[PATCH V2 8/9] drm/bridge: Add PS8622 bridge driver
Ajay kumar
ajaynumb at gmail.com
Tue Apr 22 06:57:17 PDT 2014
Hi Jingoo,
On Tue, Apr 22, 2014 at 2:13 PM, Jingoo Han <jg1.han at samsung.com> wrote:
> On Tuesday, April 22, 2014 7:39 AM, Ajay Kumar wrote:
> >
> > This patch adds a drm_bridge driver for the PS8622 DisplayPort to LVDS
> > bridge chip.
> >
> > Signed-off-by: Andrew Bresticker <abrestic at chromium.org>
> > Signed-off-by: Sean Paul <seanpaul at chromium.org>
> > Signed-off-by: Rahul Sharma <rahul.sharma at samsung.com>
> > Signed-off-by: Ajay Kumar <ajaykumar.rs at samsung.com>
> > ---
> > Changes since V1:
> > Pushing V1 for this as V2 because this patch holds good in this
> series.
> >
> > drivers/gpu/drm/bridge/Kconfig | 7 +
> > drivers/gpu/drm/bridge/Makefile | 1 +
> > drivers/gpu/drm/bridge/ps8622.c | 566
> +++++++++++++++++++++++++++++++++++++++
> > include/drm/bridge/ps8622.h | 42 +++
> > 4 files changed, 616 insertions(+)
> > create mode 100644 drivers/gpu/drm/bridge/ps8622.c
> > create mode 100644 include/drm/bridge/ps8622.h
> >
> > diff --git a/drivers/gpu/drm/bridge/Kconfig
> b/drivers/gpu/drm/bridge/Kconfig
> > index 3bc6845..aba21fc 100644
> > --- a/drivers/gpu/drm/bridge/Kconfig
> > +++ b/drivers/gpu/drm/bridge/Kconfig
> > @@ -4,3 +4,10 @@ config DRM_PTN3460
> > select DRM_KMS_HELPER
> > select DRM_PANEL
> > ---help---
> > +
> > +config DRM_PS8622
> > + tristate "Parade eDP/LVDS bridge"
> > + depends on DRM
> > + select DRM_KMS_HELPER
> > + select DRM_PANEL
>
> Please add the following select.
>
> + select BACKLIGHT_LCD_SUPPORT
> + select BACKLIGHT_CLASS_DEVICE
>
> Without this, the following build issues happen.
>
> drivers/gpu/drm/bridge/ps8622.c:353: undefined reference to
> `backlight_device_unregister'
> drivers/built-in.o: In function `ps8622_init':
> drivers/gpu/drm/bridge/ps8622.c:559: undefined reference to
> `backlight_device_unregister'
> drivers/gpu/drm/bridge/ps8622.c:507: undefined reference to
> `backlight_device_register'
>
> Right. I will add it.
> > + ---help---
> > diff --git a/drivers/gpu/drm/bridge/Makefile
> b/drivers/gpu/drm/bridge/Makefile
> > index b4733e1..d1b5daa 100644
> > --- a/drivers/gpu/drm/bridge/Makefile
> > +++ b/drivers/gpu/drm/bridge/Makefile
> > @@ -1,3 +1,4 @@
> > ccflags-y := -Iinclude/drm
> >
> > obj-$(CONFIG_DRM_PTN3460) += ptn3460.o
> > +obj-$(CONFIG_DRM_PS8622) += ps8622.o
> > diff --git a/drivers/gpu/drm/bridge/ps8622.c
> b/drivers/gpu/drm/bridge/ps8622.c
> > new file mode 100644
> > index 0000000..1e6b3ca
> > --- /dev/null
> > +++ b/drivers/gpu/drm/bridge/ps8622.c
>
> [.....]
>
> > +static int ps8622_send_config(struct ps8622_bridge *ps_bridge)
> > +{
> > + struct i2c_client *cl = ps_bridge->client;
> > + int err = 0;
> > +
> > + /* wait 20ms after power ON */
> > + usleep_range(20000, 30000);
> > +
> > + err |= ps8622_set(cl, 0x02, 0xa1, 0x01); /* HPD low */
> > + /* SW setting */
> > + err |= ps8622_set(cl, 0x04, 0x14, 0x01); /* [1:0] SW output 1.2V
> voltage
> > + * is lower to 96% */
>
> The comment style looks awkward.
> Please choose one of two options. And change all comments in this file.
>
> 1.
>
> + /* SW setting */
> + err |= ps8622_set(cl, 0x04, 0x14, 0x01); /* [1:0] SW output 1.2V
> voltage is lower to 96% */
>
> 2.
>
> + /* SW setting */
> + /* [1:0] SW output 1.2V voltage is lower to 96% */
> + err |= ps8622_set(cl, 0x04, 0x14, 0x01);
>
> Will use this.
> > + /* RCO SS setting */
> > + err |= ps8622_set(cl, 0x04, 0xe3, 0x20); /* [5:4] = b01 0.5%, b10
> 1%,
> > + * b11 1.5% */
> > + err |= ps8622_set(cl, 0x04, 0xe2, 0x80); /* [7] RCO SS enable */
> > + /* RPHY Setting */
> > + err |= ps8622_set(cl, 0x04, 0x8a, 0x0c); /* [3:2] CDR tune wait
> cycle
> > + * before measure for
> fine tune
> > + * b00: 1us b01: 0.5us
> b10:2us
> > + * b11: 4us */
> > + err |= ps8622_set(cl, 0x04, 0x89, 0x08); /* [3] RFD always on */
> > + err |= ps8622_set(cl, 0x04, 0x71, 0x2d); /* CTN lock in/out:
> > + * 20000ppm/80000ppm.
> > + * Lock out 2 times. */
> > + /* 2.7G CDR settings */
> > + err |= ps8622_set(cl, 0x04, 0x7d, 0x07); /* NOF=40LSB for HBR CDR
> > + * setting */
> > + err |= ps8622_set(cl, 0x04, 0x7b, 0x00); /* [1:0] Fmin=+4bands */
> > + err |= ps8622_set(cl, 0x04, 0x7a, 0xfd); /* [7:5] DCO_FTRNG=+-40%
> */
> > + /* 1.62G CDR settings */
> > + err |= ps8622_set(cl, 0x04, 0xc0, 0x12); /* [5:2]NOF=64LSB [1:0]DCO
> > + * scale is 2/5 */
> > + err |= ps8622_set(cl, 0x04, 0xc1, 0x92); /* Gitune=-37% */
> > + err |= ps8622_set(cl, 0x04, 0xc2, 0x1c); /* Fbstep=100% */
> > + err |= ps8622_set(cl, 0x04, 0x32, 0x80); /* [7] LOS signal disable
> */
> > + /* RPIO Setting */
> > + err |= ps8622_set(cl, 0x04, 0x00, 0xb0); /* [7:4] LVDS driver bias
> > + * current : 75% (250mV
> swing)
> > + * */
> > + err |= ps8622_set(cl, 0x04, 0x15, 0x40); /* [7:6] Right-bar GPIO
> output
> > + * strength is 8mA */
> > + /* EQ Training State Machine Setting */
> > + err |= ps8622_set(cl, 0x04, 0x54, 0x10); /* RCO calibration start
> */
> > + /* Logic, needs more than 10 I2C command */
> > + err |= ps8622_set(cl, 0x01, 0x02, 0x80 |
> ps_bridge->max_lane_count);
> > + /* [4:0] MAX_LANE_COUNT
> set to
> > + * max supported lanes */
> > + err |= ps8622_set(cl, 0x01, 0x21, 0x80 | ps_bridge->lane_count);
> > + /* [4:0] LANE_COUNT_SET
> set to
> > + * chosen lane count */
> > + err |= ps8622_set(cl, 0x00, 0x52, 0x20);
> > + err |= ps8622_set(cl, 0x00, 0xf1, 0x03); /* HPD CP toggle enable */
> > + err |= ps8622_set(cl, 0x00, 0x62, 0x41);
> > + err |= ps8622_set(cl, 0x00, 0xf6, 0x01); /* Counter number, add 1ms
> > + * counter delay */
> > + err |= ps8622_set(cl, 0x00, 0x77, 0x06); /* [6]PWM function
> control by
> > + * DPCD0040f[7], default
> is PWM
> > + * block always works. */
> > + err |= ps8622_set(cl, 0x00, 0x4c, 0x04); /* 04h Adjust VTotal
> tolerance
> > + * to fix the 30Hz no
> display
> > + * issue */
> > + err |= ps8622_set(cl, 0x01, 0xc0, 0x00); /* DPCD00400='h00, Parade
> OUI =
> > + * 'h001cf8 */
> > + err |= ps8622_set(cl, 0x01, 0xc1, 0x1c); /* DPCD00401='h1c */
> > + err |= ps8622_set(cl, 0x01, 0xc2, 0xf8); /* DPCD00402='hf8 */
> > + err |= ps8622_set(cl, 0x01, 0xc3, 0x44); /* DPCD403~408 = ASCII
> code
> > + * D2SLV5='h4432534c5635
> */
> > + err |= ps8622_set(cl, 0x01, 0xc4, 0x32); /* DPCD404 */
> > + err |= ps8622_set(cl, 0x01, 0xc5, 0x53); /* DPCD405 */
> > + err |= ps8622_set(cl, 0x01, 0xc6, 0x4c); /* DPCD406 */
> > + err |= ps8622_set(cl, 0x01, 0xc7, 0x56); /* DPCD407 */
> > + err |= ps8622_set(cl, 0x01, 0xc8, 0x35); /* DPCD408 */
> > + err |= ps8622_set(cl, 0x01, 0xca, 0x01); /* DPCD40A, Initial Code
> major
> > + * revision '01' */
> > + err |= ps8622_set(cl, 0x01, 0xcb, 0x05); /* DPCD40B, Initial Code
> minor
> > + * revision '05' */
> > + if (ps_bridge->bl) {
> > + err |= ps8622_set(cl, 0x01, 0xa5, 0xa0);
> > + /* DPCD720, internal PWM */
> > + err |= ps8622_set(cl, 0x01, 0xa7,
> > + ps_bridge->bl->props.brightness);
> > + /* FFh for 100%
> brightness,
> > + * 0h for 0% brightness
> */
> > + } else {
> > + err |= ps8622_set(cl, 0x01, 0xa5, 0x80);
> > + /* DPCD720, external PWM */
> > + }
> > + err |= ps8622_set(cl, 0x01, 0xcc, 0x13); /* Set LVDS output as
> 6bit-VESA
> > + * mapping, single LVDS
> channel
> > + * */
> > + err |= ps8622_set(cl, 0x02, 0xb1, 0x20); /* Enable SSC set by
> register
> > + * */
> > + err |= ps8622_set(cl, 0x04, 0x10, 0x16); /* Set SSC enabled and
> +/-1%
> > + * central spreading */
> > + /* Logic end */
> > + err |= ps8622_set(cl, 0x04, 0x59, 0x60); /* MPU Clock source: LC
> => RCO
> > + * */
> > + err |= ps8622_set(cl, 0x04, 0x54, 0x14); /* LC -> RCO */
> > + err |= ps8622_set(cl, 0x02, 0xa1, 0x91); /* HPD high */
> > +
> > + return err ? -EIO : 0;
> > +}
> > +
>
> [.....]
>
> > +
> > +static void ps8622_pre_enable(struct drm_bridge *bridge)
> > +{
> > + struct ps8622_bridge *ps_bridge = bridge->driver_private;
> > + int ret;
> > +
> > + mutex_lock(&ps_bridge->enable_mutex);
> > + if (ps_bridge->enabled)
> > + goto out;
> > +
> > + if (gpio_is_valid(ps_bridge->gpio_rst_n))
> > + gpio_set_value(ps_bridge->gpio_rst_n, 0);
> > +
> > + if (ps_bridge->v12) {
> > + ret = regulator_enable(ps_bridge->v12);
> > + if (ret)
> > + DRM_ERROR("fails to enable ps_bridge->v12");
> > + }
> > +
> > + drm_panel_pre_enable(ps_bridge->panel);
> > +
> > + if (gpio_is_valid(ps_bridge->gpio_slp_n))
> > + gpio_set_value(ps_bridge->gpio_slp_n, 1);
> > +
> > + /*
> > + * T1 is the range of time that it takes for the power to rise
> after we
> > + * enable the lcd fet. T2 is the range of time in which the data
> sheet
> > + * specifies we should deassert the reset pin.
> > + *
> > + * If it takes T1.max for the power to rise, we need to wait
> atleast
> > + * T2.min before deasserting the reset pin. If it takes T1.min for
> the
> > + * power to rise, we need to wait at most T2.max before
> deasserting the
> > + * reset pin.
> > + */
> > + usleep_range(PS8622_RST_HIGH_T2_MIN_US +
> PS8622_POWER_RISE_T1_MAX_US,
> > + PS8622_RST_HIGH_T2_MAX_US +
> PS8622_POWER_RISE_T1_MIN_US);
> > +
> > + if (gpio_is_valid(ps_bridge->gpio_rst_n))
> > + gpio_set_value(ps_bridge->gpio_rst_n, 1);
> > +
> > + ret = ps8622_send_config(ps_bridge);
> > + if (ret)
> > + DRM_ERROR("Failed to send config to bridge (%d)\n", ret);
> > +
> > + ps_bridge->enabled = true;
> > +
> > + mutex_unlock(&ps_bridge->enable_mutex);
> > + return;
> > +
> > +out:
> > +
> > + mutex_unlock(&ps_bridge->enable_mutex);
> > +}
>
> mutex_unlock() is duplicated. Also, 'return' is unnecessary.
> Please fix it as below.
>
> + ps_bridge->enabled = true;
> +
> +out:
> + mutex_unlock(&ps_bridge->enable_mutex);
> +}
>
Right. Will change it.
>
> > +
> > +static void ps8622_enable(struct drm_bridge *bridge)
> > +{
> > + struct ps8622_bridge *ps_bridge = bridge->driver_private;
> > +
> > + mutex_lock(&ps_bridge->enable_mutex);
> > + if (ps_bridge->enabled)
> > + drm_panel_enable(ps_bridge->panel);
> > + mutex_unlock(&ps_bridge->enable_mutex);
> > +}
> > +
> > +static void ps8622_disable(struct drm_bridge *bridge)
> > +{
> > + struct ps8622_bridge *ps_bridge = bridge->driver_private;
> > +
> > + mutex_lock(&ps_bridge->enable_mutex);
> > +
> > + if (!ps_bridge->enabled)
> > + goto out;
> > +
> > + ps_bridge->enabled = false;
> > +
> > + drm_panel_disable(ps_bridge->panel);
> > + msleep(PS8622_PWMO_END_T12_MS);
> > +
> > + /*
> > + * This doesn't matter if the regulators are turned off, but
> something
> > + * else might keep them on. In that case, we want to assert the
> slp gpio
> > + * to lower power.
> > + */
> > + if (gpio_is_valid(ps_bridge->gpio_slp_n))
> > + gpio_set_value(ps_bridge->gpio_slp_n, 0);
> > +
> > + drm_panel_post_disable(ps_bridge->panel);
> > + if (ps_bridge->v12)
> > + regulator_disable(ps_bridge->v12);
> > +
> > + /*
> > + * Sleep for at least the amount of time that it takes the power
> rail to
> > + * fall to prevent asserting the rst gpio from doing anything.
> > + */
> > + usleep_range(PS8622_POWER_FALL_T16_MAX_US,
> > + 2 * PS8622_POWER_FALL_T16_MAX_US);
> > + if (gpio_is_valid(ps_bridge->gpio_rst_n))
> > + gpio_set_value(ps_bridge->gpio_rst_n, 0);
> > +
> > + msleep(PS8622_POWER_OFF_T17_MS);
> > +
> > +out:
> > + mutex_unlock(&ps_bridge->enable_mutex);
> > +}
> > +
> > +static void ps8622_post_disable(struct drm_bridge *bridge)
> > +{
> > +}
>
> How about just removing this empty function?
That is not possible. Because the bridge callbacks are called in this
fashion:
bridge->funcs->post_disable(bridge);
So, if that particular callback turns NULL, it will crash!
>
[.....]
>
> Best regards,
> Jingoo Han
>
>
Regards,
Ajay Kumar
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