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OMAPDSS: encoder-tpd12s015: Fix race issue with LS_OE 

A race issue has been observed with the encoder-tpd12s015 driver, which
leads to errors when trying to read EDID. This has only now been
observed, as OMAP4 and OMAP5 boards used SoC's GPIOs for LS_OE GPIO. On
dra7-evm boards, the LS_OE is behind a i2c controlled GPIO expander,
which increases the time to set the LS_OE.

This patch simplifies the handling of the LS_OE gpio in the driver by
removing the interrupt handling totally. The only time we actually need
to enable LS_OE is when we are reading the EDID, and thus we can just
set and clear the LS_OE gpio inside the read_edid() function.

This also has the additional benefit of very slightly decreasing the
power consumption.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
This commit is contained in:
Tomi Valkeinen 2014-09-19 16:58:57 +00:00
parent fa0c52ab23
commit a87a6d6b09
1 changed files with 10 additions and 47 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

57
drivers/video/fbdev/omap2/displays-new/encoder-tpd12s015.c
View File

@ -29,33 +29,10 @@ struct panel_drv_data {
int hpd_gpio;
struct omap_video_timings timings;
struct completion hpd_completion;
};
#define to_panel_data(x) container_of(x, struct panel_drv_data, dssdev)
static irqreturn_t tpd_hpd_irq_handler(int irq, void *data)
{
struct panel_drv_data *ddata = data;
bool hpd;
hpd = gpio_get_value_cansleep(ddata->hpd_gpio);
dev_dbg(ddata->dssdev.dev, "hpd %d\n", hpd);
if (gpio_is_valid(ddata->ls_oe_gpio)) {
if (hpd)
gpio_set_value_cansleep(ddata->ls_oe_gpio, 1);
else
gpio_set_value_cansleep(ddata->ls_oe_gpio, 0);
}
complete_all(&ddata->hpd_completion);
return IRQ_HANDLED;
}
static int tpd_connect(struct omap_dss_device *dssdev,
struct omap_dss_device *dst)
{
@ -70,23 +47,10 @@ static int tpd_connect(struct omap_dss_device *dssdev,
dst->src = dssdev;
dssdev->dst = dst;
reinit_completion(&ddata->hpd_completion);
gpio_set_value_cansleep(ddata->ct_cp_hpd_gpio, 1);
/* DC-DC converter needs at max 300us to get to 90% of 5V */
udelay(300);
/*
* If there's a cable connected, wait for the hpd irq to trigger,
* which turns on the level shifters.
*/
if (gpio_get_value_cansleep(ddata->hpd_gpio)) {
unsigned long to;
to = wait_for_completion_timeout(&ddata->hpd_completion,
msecs_to_jiffies(250));
WARN_ON_ONCE(to == 0);
}
return 0;
}
@ -179,11 +143,20 @@ static int tpd_read_edid(struct omap_dss_device *dssdev,
{
struct panel_drv_data *ddata = to_panel_data(dssdev);
struct omap_dss_device *in = ddata->in;
int r;
if (!gpio_get_value_cansleep(ddata->hpd_gpio))
return -ENODEV;
return in->ops.hdmi->read_edid(in, edid, len);
if (gpio_is_valid(ddata->ls_oe_gpio))
gpio_set_value_cansleep(ddata->ls_oe_gpio, 1);
r = in->ops.hdmi->read_edid(in, edid, len);
if (gpio_is_valid(ddata->ls_oe_gpio))
gpio_set_value_cansleep(ddata->ls_oe_gpio, 0);
return r;
}
static bool tpd_detect(struct omap_dss_device *dssdev)
@ -309,8 +282,6 @@ static int tpd_probe(struct platform_device *pdev)
platform_set_drvdata(pdev, ddata);
init_completion(&ddata->hpd_completion);
if (dev_get_platdata(&pdev->dev)) {
r = tpd_probe_pdata(pdev);
if (r)
@ -340,13 +311,6 @@ static int tpd_probe(struct platform_device *pdev)
if (r)
goto err_gpio;
r = devm_request_threaded_irq(&pdev->dev, gpio_to_irq(ddata->hpd_gpio),
NULL, tpd_hpd_irq_handler,
IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING |
IRQF_ONESHOT, "hpd", ddata);
if (r)
goto err_irq;
dssdev = &ddata->dssdev;
dssdev->ops.hdmi = &tpd_hdmi_ops;
dssdev->dev = &pdev->dev;
@ -365,7 +329,6 @@ static int tpd_probe(struct platform_device *pdev)
return 0;
err_reg:
err_irq:
err_gpio:
omap_dss_put_device(ddata->in);
return r;