diff options
| -rw-r--r-- | arch/arm/boot/dts/omap3-minnow.dtsi | 16 | ||||
| -rw-r--r-- | drivers/video/omap2/displays/panel-minnow.c | 69 |
2 files changed, 82 insertions, 3 deletions
diff --git a/arch/arm/boot/dts/omap3-minnow.dtsi b/arch/arm/boot/dts/omap3-minnow.dtsi index 260d34d0f85..8ab4c721d1d 100644 --- a/arch/arm/boot/dts/omap3-minnow.dtsi +++ b/arch/arm/boot/dts/omap3-minnow.dtsi @@ -93,6 +93,9 @@ //pixel_format = <1>; //hs_clk = <90000000 150000000>; /* min max*/ //lp_clk = <7000000 9000000>; /* min max*/ + pinctrl-names = "viopulldown", "viooutput"; + pinctrl-0 = <&display_vddio_pulldown>; + pinctrl-1 = <&display_vddio_output>; }; c55-ctrl@0 { @@ -585,7 +588,6 @@ tps65912_0: tps65912 { 0x04e 0x00f /* GPMC_A3, GPIO 36, MODE7 | PD */ 0x056 0x00f /* GPMC_A7, GPIO 40, MODE7 | PD */ 0x058 0x00f /* GPMC_A8, GPIO 41, MODE7 | PD */ - 0x05a 0x004 /* GPMC_A9, MODE4 | OUTPUT */ 0x06e 0x00f /* GPMC_D8, GPIO 44, MODE7 | PD */ 0x070 0x00f /* GPMC_D9, GPIO 45, MODE7 | PD */ 0x072 0x00f /* GPMC_D10, GPIO 46, MODE7 | PD */ @@ -779,6 +781,18 @@ tps65912_0: tps65912 { 0x0e6 0x10c /* CAM_D0, MODE4 | INPUT_PULLDOWN */ >; }; + + display_vddio_pulldown: pinmux_vddio_pulldown { + pinctrl-single,pins = < + 0x05a 0x00f /* GPMC_A9, GPIO 42, MODE7 | PULLDOWN */ + >; + }; + + display_vddio_output: pinmux_vddio_output { + pinctrl-single,pins = < + 0x05a 0x004 /* GPMC_A9, GPIO 42, MODE4 | OUTPUT */ + >; + }; }; &omap3_pmx_wkup{ diff --git a/drivers/video/omap2/displays/panel-minnow.c b/drivers/video/omap2/displays/panel-minnow.c index 475bb8caf91..8d127ae401f 100644 --- a/drivers/video/omap2/displays/panel-minnow.c +++ b/drivers/video/omap2/displays/panel-minnow.c @@ -279,6 +279,9 @@ struct minnow_panel_data { int reset_gpio[MINNOW_COMPONENT_MAX]; int ext_te_gpio; int vio_en_gpio; + struct pinctrl *vio_pctrl; + struct pinctrl_state *vio_state_output; + struct pinctrl_state *vio_state_pulldown; int mem_en_gpio; struct minnow_panel_hw_reset hw_reset[MINNOW_COMPONENT_MAX]; struct regulator *regulators[MINNOW_COMPONENT_MAX]; @@ -2142,8 +2145,26 @@ static int minnow_panel_set_regulators(struct minnow_panel_data *mpd, static void minnow_panel_enable_vio(struct minnow_panel_data *mpd, bool enable) { if (enable) { - if (gpio_is_valid(mpd->vio_en_gpio)) + if (gpio_is_valid(mpd->vio_en_gpio)) { + /* This is workaround to fix unexpected M4 reset issue + * select pulldown mode to enable switch will tuen on + * 1.8v power supply slowly, that will help reduce the + * dip of 1.8v supply + */ + int r = pinctrl_select_state(mpd->vio_pctrl, + mpd->vio_state_pulldown); + if (r) + dev_err(&mpd->dssdev->dev, "failed to activate" + " vio_state_pulldown!"); + usleep_range(250, 300); + /* go back to output low mode to keep switch enabled */ gpio_set_value(mpd->vio_en_gpio, 0); + r = pinctrl_select_state(mpd->vio_pctrl, + mpd->vio_state_output); + if (r) + dev_err(&mpd->dssdev->dev, "failed to activate" + " vio_state_output!"); + } if (gpio_is_valid(mpd->mem_en_gpio)) gpio_set_value(mpd->mem_en_gpio, 1); } else { @@ -2252,6 +2273,25 @@ static int minnow_panel_dt_init(struct minnow_panel_data *mpd) DTINFO("gpio_te = %d\n", mpd->ext_te_gpio); mpd->vio_en_gpio = of_get_named_gpio(dt_node, "gpio_vio_en", 0); DTINFO("gpio_vio_en = %d\n", mpd->vio_en_gpio); + if (gpio_is_valid(mpd->vio_en_gpio)) { + mpd->vio_pctrl = devm_pinctrl_get(&mpd->dssdev->dev); + if (IS_ERR(mpd->vio_pctrl)) { + dev_err(&mpd->dssdev->dev, "no vio pinctrl handle\n"); + return PTR_ERR(mpd->vio_pctrl); + } + mpd->vio_state_pulldown = + pinctrl_lookup_state(mpd->vio_pctrl, "viopulldown"); + if (IS_ERR(mpd->vio_state_pulldown)) { + dev_err(&mpd->dssdev->dev, "no vio pulldown state\n"); + return PTR_ERR(mpd->vio_state_pulldown); + } + mpd->vio_state_output = + pinctrl_lookup_state(mpd->vio_pctrl, "viooutput"); + if (IS_ERR(mpd->vio_state_output)) { + dev_err(&mpd->dssdev->dev, "no vio output state\n"); + return PTR_ERR(mpd->vio_state_output); + } + } mpd->mem_en_gpio = of_get_named_gpio(dt_node, "gpio_mem_en", 0); DTINFO("gpio_mem_en = %d\n", mpd->mem_en_gpio); mpd->vsync_events_gpio = of_get_named_gpio(dt_node, @@ -2476,6 +2516,13 @@ static int minnow_panel_probe(struct omap_dss_device *dssdev) "failed to request panel vio_en gpio\n"); return r; } + r = pinctrl_select_state(mpd->vio_pctrl, + mpd->vio_state_output); + if (r) { + dev_err(&mpd->dssdev->dev, + "failed to activate vio output state!"); + return r; + } } if (gpio_is_valid(mpd->mem_en_gpio)) { @@ -2902,10 +2949,28 @@ static int minnow_panel_enable_locked(struct minnow_panel_data *mpd) r = minnow_panel_set_regulators(mpd, regulator_enable); if (r) goto err; - minnow_panel_enable_vio(mpd, true); + /* By default, there's a leakage current coming from peripheral + * 26 MHz clock, so turn on 1.8v VIO first, then turn on clk_in + * will help avoid the step issue of enable 1.8v VIO. + * But unfortunately, there is a big problem of the hardware now, + * when turn off VIO for long time(above 12 minutes), it occurred + * the capacitance fully discharged, when enable VIO later, it will + * pull down 1.8V power supply momently as the capacitance charging, + * that occurred M4 reset since power supply dip. + * So turn on peripheral 26 MHz clock first and waiting for 6ms, + * let leakage current fully charge the capacitance, then turn on + * VIO, that will help avoid unexpected M4 reset (it still has dip + * on 1.8V power supply but smaller than worse case) + * For the step issue of 1.8v VIO, it's not a big deal as the reset + * pin has been hold and will release after it reaches 1.8v for 20ms, + * this matches the requirement of Solomon power on sequence. + * This is just software work around to fix the hardware issue + */ r = minnow_panel_enable_clkin(mpd, true); if (r) goto err; + usleep_range(6000, 6300); + minnow_panel_enable_vio(mpd, true); r = minnow_panel_power_on(mpd); if (r) |