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path: root/drivers/gpu/host1x
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Diffstat (limited to 'drivers/gpu/host1x')
-rw-r--r--drivers/gpu/host1x/mipi.c110
1 files changed, 98 insertions, 12 deletions
diff --git a/drivers/gpu/host1x/mipi.c b/drivers/gpu/host1x/mipi.c
index 0989b8151b4c..52a6fd224127 100644
--- a/drivers/gpu/host1x/mipi.c
+++ b/drivers/gpu/host1x/mipi.c
@@ -118,9 +118,12 @@ struct tegra_mipi_soc {
struct tegra_mipi {
const struct tegra_mipi_soc *soc;
+ struct device *dev;
void __iomem *regs;
struct mutex lock;
struct clk *clk;
+
+ unsigned long usage_count;
};
struct tegra_mipi_device {
@@ -142,6 +145,67 @@ static inline void tegra_mipi_writel(struct tegra_mipi *mipi, u32 value,
writel(value, mipi->regs + (offset << 2));
}
+static int tegra_mipi_power_up(struct tegra_mipi *mipi)
+{
+ u32 value;
+ int err;
+
+ err = clk_enable(mipi->clk);
+ if (err < 0)
+ return err;
+
+ value = tegra_mipi_readl(mipi, MIPI_CAL_BIAS_PAD_CFG0);
+ value &= ~MIPI_CAL_BIAS_PAD_PDVCLAMP;
+
+ if (mipi->soc->needs_vclamp_ref)
+ value |= MIPI_CAL_BIAS_PAD_E_VCLAMP_REF;
+
+ tegra_mipi_writel(mipi, value, MIPI_CAL_BIAS_PAD_CFG0);
+
+ value = tegra_mipi_readl(mipi, MIPI_CAL_BIAS_PAD_CFG2);
+ value &= ~MIPI_CAL_BIAS_PAD_PDVREG;
+ tegra_mipi_writel(mipi, value, MIPI_CAL_BIAS_PAD_CFG2);
+
+ clk_disable(mipi->clk);
+
+ return 0;
+}
+
+static int tegra_mipi_power_down(struct tegra_mipi *mipi)
+{
+ u32 value;
+ int err;
+
+ err = clk_enable(mipi->clk);
+ if (err < 0)
+ return err;
+
+ /*
+ * The MIPI_CAL_BIAS_PAD_PDVREG controls a voltage regulator that
+ * supplies the DSI pads. This must be kept enabled until none of the
+ * DSI lanes are used anymore.
+ */
+ value = tegra_mipi_readl(mipi, MIPI_CAL_BIAS_PAD_CFG2);
+ value |= MIPI_CAL_BIAS_PAD_PDVREG;
+ tegra_mipi_writel(mipi, value, MIPI_CAL_BIAS_PAD_CFG2);
+
+ /*
+ * MIPI_CAL_BIAS_PAD_PDVCLAMP and MIPI_CAL_BIAS_PAD_E_VCLAMP_REF
+ * control a regulator that supplies current to the pre-driver logic.
+ * Powering down this regulator causes DSI to fail, so it must remain
+ * powered on until none of the DSI lanes are used anymore.
+ */
+ value = tegra_mipi_readl(mipi, MIPI_CAL_BIAS_PAD_CFG0);
+
+ if (mipi->soc->needs_vclamp_ref)
+ value &= ~MIPI_CAL_BIAS_PAD_E_VCLAMP_REF;
+
+ value |= MIPI_CAL_BIAS_PAD_PDVCLAMP;
+ tegra_mipi_writel(mipi, value, MIPI_CAL_BIAS_PAD_CFG0);
+
+ return 0;
+}
+
struct tegra_mipi_device *tegra_mipi_request(struct device *device)
{
struct device_node *np = device->of_node;
@@ -178,6 +242,20 @@ struct tegra_mipi_device *tegra_mipi_request(struct device *device)
dev->pads = args.args[0];
dev->device = device;
+ mutex_lock(&dev->mipi->lock);
+
+ if (dev->mipi->usage_count++ == 0) {
+ err = tegra_mipi_power_up(dev->mipi);
+ if (err < 0) {
+ dev_err(dev->mipi->dev,
+ "failed to power up MIPI bricks: %d\n",
+ err);
+ return ERR_PTR(err);
+ }
+ }
+
+ mutex_unlock(&dev->mipi->lock);
+
return dev;
put:
@@ -192,6 +270,25 @@ EXPORT_SYMBOL(tegra_mipi_request);
void tegra_mipi_free(struct tegra_mipi_device *device)
{
+ int err;
+
+ mutex_lock(&device->mipi->lock);
+
+ if (--device->mipi->usage_count == 0) {
+ err = tegra_mipi_power_down(device->mipi);
+ if (err < 0) {
+ /*
+ * Not much that can be done here, so an error message
+ * will have to do.
+ */
+ dev_err(device->mipi->dev,
+ "failed to power down MIPI bricks: %d\n",
+ err);
+ }
+ }
+
+ mutex_unlock(&device->mipi->lock);
+
platform_device_put(device->pdev);
kfree(device);
}
@@ -227,23 +324,11 @@ int tegra_mipi_calibrate(struct tegra_mipi_device *device)
mutex_lock(&device->mipi->lock);
- value = tegra_mipi_readl(device->mipi, MIPI_CAL_BIAS_PAD_CFG0);
- value &= ~MIPI_CAL_BIAS_PAD_PDVCLAMP;
-
- if (soc->needs_vclamp_ref)
- value |= MIPI_CAL_BIAS_PAD_E_VCLAMP_REF;
-
- tegra_mipi_writel(device->mipi, value, MIPI_CAL_BIAS_PAD_CFG0);
-
value = MIPI_CAL_BIAS_PAD_DRV_DN_REF(soc->pad_drive_down_ref) |
MIPI_CAL_BIAS_PAD_DRV_UP_REF(soc->pad_drive_up_ref);
tegra_mipi_writel(device->mipi, value, MIPI_CAL_BIAS_PAD_CFG1);
value = tegra_mipi_readl(device->mipi, MIPI_CAL_BIAS_PAD_CFG2);
- value &= ~MIPI_CAL_BIAS_PAD_PDVREG;
- tegra_mipi_writel(device->mipi, value, MIPI_CAL_BIAS_PAD_CFG2);
-
- value = tegra_mipi_readl(device->mipi, MIPI_CAL_BIAS_PAD_CFG2);
value &= ~MIPI_CAL_BIAS_PAD_VCLAMP(0x7);
value &= ~MIPI_CAL_BIAS_PAD_VAUXP(0x7);
value |= MIPI_CAL_BIAS_PAD_VCLAMP(soc->pad_vclamp_level);
@@ -426,6 +511,7 @@ static int tegra_mipi_probe(struct platform_device *pdev)
return -ENOMEM;
mipi->soc = match->data;
+ mipi->dev = &pdev->dev;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
mipi->regs = devm_ioremap_resource(&pdev->dev, res);