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");