[U-Boot] [PATCH v2 2/3] devinfo: Add gazerbeam board driver

[Mario Six]

Add a board driver for the upcoming gdsys Gazerbeam board.

Signed-off-by: Mario Six <mario.six at gdsys.cc>
---

v1 -> v2:
* Improved error handling
* Renamed DT properties
* Moved the driver over to the board uclass

---
 drivers/board/gazerbeam.c | 173 ++++++++++++++++++++++++++++++++++++++++++++++
 drivers/board/gazerbeam.h |  17 +++++
 2 files changed, 190 insertions(+)
 create mode 100644 drivers/board/gazerbeam.c
 create mode 100644 drivers/board/gazerbeam.h

diff --git a/drivers/board/gazerbeam.c b/drivers/board/gazerbeam.c
new file mode 100644
index 0000000000..b4c2a01d76
--- /dev/null
+++ b/drivers/board/gazerbeam.c
@@ -0,0 +1,173 @@
+/*
+ * (C) Copyright 2017
+ * Mario Six,  Guntermann & Drunck GmbH, mario.six at gdsys.cc
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <board.h>
+#include <i2c.h>
+#include <asm/gpio.h>
+
+#include "gazerbeam.h"
+
+const int VER_GPIOS_COUNT = 4;
+
+struct board_gazerbeam_priv {
+	struct gpio_desc var_gpios[2];
+	struct gpio_desc ver_gpios[4];
+	int variant;
+	int multichannel;
+	int hwversion;
+};
+
+static int _read_multichannel_variant(struct udevice *dev)
+{
+	struct board_gazerbeam_priv *priv = dev_get_priv(dev);
+	struct udevice *i2c_bus;
+	struct udevice *dummy;
+	char *listname;
+	int mc4, mc2, sc, con;
+	int gpio_num;
+	int res;
+
+	res = uclass_get_device_by_seq(UCLASS_I2C, 1, &i2c_bus);
+	if (res) {
+		debug("Could not get I2C bus\n");
+		return res;
+	}
+
+	if (!i2c_bus) {
+		debug("Could not get I2C bus\n");
+		return -EIO;
+	}
+
+	mc2 = !dm_i2c_probe(i2c_bus, 0x20, 0, &dummy);
+	mc4 = !dm_i2c_probe(i2c_bus, 0x22, 0, &dummy);
+
+	if (mc2 && mc4) {
+		debug("Board hardware configuration inconsistent.\n");
+		return -EINVAL;
+	}
+
+	listname = mc2 ? "var-gpios-mc2" : "var-gpios-mc4";
+
+	gpio_num = gpio_request_list_by_name(dev, listname, priv->var_gpios, 2,
+					     GPIOD_IS_IN);
+	if (gpio_num < 0) {
+		debug("Requesting gpio list %s failed.\n", listname);
+		return gpio_num;
+	}
+
+	sc = dm_gpio_get_value(&priv->var_gpios[0]);
+	if (sc < 0) {
+		debug("Error while reading sc GPIO");
+		return sc;
+	}
+
+	con = dm_gpio_get_value(&priv->var_gpios[1]);
+	if (con < 0) {
+		debug("Error while reading con GPIO");
+		return con;
+	}
+
+	if ((sc && mc2) || (sc && mc4) || (!sc && !mc2 && !mc4)) {
+		debug("Board hardware configuration inconsistent.\n");
+		return -EINVAL;
+	}
+
+	priv->variant = con ? VAR_CON : VAR_CPU;
+
+	priv->multichannel = mc4 ? 4 : (mc2 ? 2 : (sc ? 1 : 0));
+
+	return 0;
+}
+
+static int _read_hwversion(struct udevice *dev)
+{
+	struct board_gazerbeam_priv *priv = dev_get_priv(dev);
+	int res;
+
+	if (!gpio_request_list_by_name(dev, "ver-gpios", priv->ver_gpios,
+				       VER_GPIOS_COUNT, GPIOD_IS_IN))
+		return -ENODEV;
+
+	res = dm_gpio_get_values_as_int(priv->ver_gpios, VER_GPIOS_COUNT);
+
+	if (res < 0) {
+		debug("Error while reading HW version from GPIO expander\n");
+		return res;
+	}
+
+	priv->hwversion = res;
+
+	res = gpio_free_list(dev, priv->ver_gpios, VER_GPIOS_COUNT);
+	if (res < 0) {
+		debug("Error while freeing HW version GPIO list\n");
+		return res;
+	}
+
+	return 0;
+}
+
+int board_gazerbeam_detect(struct udevice *dev)
+{
+	int res;
+
+	res = _read_multichannel_variant(dev);
+	if (res)
+		return res;
+
+	res = _read_hwversion(dev);
+	if (res)
+		return res;
+
+	return 0;
+}
+
+int board_gazerbeam_get_int(struct udevice *dev, int id, int *val)
+{
+	struct board_gazerbeam_priv *priv = dev_get_priv(dev);
+
+	switch (id) {
+	case BOARD_MULTICHANNEL:
+		*val = priv->multichannel;
+		break;
+	case BOARD_VARIANT:
+		*val = priv->variant;
+		break;
+	case BOARD_HWVERSION:
+		*val = priv->hwversion;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static const struct udevice_id board_gazerbeam_ids[] = {
+	{ .compatible = "gdsys,board_gazerbeam" },
+	{ /* sentinel */ }
+};
+
+static const struct board_ops board_gazerbeam_ops = {
+	.detect = board_gazerbeam_detect,
+	.get_int = board_gazerbeam_get_int,
+};
+
+int board_gazerbeam_probe(struct udevice *dev)
+{
+	return 0;
+}
+
+U_BOOT_DRIVER(board_gazerbeam) = {
+	.name           = "board_gazerbeam",
+	.id             = UCLASS_BOARD,
+	.of_match       = board_gazerbeam_ids,
+	.ops		= &board_gazerbeam_ops,
+	.priv_auto_alloc_size = sizeof(struct board_gazerbeam_priv),
+	.probe          = board_gazerbeam_probe,
+};
diff --git a/drivers/board/gazerbeam.h b/drivers/board/gazerbeam.h
new file mode 100644
index 0000000000..532001a053
--- /dev/null
+++ b/drivers/board/gazerbeam.h
@@ -0,0 +1,17 @@
+/*
+ * (C) Copyright 2017
+ * Mario Six,  Guntermann & Drunck GmbH, mario.six at gdsys.cc
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+enum {
+	BOARD_MULTICHANNEL,
+	BOARD_VARIANT,
+	BOARD_HWVERSION,
+};
+
+enum {
+	VAR_CON,
+	VAR_CPU,
+};
-- 
2.16.1