[RFC,v2 6/6] media: ds90ub953: new driver for TI DS90UB953-Q1 video serializer

[Luca Ceresoli <luca@lucaceresoli.net>]

Add a driver for the TI DS90UB953-Q1, a MIPI CSI-2 video serializer that
forwards a MIPI CSI-2 input video stream over an FPD Link 3 connection to a
remote deserializer. It also allows access to I2C and GPIO from the
deserializer.

Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>

---

Changes RFCv1 -> RFCv2: none, this patch is new in RFCv2
---
 drivers/media/i2c/Kconfig     |  10 +
 drivers/media/i2c/Makefile    |   1 +
 drivers/media/i2c/ds90ub953.c | 354 ++++++++++++++++++++++++++++++++++
 3 files changed, 365 insertions(+)
 create mode 100644 drivers/media/i2c/ds90ub953.c

diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
index e7088ccfd280..9db84ebdc060 100644
--- a/drivers/media/i2c/Kconfig
+++ b/drivers/media/i2c/Kconfig
@@ -569,6 +569,16 @@ config VIDEO_DS90UB954
 	  To compile this driver as a module, choose M here: the
 	  module will be called ds90ub954.
 
+config VIDEO_DS90UB953
+	tristate "TI DS90UB953-Q1 serializer"
+	help
+	  Device driver for the Texas Instruments "DS90UB953-Q1
+	  FPD-Link III 4.16-Gbps Serializer With CSI-2 Interface for
+	  2.3MP/60fps Cameras, RADAR, and Other Sensors".
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called ds90ub953.
+
 comment "Camera sensor devices"
 
 config VIDEO_APTINA_PLL
diff --git a/drivers/media/i2c/Makefile b/drivers/media/i2c/Makefile
index 66e52ededa4e..98c124c47be2 100644
--- a/drivers/media/i2c/Makefile
+++ b/drivers/media/i2c/Makefile
@@ -116,5 +116,6 @@ obj-$(CONFIG_VIDEO_IMX355)	+= imx355.o
 obj-$(CONFIG_VIDEO_ST_MIPID02) += st-mipid02.o
 
 obj-$(CONFIG_VIDEO_DS90UB954)	+= ds90ub954.o
+obj-$(CONFIG_VIDEO_DS90UB953)	+= ds90ub953.o
 
 obj-$(CONFIG_SDR_MAX2175) += max2175.o
diff --git a/drivers/media/i2c/ds90ub953.c b/drivers/media/i2c/ds90ub953.c
new file mode 100644
index 000000000000..d88366f81a8d
--- /dev/null
+++ b/drivers/media/i2c/ds90ub953.c
@@ -0,0 +1,354 @@
+// SPDX-License-Identifier: GPL-2.0
+/**
+ * Driver for the Texas Instruments DS90UB953-Q1 video serializer
+ *
+ * Copyright (c) 2019 Luca Ceresoli <luca@lucaceresoli.net>
+ */
+
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/delay.h>
+#include <dt-bindings/media/ds90ub953.h>
+
+#define DS90_NUM_GPIOS			4  /* Physical GPIO pins */
+
+
+#define DS90_REG_DEVICE_ID		0x00
+
+#define DS90_REG_RESET_CTL		0x01
+#define DS90_REG_RESET_CTL_RESTART_AUTOLOAD	BIT(2)
+#define DS90_REG_RESET_CTL_DIGITAL_RESET_1	BIT(1)
+#define DS90_REG_RESET_CTL_DIGITAL_RESET_0	BIT(0)
+
+#define DS90_REG_GENERAL_CFG		0x02
+#define DS90_REG_MODE_SEL		0x03
+#define DS90_REG_BC_MODE_SELECT		0x04
+#define DS90_REG_PLLCLK_CTRL		0x05
+#define DS90_REG_CLKOUT_CTRL0		0x06
+#define DS90_REG_CLKOUT_CTRL1		0x07
+#define DS90_REG_BCC_WATCHDOG		0x08
+#define DS90_REG_I2C_CONTROL1		0x09
+#define DS90_REG_I2C_CONTROL2		0x0A
+#define DS90_REG_SCL_HIGH_TIME		0x0B
+#define DS90_REG_SCL_LOW_TIME		0x0C
+
+#define DS90_REG_LOCAL_GPIO_DATA	0x0D
+#define DS90_REG_LOCAL_GPIO_DATA_RMTEN(n)	BIT((n) + 4)
+#define DS90_REG_LOCAL_GPIO_DATA_OUT_SRC(n)	BIT((n) + 4)
+
+#define DS90_REG_GPIO_INPUT_CTRL	0x0E
+#define DS90_REG_GPIO_INPUT_CTRL_INPUT_EN(n)	BIT((n))
+#define DS90_REG_GPIO_INPUT_CTRL_OUT_EN(n)	BIT((n) + 4)
+
+#define DS90_REG_DVP_CFG		0x10
+#define DS90_REG_DVP_DT			0x11
+#define DS90_REG_FORCE_BIST_ERR		0x13
+#define DS90_REG_REMOTE_BIST_CTRL	0x14
+#define DS90_REG_SENSOR_VGAIN		0x15
+#define DS90_REG_SENSOR_CTRL0		0x17
+#define DS90_REG_SENSOR_CTRL1		0x18
+#define DS90_REG_SENSOR_V0_THRESH	0x19
+#define DS90_REG_SENSOR_V1_THRESH	0x1A
+#define DS90_REG_SENSOR_T_THRESH	0x1B
+#define DS90_REG_SENSOR_T_THRESH	0x1B
+#define DS90_REG_ALARM_CSI_EN		0x1C
+#define DS90_REG_ALARM_SENSE_EN		0x1D
+#define DS90_REG_ALARM_BC_EN		0x1E
+
+#define DS90_REG_CSI_POL_SEL		0x20
+#define DS90_REG_CSI_POL_SEL_POLARITY_CLK0	BIT(4)
+
+#define DS90_REG_CSI_LP_POLARITY	0x21
+#define DS90_REG_CSI_LP_POLARITY_POL_LP_CLK0	BIT(4)
+
+#define DS90_REG_CSI_EN_HSRX		0x22
+#define DS90_REG_CSI_EN_LPRX		0x23
+#define DS90_REG_CSI_EN_RXTERM		0x24
+#define DS90_REG_CSI_PKT_HDR_TINIT_CTRL 0x31
+#define DS90_REG_BCC_CONFIG		0x32
+#define DS90_REG_DATAPATH_CTL1		0x33
+#define DS90_REG_REMOTE_PAR_CAP1	0x35
+#define DS90_REG_DES_ID			0x37
+#define DS90_REG_SLAVE_ID_0		0x39
+#define DS90_REG_SLAVE_ID_1		0x3A
+#define DS90_REG_SLAVE_ID_2		0x3B
+#define DS90_REG_SLAVE_ID_3		0x3C
+#define DS90_REG_SLAVE_ID_4		0x3D
+#define DS90_REG_SLAVE_ID_5		0x3E
+#define DS90_REG_SLAVE_ID_6		0x3F
+#define DS90_REG_SLAVE_ID_7		0x40
+#define DS90_REG_SLAVE_ID_ALIAS_0	0x41
+#define DS90_REG_SLAVE_ID_ALIAS_0	0x41
+#define DS90_REG_SLAVE_ID_ALIAS_1	0x42
+#define DS90_REG_SLAVE_ID_ALIAS_2	0x43
+#define DS90_REG_SLAVE_ID_ALIAS_3	0x44
+#define DS90_REG_SLAVE_ID_ALIAS_4	0x45
+#define DS90_REG_SLAVE_ID_ALIAS_5	0x46
+#define DS90_REG_SLAVE_ID_ALIAS_6	0x47
+#define DS90_REG_SLAVE_ID_ALIAS_7	0x48
+#define DS90_REG_BC_CTRL		0x49
+#define DS90_REG_REV_MASK_ID		0x50
+
+#define DS90_REG_DEVICE_STS		0x51
+#define DS90_REG_DEVICE_STS_CFG_INIT_DONE	BIT(6)
+
+#define DS90_REG_GENERAL_STATUS		0x52
+#define DS90_REG_GPIO_PIN_STS		0x53
+#define DS90_REG_BIST_ERR_CNT		0x54
+#define DS90_REG_CRC_ERR_CNT1		0x55
+#define DS90_REG_CRC_ERR_CNT2		0x56
+#define DS90_REG_SENSOR_STATUS		0x57
+#define DS90_REG_SENSOR_V0		0x58
+#define DS90_REG_SENSOR_V1		0x59
+#define DS90_REG_SENSOR_T		0x5A
+#define DS90_REG_SENSOR_T		0x5A
+#define DS90_REG_CSI_ERR_CNT		0x5C
+#define DS90_REG_CSI_ERR_STATUS		0x5D
+#define DS90_REG_CSI_ERR_DLANE01	0x5E
+#define DS90_REG_CSI_ERR_DLANE23	0x5F
+#define DS90_REG_CSI_ERR_CLK_LANE	0x60
+#define DS90_REG_CSI_PKT_HDR_VC_ID	0x61
+#define DS90_REG_PKT_HDR_WC_LSB		0x62
+#define DS90_REG_PKT_HDR_WC_MSB		0x63
+#define DS90_REG_CSI_ECC		0x64
+#define DS90_REG_IND_ACC_CTL		0xB0
+#define DS90_REG_IND_ACC_ADDR		0xB1
+#define DS90_REG_IND_ACC_DATA		0xB2
+#define DS90_REG_FPD3_RX_ID0		0xF0
+#define DS90_REG_FPD3_RX_ID1		0xF1
+#define DS90_REG_FPD3_RX_ID2		0xF2
+#define DS90_REG_FPD3_RX_ID3		0xF3
+#define DS90_REG_FPD3_RX_ID4		0xF4
+#define DS90_REG_FPD3_RX_ID5		0xF5
+
+struct ds90_data {
+	struct i2c_client      *client;
+
+	u32 gpio_func[DS90_NUM_GPIOS];
+};
+
+/* -----------------------------------------------------------------------------
+ * Basic device access
+ */
+static s32 ds90_read(const struct ds90_data *ds90, u8 reg)
+{
+	s32 ret;
+
+	ret = i2c_smbus_read_byte_data(ds90->client, reg);
+	if (ret < 0)
+		dev_err(&ds90->client->dev, "Cannot read register 0x%02x!\n",
+			reg);
+
+	return ret;
+}
+
+static s32 ds90_write(const struct ds90_data *ds90, u8 reg, u8 val)
+{
+	s32 ret;
+
+	ret = i2c_smbus_write_byte_data(ds90->client, reg, val);
+	if (ret < 0)
+		dev_err(&ds90->client->dev, "Cannot write register 0x%02x!\n",
+			reg);
+
+	return ret;
+}
+
+/* -----------------------------------------------------------------------------
+ * GPIOs
+ */
+
+static int ds90_configure_gpios(struct ds90_data *ds90)
+{
+	struct device *dev = &ds90->client->dev;
+	u8 gpio_input_ctrl = 0;
+	u8 local_gpio_data = 0;
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(ds90->gpio_func); i++) {
+
+		if (ds90->gpio_func[i] >= DS90_GPIO_N_FUNCS) {
+			dev_err(dev,
+				"Unknown gpio-functions value %u, GPIO%d will be unused",
+				ds90->gpio_func[i], i);
+			continue;
+		}
+
+		switch (ds90->gpio_func[i]) {
+		case DS90_GPIO_FUNC_INPUT:
+			gpio_input_ctrl |= DS90_REG_GPIO_INPUT_CTRL_INPUT_EN(i);
+			break;
+		case DS90_GPIO_FUNC_OUTPUT_REMOTE:
+			gpio_input_ctrl |= DS90_REG_GPIO_INPUT_CTRL_OUT_EN(i);
+			local_gpio_data |= DS90_REG_LOCAL_GPIO_DATA_RMTEN(i);
+			break;
+		}
+	}
+
+	ds90_write(ds90, DS90_REG_LOCAL_GPIO_DATA, local_gpio_data);
+	ds90_write(ds90, DS90_REG_GPIO_INPUT_CTRL, gpio_input_ctrl);
+	/* TODO setting DATAPATH_CTL1 is needed for inputs? */
+
+	return 0;
+}
+
+/* -----------------------------------------------------------------------------
+ * Core
+ */
+
+/*
+ * Reset via registers (useful from remote).
+ * Note: the procedure is undocumented, but this one seems to work.
+ */
+static void ds90_soft_reset(struct ds90_data *ds90)
+{
+	int retries = 10;
+	s32 ret;
+
+	while (retries-- > 0) {
+		ret = ds90_write(ds90, DS90_REG_RESET_CTL,
+				 DS90_REG_RESET_CTL_DIGITAL_RESET_1);
+		if (ret >= 0)
+			break;
+		usleep_range(1000, 3000);
+	}
+
+	retries = 10;
+	while (retries-- > 0) {
+		ret = ds90_read(ds90, DS90_REG_DEVICE_STS);
+		if (ret >= 0 && (ret & DS90_REG_DEVICE_STS_CFG_INIT_DONE))
+			break;
+		usleep_range(1000, 3000);
+	}
+}
+
+static int ds90_parse_dt(struct ds90_data *ds90)
+{
+	struct device_node *np = ds90->client->dev.of_node;
+	struct device *dev = &ds90->client->dev;
+	int err;
+
+	if (!np) {
+		dev_err(dev, "OF: no device tree node!\n");
+		return -ENOENT;
+	}
+
+	/* optional, if absent all GPIO pins are unused */
+	err = of_property_read_u32_array(np, "gpio-functions", ds90->gpio_func,
+					ARRAY_SIZE(ds90->gpio_func));
+	if (err && err != -EINVAL)
+		dev_err(dev, "DT: invalid gpio-functions property (%d)", err);
+
+	if (of_property_read_bool(np, "ti,ds90ub953-q1-clk-inv-pol-quirk")) {
+		ds90_write(ds90,
+			   DS90_REG_CSI_POL_SEL,
+			   DS90_REG_CSI_POL_SEL_POLARITY_CLK0);
+		ds90_write(ds90,
+			   DS90_REG_CSI_LP_POLARITY,
+			   DS90_REG_CSI_LP_POLARITY_POL_LP_CLK0);
+	}
+
+	return 0;
+}
+
+static int ds90_probe(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	struct ds90_data *ds90;
+	s32 rev_mask;
+	int err;
+
+	dev_dbg(dev, "probing, addr 0x%02x\n", client->addr);
+
+	ds90 = devm_kzalloc(dev, sizeof(*ds90), GFP_KERNEL);
+	if (!ds90)
+		return -ENOMEM;
+
+	ds90->client = client;
+	i2c_set_clientdata(client, ds90);
+
+	ds90_soft_reset(ds90);
+
+	rev_mask = ds90_read(ds90, DS90_REG_REV_MASK_ID);
+	if (rev_mask < 0) {
+		err = rev_mask;
+		dev_err(dev,
+			"Cannot read first register (%d), abort\n", err);
+		goto err_reg_read;
+	}
+
+	err = ds90_parse_dt(ds90);
+	if (err)
+		goto err_parse_dt;
+
+	/* I2C fast mode 400 kHz */
+	/* TODO compute values from REFCLK */
+	ds90_write(ds90, DS90_REG_SCL_HIGH_TIME, 0x13);
+	ds90_write(ds90, DS90_REG_SCL_LOW_TIME,  0x26);
+
+	/*
+	 * TODO compute these hard-coded values
+	 *
+	 * SET CLK_OUT:
+	 * MODE    = 0 = CSI-2 sync (strap, reg 0x03) -> refclk from deser
+	 * REFCLK  = 23..26 MHz (REFCLK pin @ remote deserializer)
+	 * FC      = fwd channel data rate = 160 x REFCLK
+	 * CLK_OUT = FC * M / (HS_CLK_DIV * N)
+	 *         = FC * 1 / (4 * 20) = 2 * REFCLK
+	 */
+	ds90_write(ds90, DS90_REG_CLKOUT_CTRL0, 0x41); /* div by 4, M=1 */
+	ds90_write(ds90, DS90_REG_CLKOUT_CTRL1,   20); /* N=20 */
+
+	err = ds90_configure_gpios(ds90);
+	if (err)
+		goto err_configure_gpios;
+
+	dev_info(dev, "Successfully probed (rev/mask %02x)\n", rev_mask);
+
+	return 0;
+
+err_configure_gpios:
+err_parse_dt:
+err_reg_read:
+	return err;
+}
+
+static int ds90_remove(struct i2c_client *client)
+{
+	dev_info(&client->dev, "Removing\n");
+	return 0;
+}
+
+static const struct i2c_device_id ds90_id[] = {
+	{ "ds90ub953-q1", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, ds90_id);
+
+#ifdef CONFIG_OF
+static const struct of_device_id ds90_dt_ids[] = {
+	{ .compatible = "ti,ds90ub953-q1", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, ds90_dt_ids);
+#endif
+
+static struct i2c_driver ds90ub953_driver = {
+	.probe_new	= ds90_probe,
+	.remove		= ds90_remove,
+	.id_table	= ds90_id,
+	.driver = {
+		.name	= "ds90ub953",
+		.owner = THIS_MODULE,
+		.of_match_table = of_match_ptr(ds90_dt_ids),
+	},
+};
+
+module_i2c_driver(ds90ub953_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Texas Instruments DS90UB953-Q1 CSI-2 serializer driver");
+MODULE_AUTHOR("Luca Ceresoli <luca@lucaceresoli.net>");
-- 
2.17.1