Hi Andrzej, On 05/14/2018 12:33 PM, Andrzej Hajda wrote: > On 14.05.2018 11:38, Philippe CORNU wrote: >> Hi Laurent, Archit, Andrzej & Yannick, >> >> Do you have any comments on this v2 driver part? >> (more details regarding v1/v2 differences in the cover letter >> https://www.spinics.net/lists/dri-devel/msg174137.html) >> >> Thank you, >> Philippe :-) >> >> >> On 04/25/2018 09:53 AM, Philippe Cornu wrote: >>> Add the optional power supplies using the description found in >>> "SiI9022A/SiI9024A HDMI Transmitter Data Sheet (August 2016)". >>> >>> The sii902x input IOs are not "io safe" so it is important to >>> enable/disable voltage regulators during probe/remove phases to >>> avoid damages. > > What exactly does it mean? Ie I understand that the chip has some > limitations, but why enabling/disabling regulators in probe/remove > should solve it?
thank you for your comment. And sorry for the "bad" explanation in the 2nd paragraph about the fact that inputs are not "io safe". I added this 2nd paragraph in v2 following a good comment from Laurent on adding the management of the regulators outside the probe/remove for a better power consumption management (enable/disable regulators only when the ic is used for displaying something for instance...). But after a deeper analysis, I realized that the only way to improve the power consumption is to implement & test the sii902x various sleep modes, that is out-of-scope of this small patch and also out-of-scope of my test board I use on which the sii902x bridge ic power consumption is very low compare to the rest of the system... I will remove this "explanation" in v3 as it creates confusion. Many thanks, Philippe :-) > > Regards > Andrzej > >>> >>> Signed-off-by: Philippe Cornu <[email protected]> >>> --- >>> drivers/gpu/drm/bridge/sii902x.c | 38 >>> ++++++++++++++++++++++++++++++++++---- >>> 1 file changed, 34 insertions(+), 4 deletions(-) >>> >>> diff --git a/drivers/gpu/drm/bridge/sii902x.c >>> b/drivers/gpu/drm/bridge/sii902x.c >>> index 60373d7eb220..c367d7b91ade 100644 >>> --- a/drivers/gpu/drm/bridge/sii902x.c >>> +++ b/drivers/gpu/drm/bridge/sii902x.c >>> @@ -24,6 +24,7 @@ >>> #include <linux/i2c.h> >>> #include <linux/module.h> >>> #include <linux/regmap.h> >>> +#include <linux/regulator/consumer.h> >>> >>> #include <drm/drmP.h> >>> #include <drm/drm_atomic_helper.h> >>> @@ -86,6 +87,7 @@ struct sii902x { >>> struct drm_bridge bridge; >>> struct drm_connector connector; >>> struct gpio_desc *reset_gpio; >>> + struct regulator_bulk_data supplies[2]; >>> }; >>> >>> static inline struct sii902x *bridge_to_sii902x(struct drm_bridge >>> *bridge) >>> @@ -392,23 +394,42 @@ static int sii902x_probe(struct i2c_client *client, >>> return PTR_ERR(sii902x->reset_gpio); >>> } >>> >>> + sii902x->supplies[0].supply = "iovcc"; >>> + sii902x->supplies[1].supply = "vcc12"; >>> + ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(sii902x->supplies), >>> + sii902x->supplies); >>> + if (ret) { >>> + dev_err(dev, "Failed to get power supplies: %d\n", ret); >>> + return ret; >>> + } >>> + >>> + ret = regulator_bulk_enable(ARRAY_SIZE(sii902x->supplies), >>> + sii902x->supplies); >>> + if (ret) { >>> + dev_err(dev, "Failed to enable power supplies: %d\n", ret); >>> + return ret; >>> + } >>> + >>> + usleep_range(10000, 20000); >>> + >>> sii902x_reset(sii902x); >>> >>> ret = regmap_write(sii902x->regmap, SII902X_REG_TPI_RQB, 0x0); >>> if (ret) >>> - return ret; >>> + goto err_disable_regulator; >>> >>> ret = regmap_bulk_read(sii902x->regmap, SII902X_REG_CHIPID(0), >>> &chipid, 4); >>> if (ret) { >>> dev_err(dev, "regmap_read failed %d\n", ret); >>> - return ret; >>> + goto err_disable_regulator; >>> } >>> >>> if (chipid[0] != 0xb0) { >>> dev_err(dev, "Invalid chipid: %02x (expecting 0xb0)\n", >>> chipid[0]); >>> - return -EINVAL; >>> + ret = -EINVAL; >>> + goto err_disable_regulator; >>> } >>> >>> /* Clear all pending interrupts */ >>> @@ -424,7 +445,7 @@ static int sii902x_probe(struct i2c_client *client, >>> IRQF_ONESHOT, dev_name(dev), >>> sii902x); >>> if (ret) >>> - return ret; >>> + goto err_disable_regulator; >>> } >>> >>> sii902x->bridge.funcs = &sii902x_bridge_funcs; >>> @@ -434,6 +455,12 @@ static int sii902x_probe(struct i2c_client *client, >>> i2c_set_clientdata(client, sii902x); >>> >>> return 0; >>> + >>> +err_disable_regulator: >>> + regulator_bulk_disable(ARRAY_SIZE(sii902x->supplies), >>> + sii902x->supplies); >>> + >>> + return ret; >>> } >>> >>> static int sii902x_remove(struct i2c_client *client) >>> @@ -443,6 +470,9 @@ static int sii902x_remove(struct i2c_client *client) >>> >>> drm_bridge_remove(&sii902x->bridge); >>> >>> + regulator_bulk_disable(ARRAY_SIZE(sii902x->supplies), >>> + sii902x->supplies); >>> + >>> return 0; >>> } >>> > > _______________________________________________ dri-devel mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/dri-devel
