diff options
| -rw-r--r-- | drivers/gpu/host1x/mipi.c | 110 |
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); |