OMAP: DSS2: DSI: add option to leave DSI lanes powered on

The DSI pins are powered by VDDS_DSI. If VDDS_DSI is off, the DSI pins
are floating even if they are pinmuxed to, say, safe mode and there's a
pull down/up.

This patch gives the panel drivers an option to leave the VDDS_DSI power
enabled while the DSS itself is turned off. This can be used to keep the
DSI lanes in a valid state while DSS is off, if the DSI pins are muxed
for pull down (not done in this patch).

There will be a slight power consumption increase (~100 uA?) when the
VDDS_DSI is left on, but because this option is used when the panel is
left on, the regulator consumption is negligible compared to panel power
consumption.

When the panel is fully turned off the VDDS_DSI is also turned off.

As an added bonus this will give us faster start up time when starting
up the DSS and the regulator is already enabled.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

diff --git a/drivers/video/omap2/displays/panel-taal.c b/drivers/video/omap2/displays/panel-taal.c
index 83b0316e35ad187bb5dd18f3faf49277c6e67c25..04d9bc94c5b317974d4ea067e57ce2176e6083ee 100644 (file)
--- a/drivers/video/omap2/displays/panel-taal.c
+++ b/drivers/video/omap2/displays/panel-taal.c
@@ -932,7 +932,7 @@ err:
 
        taal_hw_reset(dssdev);
 
-       omapdss_dsi_display_disable(dssdev);
+       omapdss_dsi_display_disable(dssdev, true);
 err0:
        return r;
 }
@@ -955,7 +955,7 @@ static void taal_power_off(struct omap_dss_device *dssdev)
                taal_hw_reset(dssdev);
        }
 
-       omapdss_dsi_display_disable(dssdev);
+       omapdss_dsi_display_disable(dssdev, true);
 
        td->enabled = 0;
 }

diff --git a/drivers/video/omap2/dss/dpi.c b/drivers/video/omap2/dss/dpi.c
index 4a2a1e1b195fd20fceba6472075506d13b238bb6..bec8c8a3b49dba6871c15630d6233fa1d051bbdc 100644 (file)
--- a/drivers/video/omap2/dss/dpi.c
+++ b/drivers/video/omap2/dss/dpi.c
@@ -206,7 +206,7 @@ int omapdss_dpi_display_enable(struct omap_dss_device *dssdev)
 
 err4:
        if (dpi_use_dsi_pll(dssdev))
-               dsi_pll_uninit();
+               dsi_pll_uninit(true);
 err3:
        if (dpi_use_dsi_pll(dssdev))
                dss_clk_disable(DSS_CLK_SYSCK);
@@ -227,7 +227,7 @@ void omapdss_dpi_display_disable(struct omap_dss_device *dssdev)
 
        if (dpi_use_dsi_pll(dssdev)) {
                dss_select_dispc_clk_source(OMAP_DSS_CLK_SRC_FCK);
-               dsi_pll_uninit();
+               dsi_pll_uninit(true);
                dss_clk_disable(DSS_CLK_SYSCK);
        }
 

diff --git a/drivers/video/omap2/dss/dsi.c b/drivers/video/omap2/dss/dsi.c
index e2ae1e7372f2ee926cefeda14b1b0ca47a6c2847..9befbceba10cd7e0a5340a8b237de8b0a6b75ab6 100644 (file)
--- a/drivers/video/omap2/dss/dsi.c
+++ b/drivers/video/omap2/dss/dsi.c
@@ -246,6 +246,7 @@ static struct
 
        struct dsi_clock_info current_cinfo;
 
+       bool vdds_dsi_enabled;
        struct regulator *vdds_dsi_reg;
 
        struct {
@@ -1445,9 +1446,12 @@ int dsi_pll_init(struct omap_dss_device *dssdev, bool enable_hsclk,
        enable_clocks(1);
        dsi_enable_pll_clock(1);
 
-       r = regulator_enable(dsi.vdds_dsi_reg);
-       if (r)
-               goto err0;
+       if (!dsi.vdds_dsi_enabled) {
+               r = regulator_enable(dsi.vdds_dsi_reg);
+               if (r)
+                       goto err0;
+               dsi.vdds_dsi_enabled = true;
+       }
 
        /* XXX PLL does not come out of reset without this... */
        dispc_pck_free_enable(1);
@@ -1481,21 +1485,28 @@ int dsi_pll_init(struct omap_dss_device *dssdev, bool enable_hsclk,
 
        return 0;
 err1:
-       regulator_disable(dsi.vdds_dsi_reg);
+       if (dsi.vdds_dsi_enabled) {
+               regulator_disable(dsi.vdds_dsi_reg);
+               dsi.vdds_dsi_enabled = false;
+       }
 err0:
        enable_clocks(0);
        dsi_enable_pll_clock(0);
        return r;
 }
 
-void dsi_pll_uninit(void)
+void dsi_pll_uninit(bool disconnect_lanes)
 {
        enable_clocks(0);
        dsi_enable_pll_clock(0);
 
        dsi.pll_locked = 0;
        dsi_pll_power(DSI_PLL_POWER_OFF);
-       regulator_disable(dsi.vdds_dsi_reg);
+       if (disconnect_lanes) {
+               WARN_ON(!dsi.vdds_dsi_enabled);
+               regulator_disable(dsi.vdds_dsi_reg);
+               dsi.vdds_dsi_enabled = false;
+       }
        DSSDBG("PLL uninit done\n");
 }
 
@@ -3642,12 +3653,13 @@ err2:
        dss_select_dispc_clk_source(OMAP_DSS_CLK_SRC_FCK);
        dss_select_dsi_clk_source(OMAP_DSS_CLK_SRC_FCK);
 err1:
-       dsi_pll_uninit();
+       dsi_pll_uninit(true);
 err0:
        return r;
 }
 
-static void dsi_display_uninit_dsi(struct omap_dss_device *dssdev)
+static void dsi_display_uninit_dsi(struct omap_dss_device *dssdev,
+               bool disconnect_lanes)
 {
        if (!dsi.ulps_enabled)
                dsi_enter_ulps();
@@ -3662,7 +3674,7 @@ static void dsi_display_uninit_dsi(struct omap_dss_device *dssdev)
        dss_select_dispc_clk_source(OMAP_DSS_CLK_SRC_FCK);
        dss_select_dsi_clk_source(OMAP_DSS_CLK_SRC_FCK);
        dsi_complexio_uninit();
-       dsi_pll_uninit();
+       dsi_pll_uninit(disconnect_lanes);
 }
 
 static int dsi_core_init(void)
@@ -3731,7 +3743,8 @@ err0:
 }
 EXPORT_SYMBOL(omapdss_dsi_display_enable);
 
-void omapdss_dsi_display_disable(struct omap_dss_device *dssdev)
+void omapdss_dsi_display_disable(struct omap_dss_device *dssdev,
+               bool disconnect_lanes)
 {
        DSSDBG("dsi_display_disable\n");
 
@@ -3741,7 +3754,7 @@ void omapdss_dsi_display_disable(struct omap_dss_device *dssdev)
 
        dsi_display_uninit_dispc(dssdev);
 
-       dsi_display_uninit_dsi(dssdev);
+       dsi_display_uninit_dsi(dssdev, disconnect_lanes);
 
        enable_clocks(0);
        dsi_enable_pll_clock(0);

diff --git a/drivers/video/omap2/dss/dss.h b/drivers/video/omap2/dss/dss.h
index d3b5697134e1aecc6d68f39e2a811072e076066c..eea5c7d58dde21d1c814a22acf5977551383ba2a 100644 (file)
--- a/drivers/video/omap2/dss/dss.h
+++ b/drivers/video/omap2/dss/dss.h
@@ -294,7 +294,7 @@ int dsi_pll_calc_clock_div_pck(bool is_tft, unsigned long req_pck,
                struct dispc_clock_info *dispc_cinfo);
 int dsi_pll_init(struct omap_dss_device *dssdev, bool enable_hsclk,
                bool enable_hsdiv);
-void dsi_pll_uninit(void);
+void dsi_pll_uninit(bool disconnect_lanes);
 void dsi_get_overlay_fifo_thresholds(enum omap_plane plane,
                u32 fifo_size, enum omap_burst_size *burst_size,
                u32 *fifo_low, u32 *fifo_high);

diff --git a/include/video/omapdss.h b/include/video/omapdss.h
index 8138613c3112323c810d6204cbb54830f5d5f348..0a10a234a989be555e32d597636a21b2433d38ba 100644 (file)
--- a/include/video/omapdss.h
+++ b/include/video/omapdss.h
@@ -589,7 +589,8 @@ int omap_dsi_set_vc_id(struct omap_dss_device *dssdev, int channel, int vc_id);
 void omap_dsi_release_vc(struct omap_dss_device *dssdev, int channel);
 
 int omapdss_dsi_display_enable(struct omap_dss_device *dssdev);
-void omapdss_dsi_display_disable(struct omap_dss_device *dssdev);
+void omapdss_dsi_display_disable(struct omap_dss_device *dssdev,
+               bool disconnect_lanes);
 
 int omapdss_dpi_display_enable(struct omap_dss_device *dssdev);
 void omapdss_dpi_display_disable(struct omap_dss_device *dssdev);