gpu: host1x: Add MIPI pad calibration support
This driver adds support to perform calibration of the MIPI pads for CSI
and DSI.
Signed-off-by: Thierry Reding <treding@nvidia.com>
diff --git a/drivers/gpu/host1x/mipi.c b/drivers/gpu/host1x/mipi.c
new file mode 100644
index 0000000..518b98d
--- /dev/null
+++ b/drivers/gpu/host1x/mipi.c
@@ -0,0 +1,272 @@
+/*
+ * Copyright (C) 2013 NVIDIA Corporation
+ *
+ * Permission to use, copy, modify, distribute, and sell this software and its
+ * documentation for any purpose is hereby granted without fee, provided that
+ * the above copyright notice appear in all copies and that both that copyright
+ * notice and this permission notice appear in supporting documentation, and
+ * that the name of the copyright holders not be used in advertising or
+ * publicity pertaining to distribution of the software without specific,
+ * written prior permission. The copyright holders make no representations
+ * about the suitability of this software for any purpose. It is provided "as
+ * is" without express or implied warranty.
+ *
+ * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
+ * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
+ * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
+ * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
+ * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
+ * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
+ * OF THIS SOFTWARE.
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#define MIPI_CAL_CTRL 0x00
+#define MIPI_CAL_CTRL_START (1 << 0)
+
+#define MIPI_CAL_AUTOCAL_CTRL 0x01
+
+#define MIPI_CAL_STATUS 0x02
+#define MIPI_CAL_STATUS_DONE (1 << 16)
+#define MIPI_CAL_STATUS_ACTIVE (1 << 0)
+
+#define MIPI_CAL_CONFIG_CSIA 0x05
+#define MIPI_CAL_CONFIG_CSIB 0x06
+#define MIPI_CAL_CONFIG_CSIC 0x07
+#define MIPI_CAL_CONFIG_CSID 0x08
+#define MIPI_CAL_CONFIG_CSIE 0x09
+#define MIPI_CAL_CONFIG_DSIA 0x0e
+#define MIPI_CAL_CONFIG_DSIB 0x0f
+#define MIPI_CAL_CONFIG_DSIC 0x10
+#define MIPI_CAL_CONFIG_DSID 0x11
+
+#define MIPI_CAL_CONFIG_SELECT (1 << 21)
+#define MIPI_CAL_CONFIG_HSPDOS(x) (((x) & 0x1f) << 16)
+#define MIPI_CAL_CONFIG_HSPUOS(x) (((x) & 0x1f) << 8)
+#define MIPI_CAL_CONFIG_TERMOS(x) (((x) & 0x1f) << 0)
+
+#define MIPI_CAL_BIAS_PAD_CFG0 0x16
+#define MIPI_CAL_BIAS_PAD_PDVCLAMP (1 << 1)
+#define MIPI_CAL_BIAS_PAD_E_VCLAMP_REF (1 << 0)
+
+#define MIPI_CAL_BIAS_PAD_CFG1 0x17
+
+#define MIPI_CAL_BIAS_PAD_CFG2 0x18
+#define MIPI_CAL_BIAS_PAD_PDVREG (1 << 1)
+
+static const struct module {
+ unsigned long reg;
+} modules[] = {
+ { .reg = MIPI_CAL_CONFIG_CSIA },
+ { .reg = MIPI_CAL_CONFIG_CSIB },
+ { .reg = MIPI_CAL_CONFIG_CSIC },
+ { .reg = MIPI_CAL_CONFIG_CSID },
+ { .reg = MIPI_CAL_CONFIG_CSIE },
+ { .reg = MIPI_CAL_CONFIG_DSIA },
+ { .reg = MIPI_CAL_CONFIG_DSIB },
+ { .reg = MIPI_CAL_CONFIG_DSIC },
+ { .reg = MIPI_CAL_CONFIG_DSID },
+};
+
+struct tegra_mipi {
+ void __iomem *regs;
+ struct mutex lock;
+ struct clk *clk;
+};
+
+struct tegra_mipi_device {
+ struct platform_device *pdev;
+ struct tegra_mipi *mipi;
+ struct device *device;
+ unsigned long pads;
+};
+
+static inline unsigned long tegra_mipi_readl(struct tegra_mipi *mipi,
+ unsigned long reg)
+{
+ return readl(mipi->regs + (reg << 2));
+}
+
+static inline void tegra_mipi_writel(struct tegra_mipi *mipi,
+ unsigned long value, unsigned long reg)
+{
+ writel(value, mipi->regs + (reg << 2));
+}
+
+struct tegra_mipi_device *tegra_mipi_request(struct device *device)
+{
+ struct device_node *np = device->of_node;
+ struct tegra_mipi_device *dev;
+ struct of_phandle_args args;
+ int err;
+
+ err = of_parse_phandle_with_args(np, "nvidia,mipi-calibrate",
+ "#nvidia,mipi-calibrate-cells", 0,
+ &args);
+ if (err < 0)
+ return ERR_PTR(err);
+
+ dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+ if (!dev) {
+ of_node_put(args.np);
+ err = -ENOMEM;
+ goto out;
+ }
+
+ dev->pdev = of_find_device_by_node(args.np);
+ if (!dev->pdev) {
+ of_node_put(args.np);
+ err = -ENODEV;
+ goto free;
+ }
+
+ of_node_put(args.np);
+
+ dev->mipi = platform_get_drvdata(dev->pdev);
+ if (!dev->mipi) {
+ err = -EPROBE_DEFER;
+ goto pdev_put;
+ }
+
+ dev->pads = args.args[0];
+ dev->device = device;
+
+ return dev;
+
+pdev_put:
+ platform_device_put(dev->pdev);
+free:
+ kfree(dev);
+out:
+ return ERR_PTR(err);
+}
+EXPORT_SYMBOL(tegra_mipi_request);
+
+void tegra_mipi_free(struct tegra_mipi_device *device)
+{
+ platform_device_put(device->pdev);
+ kfree(device);
+}
+EXPORT_SYMBOL(tegra_mipi_free);
+
+static int tegra_mipi_wait(struct tegra_mipi *mipi)
+{
+ unsigned long timeout = jiffies + msecs_to_jiffies(250);
+ unsigned long value;
+
+ while (time_before(jiffies, timeout)) {
+ value = tegra_mipi_readl(mipi, MIPI_CAL_STATUS);
+ if ((value & MIPI_CAL_STATUS_ACTIVE) == 0 &&
+ (value & MIPI_CAL_STATUS_DONE) != 0)
+ return 0;
+
+ usleep_range(10, 50);
+ }
+
+ return -ETIMEDOUT;
+}
+
+int tegra_mipi_calibrate(struct tegra_mipi_device *device)
+{
+ unsigned long value;
+ unsigned int i;
+ int err;
+
+ err = clk_enable(device->mipi->clk);
+ if (err < 0)
+ return err;
+
+ mutex_lock(&device->mipi->lock);
+
+ value = tegra_mipi_readl(device->mipi, MIPI_CAL_BIAS_PAD_CFG0);
+ value &= ~MIPI_CAL_BIAS_PAD_PDVCLAMP;
+ value |= MIPI_CAL_BIAS_PAD_E_VCLAMP_REF;
+ tegra_mipi_writel(device->mipi, value, MIPI_CAL_BIAS_PAD_CFG0);
+
+ 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);
+
+ for (i = 0; i < ARRAY_SIZE(modules); i++) {
+ if (device->pads & BIT(i))
+ value = MIPI_CAL_CONFIG_SELECT |
+ MIPI_CAL_CONFIG_HSPDOS(0) |
+ MIPI_CAL_CONFIG_HSPUOS(4) |
+ MIPI_CAL_CONFIG_TERMOS(5);
+ else
+ value = 0;
+
+ tegra_mipi_writel(device->mipi, value, modules[i].reg);
+ }
+
+ tegra_mipi_writel(device->mipi, MIPI_CAL_CTRL_START, MIPI_CAL_CTRL);
+
+ err = tegra_mipi_wait(device->mipi);
+
+ mutex_unlock(&device->mipi->lock);
+ clk_disable(device->mipi->clk);
+
+ return err;
+}
+EXPORT_SYMBOL(tegra_mipi_calibrate);
+
+static int tegra_mipi_probe(struct platform_device *pdev)
+{
+ struct tegra_mipi *mipi;
+ struct resource *res;
+ int err;
+
+ mipi = devm_kzalloc(&pdev->dev, sizeof(*mipi), GFP_KERNEL);
+ if (!mipi)
+ return -ENOMEM;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ mipi->regs = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(mipi->regs))
+ return PTR_ERR(mipi->regs);
+
+ mutex_init(&mipi->lock);
+
+ mipi->clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(mipi->clk)) {
+ dev_err(&pdev->dev, "failed to get clock\n");
+ return PTR_ERR(mipi->clk);
+ }
+
+ err = clk_prepare(mipi->clk);
+ if (err < 0)
+ return err;
+
+ platform_set_drvdata(pdev, mipi);
+
+ return 0;
+}
+
+static int tegra_mipi_remove(struct platform_device *pdev)
+{
+ struct tegra_mipi *mipi = platform_get_drvdata(pdev);
+
+ clk_unprepare(mipi->clk);
+
+ return 0;
+}
+
+static struct of_device_id tegra_mipi_of_match[] = {
+ { .compatible = "nvidia,tegra114-mipi", },
+ { },
+};
+
+struct platform_driver tegra_mipi_driver = {
+ .driver = {
+ .name = "tegra-mipi",
+ .of_match_table = tegra_mipi_of_match,
+ },
+ .probe = tegra_mipi_probe,
+ .remove = tegra_mipi_remove,
+};