULL);
- if (ret) {
- DRM_ERROR("could not find any panel node\n");
- return ret;
- }
-
- ti_sn_bridge_parse_lanes(pdata, dev->of_node);
-
- ret = ti_sn_bridge_parse_dsi_host(pdata);
- if (ret)
- return ret;
-
- ret = ti_sn_setup_gpio_controller(pdata);
- if (ret)
- return ret;
-
- pdata->aux.name = "ti-sn65dsi86-aux";
- pdata->aux.dev = dev;
- pdata->aux.transfer = ti_sn_aux_transfer;
- drm_dp_aux_init(&pdata->aux);
-
- pdata->bridge.funcs = &ti_sn_bridge_funcs;
- pdata->bridge.of_node = dev->of_node;
-
- drm_bridge_add(&pdata->bridge);
-
- return 0;
-}
-
-static int ti_sn65dsi86_remove(struct i2c_client *client)
-{
- struct ti_sn65dsi86 *pdata = i2c_get_clientdata(client);
-
- if (!pdata)
- return -EINVAL;
+ /*
+ * Break ourselves up into a collection of aux devices. The only real
+ * motiviation here is to solve the chicken-and-egg problem of probe
+ * ordering. The bridge wants the panel to be there when it probes.
+ * The panel wants its HPD GPIO (provided by sn65dsi86 on some boards)
+ * when it probes. There will soon be other devices (DDC I2C bus, PWM)
+ * that have the same problem. Having sub-devices allows the some sub
+ * devices to finish probing even if others return -EPROBE_DEFER and
+ * gets us around the problems.
+ */
- if (pdata->dsi) {
- mipi_dsi_detach(pdata->dsi);
- mipi_dsi_device_unregister(pdata->dsi);
+ if (IS_ENABLED(CONFIG_OF_GPIO)) {
+ ret = ti_sn65dsi86_add_aux_device(pdata, &pdata->gpio_aux, "gpio");
+ if (ret)
+ return ret;
}
- kfree(pdata->edid);
-
- drm_bridge_remove(&pdata->bridge);
-
- of_node_put(pdata->host_node);
-
- return 0;
+ return ti_sn65dsi86_add_aux_device(pdata, &pdata->bridge_aux, "bridge");
}
static struct i2c_device_id ti_sn65dsi86_id[] = {
@@ -1347,10 +1460,43 @@ static struct i2c_driver ti_sn65dsi86_driver = {
.pm = &ti_sn65dsi86_pm_ops,
},
.probe = ti_sn65dsi86_probe,
- .remove = ti_sn65dsi86_remove,
.id_table = ti_sn65dsi86_id,
};
-module_i2c_driver(ti_sn65dsi86_driver);
+
+static int __init ti_sn65dsi86_init(void)
+{
+ int ret;
+
+ ret = i2c_add_driver(&ti_sn65dsi86_driver);
+ if (ret)
+ return ret;
+
+ ret = ti_sn_gpio_register();
+ if (ret)
+ goto err_main_was_registered;
+
+ ret = auxiliary_driver_register(&ti_sn_bridge_driver);
+ if (ret)
+ goto err_gpio_was_registered;
+
+ return 0;
+
+err_gpio_was_registered:
+ ti_sn_gpio_unregister();
+err_main_was_registered:
+ i2c_del_driver(&ti_sn65dsi86_driver);
+
+ return ret;
+}
+module_init(ti_sn65dsi86_init);
+
+static void __exit ti_sn65dsi86_exit(void)
+{
+ auxiliary_driver_unregister(&ti_sn_bridge_driver);
+ ti_sn_gpio_unregister();
+ i2c_del_driver(&ti_sn65dsi86_driver);
+}
+module_exit(ti_sn65dsi86_exit);
MODULE_AUTHOR("Sandeep Panda <spanda@codeaurora.org>");
MODULE_DESCRIPTION("sn65dsi86 DSI to eDP bridge driver");
--
2.31.1.498.g6c1eba8ee3d-goog
next prev parent reply other threads:[~2021-04-23 16:59 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-23 16:58 [PATCH v5 00/20] drm: Fix EDID reading on ti-sn65dsi86; solve some chicken-and-egg problems Douglas Anderson
2021-04-23 16:58 ` [PATCH v5 01/20] drm/panel: panel-simple: Add missing pm_runtime_disable() calls Douglas Anderson
2021-04-28 16:32 ` Sean Paul
2021-04-30 0:58 ` Linus Walleij
2021-04-30 1:24 ` Doug Anderson
2021-04-30 1:27 ` Linus Walleij
2021-04-30 21:04 ` Doug Anderson
2021-05-01 12:07 ` Linus Walleij
2021-05-03 20:41 ` Doug Anderson
2021-05-05 12:51 ` Linus Walleij
2021-04-23 16:58 ` [PATCH v5 02/20] drm/bridge: ti-sn65dsi86: Rename the main driver data structure Douglas Anderson
2021-04-23 16:58 ` [PATCH v5 03/20] drm/bridge: ti-sn65dsi86: More renames in prep for sub-devices Douglas Anderson
2021-04-23 16:58 ` [PATCH v5 04/20] drm/bridge: ti-sn65dsi86: Use devm to do our runtime_disable Douglas Anderson
2021-04-23 16:58 ` [PATCH v5 05/20] drm/bridge: ti-sn65dsi86: Clean debugfs code Douglas Anderson
2021-04-23 16:58 ` [PATCH v5 06/20] drm/bridge: ti-sn65dsi86: Add local var for "dev" to simplify probe Douglas Anderson
2021-04-23 16:58 ` [PATCH v5 07/20] drm/bridge: ti-sn65dsi86: Cleanup managing of drvdata Douglas Anderson
2021-04-23 16:58 ` [PATCH v5 08/20] drm/bridge: ti-sn65dsi86: Move all the chip-related init to the start Douglas Anderson
2021-04-23 16:58 ` Douglas Anderson [this message]
2021-05-01 11:59 ` [PATCH v5 09/20] drm/bridge: ti-sn65dsi86: Break GPIO and MIPI-to-eDP bridge into sub-drivers Linus Walleij
2021-05-03 16:55 ` Doug Anderson
2021-04-23 16:58 ` [PATCH v5 10/20] drm/panel: panel-simple: Get rid of hacky HPD chicken-and-egg code Douglas Anderson
2021-04-28 16:35 ` Sean Paul
2021-04-23 16:58 ` [PATCH v5 11/20] drm/bridge: ti-sn65dsi86: Use pm_runtime autosuspend Douglas Anderson
2021-04-23 16:58 ` [PATCH v5 12/20] drm/bridge: ti-sn65dsi86: Code motion of refclk management functions Douglas Anderson
2021-04-23 16:58 ` [PATCH v5 13/20] drm/bridge: ti-sn65dsi86: If refclk, DP AUX can happen w/out pre-enable Douglas Anderson
2021-04-23 16:59 ` [PATCH v5 14/20] drm/bridge: ti-sn65dsi86: Promote the AUX channel to its own sub-dev Douglas Anderson
2021-05-03 20:27 ` Doug Anderson
2021-04-23 16:59 ` [PATCH v5 15/20] i2c: i2c-core-of: Fix corner case of finding adapter by node Douglas Anderson
2021-04-23 16:59 ` [PATCH v5 16/20] drm/panel: panel-simple: Remove extra call: drm_connector_update_edid_property() Douglas Anderson
2021-04-28 16:38 ` Sean Paul
2021-04-23 16:59 ` [PATCH v5 17/20] drm/panel: panel-simple: Power the panel when reading the EDID Douglas Anderson
2021-04-28 16:44 ` Sean Paul
2021-04-23 16:59 ` [PATCH v5 18/20] drm/panel: panel-simple: Cache the EDID as long as we retain power Douglas Anderson
2021-04-28 16:50 ` Sean Paul
2021-04-23 16:59 ` [PATCH v5 19/20] drm/bridge: ti-sn65dsi86: Don't read EDID blob over DDC Douglas Anderson
2021-04-23 16:59 ` [PATCH v5 20/20] arm64: dts: qcom: Link the panel to the bridge's DDC bus Douglas Anderson
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