board: Add gazerbeam driver

Add a board driver for the upcoming gdsys Gazerbeam board.

Signed-off-by: Mario Six <mario.six@gdsys.cc>
Reviewed-by: Simon Glass <sjg@chromium.org>

3 files changed, 290 insertions, 0 deletions

diff --git a/drivers/board/Kconfig b/drivers/board/Kconfig
index c9a52dc20e..cc1cf27205 100644
--- a/drivers/board/Kconfig
+++ b/drivers/board/Kconfig
@@ -5,3 +5,13 @@ menuconfig BOARD
 	  mechanisms (e.g. reading GPIO values, determining the presence of
 	  devices on busses, etc.). This enables the usage of U-Boot with
 	  modular board architectures.
+
+if BOARD
+
+
+config BOARD_GAZERBEAM
+	bool "Enable device information for the Gazerbeam board"
+	help
+	  Support querying device information for the gdsys Gazerbeam board.
+
+endif
diff --git a/drivers/board/gazerbeam.c b/drivers/board/gazerbeam.c
new file mode 100644
index 0000000000..481cce8e80
--- /dev/null
+++ b/drivers/board/gazerbeam.c
@@ -0,0 +1,262 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2017
+ * Mario Six, Guntermann & Drunck GmbH, mario.six@gdsys.cc
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <board.h>
+#include <i2c.h>
+#include <asm/gpio.h>
+
+#include "gazerbeam.h"
+
+/* Sequence number of I2C bus that holds the GPIO expanders */
+static const int I2C_BUS_SEQ_NO = 1;
+
+/* I2C address of SC/MC2 expander */
+static const int MC2_EXPANDER_ADDR = 0x20;
+/* I2C address of MC4 expander */
+static const int MC4_EXPANDER_ADDR = 0x22;
+
+/* Number of the GPIO to read the SC data from */
+static const int SC_GPIO_NO;
+/* Number of the GPIO to read the CON data from */
+static const int CON_GPIO_NO = 1;
+
+/**
+ * struct board_gazerbeam_priv - Private data structure for the gazerbeam board
+ *				 driver.
+ * @reset_gpios:  GPIOs for the board's reset GPIOs.
+ * @var_gpios:	  GPIOs for the board's hardware variant GPIOs
+ * @ver_gpios:	  GPIOs for the board's hardware version GPIOs
+ * @variant:	  Container for the board's hardware variant (CON/CPU)
+ * @multichannel: Container for the board's multichannel variant (MC4/MC2/SC)
+ * @hwversion:	  Container for the board's hardware version
+ */
+struct board_gazerbeam_priv {
+	struct gpio_desc reset_gpios[2];
+	struct gpio_desc var_gpios[2];
+	struct gpio_desc ver_gpios[4];
+	int variant;
+	int multichannel;
+	int hwversion;
+};
+
+/**
+ * _read_board_variant_data() - Read variant information from the hardware.
+ * @dev: The board device for which to determine the multichannel and device
+ *	 type information.
+ *
+ * The data read from the board's hardware (mostly hard-wired GPIOs) is stored
+ * in the private data structure of the driver to be used by other driver
+ * methods.
+ *
+ * Return: 0 if OK, -ve on error.
+ */
+static int _read_board_variant_data(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, I2C_BUS_SEQ_NO, &i2c_bus);
+	if (res) {
+		debug("%s: Could not get I2C bus %d (err = %d)\n",
+		      dev->name, I2C_BUS_SEQ_NO, res);
+		return res;
+	}
+
+	if (!i2c_bus) {
+		debug("%s: Could not get I2C bus %d\n",
+		      dev->name, I2C_BUS_SEQ_NO);
+		return -EIO;
+	}
+
+	mc2 = !dm_i2c_probe(i2c_bus, MC2_EXPANDER_ADDR, 0, &dummy);
+	mc4 = !dm_i2c_probe(i2c_bus, MC4_EXPANDER_ADDR, 0, &dummy);
+
+	if (mc2 && mc4) {
+		debug("%s: Board hardware configuration inconsistent.\n",
+		      dev->name);
+		return -EINVAL;
+	}
+
+	listname = mc2 ? "var-gpios-mc2" : "var-gpios-mc4";
+
+	gpio_num = gpio_request_list_by_name(dev, listname, priv->var_gpios,
+					     ARRAY_SIZE(priv->var_gpios),
+					     GPIOD_IS_IN);
+	if (gpio_num < 0) {
+		debug("%s: Requesting gpio list %s failed (err = %d).\n",
+		      dev->name, listname, gpio_num);
+		return gpio_num;
+	}
+
+	sc = dm_gpio_get_value(&priv->var_gpios[SC_GPIO_NO]);
+	if (sc < 0) {
+		debug("%s: Error while reading 'sc' GPIO (err = %d)",
+		      dev->name, sc);
+		return sc;
+	}
+
+	con = dm_gpio_get_value(&priv->var_gpios[CON_GPIO_NO]);
+	if (con < 0) {
+		debug("%s: Error while reading 'con' GPIO (err = %d)",
+		      dev->name, con);
+		return con;
+	}
+
+	if ((sc && mc2) || (sc && mc4) || (!sc && !mc2 && !mc4)) {
+		debug("%s: Board hardware configuration inconsistent.\n",
+		      dev->name);
+		return -EINVAL;
+	}
+
+	priv->variant = con ? VAR_CON : VAR_CPU;
+
+	priv->multichannel = mc4 ? 4 : (mc2 ? 2 : (sc ? 1 : 0));
+
+	return 0;
+}
+
+/**
+ * _read_hwversion() - Read the hardware version from the board.
+ * @dev: The board device for which to read the hardware version.
+ *
+ * The hardware version read from the board (from hard-wired GPIOs) is stored
+ * in the private data structure of the driver to be used by other driver
+ * methods.
+ *
+ * Return: 0 if OK, -ve on error.
+ */
+static int _read_hwversion(struct udevice *dev)
+{
+	struct board_gazerbeam_priv *priv = dev_get_priv(dev);
+	int res;
+
+	res = gpio_request_list_by_name(dev, "ver-gpios", priv->ver_gpios,
+					ARRAY_SIZE(priv->ver_gpios),
+					GPIOD_IS_IN);
+	if (res < 0) {
+		debug("%s: Error getting GPIO list 'ver-gpios' (err = %d)\n",
+		      dev->name, res);
+		return -ENODEV;
+	}
+
+	res = dm_gpio_get_values_as_int(priv->ver_gpios,
+					ARRAY_SIZE(priv->ver_gpios));
+	if (res < 0) {
+		debug("%s: Error reading HW version from expander (err = %d)\n",
+		      dev->name, res);
+		return res;
+	}
+
+	priv->hwversion = res;
+
+	res = gpio_free_list(dev, priv->ver_gpios, ARRAY_SIZE(priv->ver_gpios));
+	if (res < 0) {
+		debug("%s: Error freeing HW version GPIO list (err = %d)\n",
+		      dev->name, res);
+		return res;
+	}
+
+	return 0;
+}
+
+static int board_gazerbeam_detect(struct udevice *dev)
+{
+	int res;
+
+	res = _read_board_variant_data(dev);
+	if (res) {
+		debug("%s: Error reading multichannel variant (err = %d)\n",
+		      dev->name, res);
+		return res;
+	}
+
+	res = _read_hwversion(dev);
+	if (res) {
+		debug("%s: Error reading hardware version (err = %d)\n",
+		      dev->name, res);
+		return res;
+	}
+
+	return 0;
+}
+
+static 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:
+		debug("%s: Integer value %d unknown\n", dev->name, id);
+		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,
+};
+
+static int board_gazerbeam_probe(struct udevice *dev)
+{
+	struct board_gazerbeam_priv *priv = dev_get_priv(dev);
+	int gpio_num, i;
+
+	gpio_num = gpio_request_list_by_name(dev, "reset-gpios",
+					     priv->reset_gpios,
+					     ARRAY_SIZE(priv->reset_gpios),
+					     GPIOD_IS_OUT);
+
+	if (gpio_num < 0) {
+		debug("%s: Error getting GPIO list 'reset-gpios' (err = %d)\n",
+		      dev->name, gpio_num);
+		return gpio_num;
+	}
+
+	/* Set startup-finished GPIOs */
+	for (i = 0; i < ARRAY_SIZE(priv->reset_gpios); i++) {
+		int res = dm_gpio_set_value(&priv->reset_gpios[i], 0);
+
+		if (res) {
+			debug("%s: Error while setting GPIO %d (err = %d)\n",
+			      dev->name, i, res);
+			return res;
+		}
+	}
+
+	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..0ca003a373
--- /dev/null
+++ b/drivers/board/gazerbeam.h
@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * (C) Copyright 2017
+ * Mario Six,  Guntermann & Drunck GmbH, mario.six@gdsys.cc
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+enum {
+	BOARD_MULTICHANNEL,
+	BOARD_VARIANT,
+	BOARD_HWVERSION,
+};
+
+enum {
+	VAR_CON,
+	VAR_CPU,
+};