Re: [PATCH v3 25/56] drm/omap: dsi: move TE GPIO handling into core

Tomi Valkeinen
2020-11-11T13:27:05Z

On 09/11/2020 11:19, Laurent Pinchart wrote:
> Hi Tomi and Sebastian,
>
> Thank you for the patch.
>
> On Thu, Nov 05, 2020 at 02:03:02PM +0200, Tomi Valkeinen wrote:
>> From: Sebastian Reichel <sebastian.reichel@collabora.com>
>>
>> In preparation for removing custom DSS calls from the DSI
>> panel driver, this moves support for external tearing event
>> GPIOs into the DSI host driver. This way tearing events are
>> always handled in the core resulting in simplification of
>> the panel drivers.
>>
>> The TE GPIO acquisition follows works in the same way as the
>> exynos DSI implementation.
>>
>> Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
>> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
>> ---
>> .../gpu/drm/omapdrm/displays/panel-dsi-cm.c | 101 +------------
>> drivers/gpu/drm/omapdrm/dss/dsi.c | 138 ++++++++++++++++--
>> 2 files changed, 133 insertions(+), 106 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/omapdrm/displays/panel-dsi-cm.c b/drivers/gpu/drm/omapdrm/displays/panel-dsi-cm.c
>> index 8890ee2ba830..43f63b5a120b 100644
>> --- a/drivers/gpu/drm/omapdrm/displays/panel-dsi-cm.c
>> +++ b/drivers/gpu/drm/omapdrm/displays/panel-dsi-cm.c
>> @@ -54,7 +54,6 @@ struct panel_drv_data {
>>
>> /* panel HW configuration from DT or platform data */
>> struct gpio_desc *reset_gpio;
>> - struct gpio_desc *ext_te_gpio;
>>
>> struct regulator_bulk_data supplies[DCS_REGULATOR_SUPPLY_NUM];
>>
>> @@ -68,10 +67,6 @@ struct panel_drv_data {
>>
>> bool te_enabled;
>>
>> - atomic_t do_update;
>> -
>> - struct delayed_work te_timeout_work;
>> -
>> bool intro_printed;
>>
>> struct workqueue_struct *workqueue;
>> @@ -83,8 +78,6 @@ struct panel_drv_data {
>>
>> #define to_panel_data(p) container_of(p, struct panel_drv_data, dssdev)
>>
>> -static irqreturn_t dsicm_te_isr(int irq, void *data);
>> -static void dsicm_te_timeout_work_callback(struct work_struct *work);
>> static int _dsicm_enable_te(struct panel_drv_data *ddata, bool enable);
>>
>> static int dsicm_panel_reset(struct panel_drv_data *ddata);
>> @@ -240,9 +233,6 @@ static int dsicm_enter_ulps(struct panel_drv_data *ddata)
>> if (r)
>> goto err;
>>
>> - if (ddata->ext_te_gpio)
>> - disable_irq(gpiod_to_irq(ddata->ext_te_gpio));
>> -
>> src->ops->dsi.disable(src, false, true);
>>
>> ddata->ulps_enabled = true;
>> @@ -271,15 +261,12 @@ static int dsicm_exit_ulps(struct panel_drv_data *ddata)
>> src->ops->enable(src);
>> ddata->dsi->mode_flags &= ~MIPI_DSI_MODE_LPM;
>>
>> - r = _dsicm_enable_te(ddata, true);
>> + r = _dsicm_enable_te(ddata, ddata->te_enabled);
>> if (r) {
>> dev_err(&ddata->dsi->dev, "failed to re-enable TE");
>> goto err2;
>> }
>>
>> - if (ddata->ext_te_gpio)
>> - enable_irq(gpiod_to_irq(ddata->ext_te_gpio));
>> -
>> dsicm_queue_ulps_work(ddata);
>>
>> ddata->ulps_enabled = false;
>> @@ -290,11 +277,8 @@ static int dsicm_exit_ulps(struct panel_drv_data *ddata)
>> dev_err(&ddata->dsi->dev, "failed to exit ULPS");
>>
>> r = dsicm_panel_reset(ddata);
>> - if (!r) {
>> - if (ddata->ext_te_gpio)
>> - enable_irq(gpiod_to_irq(ddata->ext_te_gpio));
>> + if (!r)
>> ddata->ulps_enabled = false;
>> - }
>>
>> dsicm_queue_ulps_work(ddata);
>>
>> @@ -745,43 +729,6 @@ static void dsicm_framedone_cb(int err, void *data)
>> src->ops->dsi.bus_unlock(src);
>> }
>>
>> -static irqreturn_t dsicm_te_isr(int irq, void *data)
>> -{
>> - struct panel_drv_data *ddata = data;
>> - struct omap_dss_device *src = ddata->src;
>> - int old;
>> - int r;
>> -
>> - old = atomic_cmpxchg(&ddata->do_update, 1, 0);
>> -
>> - if (old) {
>> - cancel_delayed_work(&ddata->te_timeout_work);
>> -
>> - r = src->ops->dsi.update(src, ddata->dsi->channel, dsicm_framedone_cb,
>> - ddata);
>> - if (r)
>> - goto err;
>> - }
>> -
>> - return IRQ_HANDLED;
>> -err:
>> - dev_err(&ddata->dsi->dev, "start update failed\n");
>> - src->ops->dsi.bus_unlock(src);
>> - return IRQ_HANDLED;
>> -}
>> -
>> -static void dsicm_te_timeout_work_callback(struct work_struct *work)
>> -{
>> - struct panel_drv_data *ddata = container_of(work, struct panel_drv_data,
>> - te_timeout_work.work);
>> - struct omap_dss_device *src = ddata->src;
>> -
>> - dev_err(&ddata->dsi->dev, "TE not received for 250ms!\n");
>> -
>> - atomic_set(&ddata->do_update, 0);
>> - src->ops->dsi.bus_unlock(src);
>> -}
>> -
>> static int dsicm_update(struct omap_dss_device *dssdev,
>> u16 x, u16 y, u16 w, u16 h)
>> {
>> @@ -809,16 +756,10 @@ static int dsicm_update(struct omap_dss_device *dssdev,
>> if (r)
>> goto err;
>>
>> - if (ddata->te_enabled && ddata->ext_te_gpio) {
>> - schedule_delayed_work(&ddata->te_timeout_work,
>> - msecs_to_jiffies(250));
>> - atomic_set(&ddata->do_update, 1);
>> - } else {
>> - r = src->ops->dsi.update(src, ddata->dsi->channel, dsicm_framedone_cb,
>> - ddata);
>> - if (r)
>> - goto err;
>> - }
>> + r = src->ops->dsi.update(src, ddata->dsi->channel, dsicm_framedone_cb,
>> + ddata);
>> + if (r)
>> + goto err;
>>
>> /* note: no bus_unlock here. unlock is src framedone_cb */
>> mutex_unlock(&ddata->lock);
>> @@ -840,8 +781,7 @@ static int _dsicm_enable_te(struct panel_drv_data *ddata, bool enable)
>> else
>> r = mipi_dsi_dcs_set_tear_off(dsi);
>>
>> - if (!ddata->ext_te_gpio)
>> - src->ops->dsi.enable_te(src, enable);
>> + src->ops->dsi.enable_te(src, enable);
>>
>> /* possible panel bug */
>> msleep(100);
>> @@ -934,14 +874,6 @@ static int dsicm_probe_of(struct mipi_dsi_device *dsi)
>> return err;
>> }
>>
>> - ddata->ext_te_gpio = devm_gpiod_get_optional(&dsi->dev, "te",
>> - GPIOD_IN);
>> - if (IS_ERR(ddata->ext_te_gpio)) {
>> - err = PTR_ERR(ddata->ext_te_gpio);
>> - dev_err(&dsi->dev, "TE gpio request failed: %d", err);
>> - return err;
>> - }
>> -
>> err = of_get_display_timing(node, "panel-timing", &timing);
>> if (!err) {
>> videomode_from_timing(&timing, &ddata->vm);
>> @@ -1024,25 +956,6 @@ static int dsicm_probe(struct mipi_dsi_device *dsi)
>>
>> mutex_init(&ddata->lock);
>>
>> - atomic_set(&ddata->do_update, 0);
>> -
>> - if (ddata->ext_te_gpio) {
>> - r = devm_request_irq(dev, gpiod_to_irq(ddata->ext_te_gpio),
>> - dsicm_te_isr,
>> - IRQF_TRIGGER_RISING,
>> - "taal vsync", ddata);
>> -
>> - if (r) {
>> - dev_err(dev, "IRQ request failed\n");
>> - goto err_reg;
>> - }
>> -
>> - INIT_DEFERRABLE_WORK(&ddata->te_timeout_work,
>> - dsicm_te_timeout_work_callback);
>> -
>> - dev_dbg(dev, "Using GPIO TE\n");
>> - }
>> -
>> ddata->workqueue = create_singlethread_workqueue("dsicm_wq");
>> if (!ddata->workqueue) {
>> r = -ENOMEM;
>> diff --git a/drivers/gpu/drm/omapdrm/dss/dsi.c b/drivers/gpu/drm/omapdrm/dss/dsi.c
>> index 003d26cead5a..921e7a1e1014 100644
>> --- a/drivers/gpu/drm/omapdrm/dss/dsi.c
>> +++ b/drivers/gpu/drm/omapdrm/dss/dsi.c
>> @@ -14,7 +14,9 @@
>> #include <linux/device.h>
>> #include <linux/err.h>
>> #include <linux/interrupt.h>
>> +#include <linux/irq.h>
>> #include <linux/delay.h>
>> +#include <linux/gpio/consumer.h>
>
> You could sort the headers while at it :-)

I'll do that after the series.

>> #include <linux/mutex.h>
>> #include <linux/module.h>
>> #include <linux/semaphore.h>
>> @@ -368,6 +370,11 @@ struct dsi_data {
>> unsigned int update_bytes;
>> #endif
>>
>> + /* external TE GPIO */
>> + struct gpio_desc *te_gpio;
>> + struct delayed_work te_timeout_work;
>> + atomic_t do_ext_te_update;
>> +
>> bool te_enabled;
>> bool ulps_enabled;
>>
>> @@ -3827,19 +3834,12 @@ static void dsi_framedone_irq_callback(void *data)
>> dsi_handle_framedone(dsi, 0);
>> }
>>
>> -static int dsi_update(struct omap_dss_device *dssdev, int channel,
>> - void (*callback)(int, void *), void *data)
>> +static int _dsi_update(struct dsi_data *dsi)
>> {
>> - struct dsi_data *dsi = to_dsi_data(dssdev);
>> u16 dw, dh;
>>
>> dsi_perf_mark_setup(dsi);
>>
>> - dsi->update_channel = channel;
>> -
>> - dsi->framedone_callback = callback;
>> - dsi->framedone_data = data;
>> -
>> dw = dsi->vm.hactive;
>> dh = dsi->vm.vactive;
>>
>> @@ -3852,6 +3852,26 @@ static int dsi_update(struct omap_dss_device *dssdev, int channel,
>> return 0;
>> }
>>
>> +static int dsi_update(struct omap_dss_device *dssdev, int channel,
>> + void (*callback)(int, void *), void *data)
>> +{
>> + struct dsi_data *dsi = to_dsi_data(dssdev);
>> +
>> + dsi->update_channel = channel;
>> + dsi->framedone_callback = callback;
>> + dsi->framedone_data = data;
>> +
>> + if (dsi->te_enabled && dsi->te_gpio) {
>> + schedule_delayed_work(&dsi->te_timeout_work,
>> + msecs_to_jiffies(250));
>> + atomic_set(&dsi->do_ext_te_update, 1);
>> + } else {
>> + _dsi_update(dsi);
>> + }
>> +
>> + return 0;
>> +}
>> +
>> /* Display funcs */
>>
>> static int dsi_configure_dispc_clocks(struct dsi_data *dsi)
>> @@ -4095,6 +4115,14 @@ static int dsi_enable_te(struct omap_dss_device *dssdev, bool enable)
>> struct dsi_data *dsi = to_dsi_data(dssdev);
>>
>> dsi->te_enabled = enable;
>> +
>> + if (dsi->te_gpio) {
>> + if (enable)
>> + enable_irq(gpiod_to_irq(dsi->te_gpio));
>> + else
>> + disable_irq(gpiod_to_irq(dsi->te_gpio));
>> + }
>> +
>> return 0;
>> }
>>
>> @@ -4772,11 +4800,89 @@ static const struct omap_dss_device_ops dsi_ops = {
>> },
>> };
>>
>> +static irqreturn_t omap_dsi_te_irq_handler(int irq, void *dev_id)
>> +{
>> + struct dsi_data *dsi = (struct dsi_data *)dev_id;
>> + int old;
>> +
>> + old = atomic_cmpxchg(&dsi->do_ext_te_update, 1, 0);
>> + if (old) {
>> + cancel_delayed_work(&dsi->te_timeout_work);
>> + _dsi_update(dsi);
>> + }
>> +
>> + return IRQ_HANDLED;
>> +}
>> +
>> +static void omap_dsi_te_timeout_work_callback(struct work_struct *work)
>> +{
>> + struct dsi_data *dsi = container_of(work, struct dsi_data,
>> + te_timeout_work.work);
>
> Strange indentation.
>
>> + int old;
>> +
>> + old = atomic_cmpxchg(&dsi->do_ext_te_update, 1, 0);
>> + if (old) {
>> + dev_err(dsi->dev, "TE not received for 250ms!\n");
>> + _dsi_update(dsi);
>> + }
>> +}
>> +
>> +static int omap_dsi_register_te_irq(struct dsi_data *dsi,
>> + struct mipi_dsi_device *client)
>> +{
>> + int err;
>> + int te_irq;
>> +
>> + dsi->te_gpio = gpiod_get_from_of_node(client->dev.of_node,
>
> Could we call gpiod_get(&client->dev, "te", ...) instead ?

Yep.

>> + "te-gpios", 0, GPIOD_IN,
>> + "dsi-tearing-effect");
>> + if (IS_ERR(dsi->te_gpio)) {
>> + err = PTR_ERR(dsi->te_gpio);
>> +
>> + if (err == -ENOENT) {
>> + dsi->te_gpio = NULL;
>> + return 0;
>> + }
>> +
>> + dev_err(dsi->dev, "Could not get TE gpio: %d\n", err);
>> + return err;
>> + }
>> +
>> + te_irq = gpiod_to_irq(dsi->te_gpio);
>
> Could this fail ?

Yes, I'll add error handling.

>> + irq_set_status_flags(te_irq, IRQ_NOAUTOEN);
>> +
>> + err = request_threaded_irq(te_irq, omap_dsi_te_irq_handler, NULL,
>> + IRQF_TRIGGER_RISING, "TE", dsi);
>
> What's the reason to request a threaded IRQ instead of a regular IRQ if
> the threaded handler is NULL ?

Probably just a mistake. I'll change this to use the threaded handler.

>> + if (err) {
>> + dev_err(dsi->dev, "request irq failed with %d\n", err);
>> + gpiod_put(dsi->te_gpio);
>> + return err;
>> + }
>> +
>> + INIT_DEFERRABLE_WORK(&dsi->te_timeout_work,
>> + omap_dsi_te_timeout_work_callback);
>> +
>> + dev_dbg(dsi->dev, "Using GPIO TE\n");
>> +
>> + return 0;
>> +}
>> +
>> +static void omap_dsi_unregister_te_irq(struct dsi_data *dsi)
>> +{
>> + if (dsi->te_gpio) {
>> + free_irq(gpiod_to_irq(dsi->te_gpio), dsi);
>
> You could store the IRQ number in dsi_data to avoid recomputing it.

Yep.

Tomi