From 54aa07fdfc01ac5abff342699df269f6f869fbe0 Mon Sep 17 00:00:00 2001
From: Sean Anderson
Date: Tue, 20 Apr 2021 10:50:57 -0400
Subject: sysinfo: Add gpio-sysinfo driver

This uses the newly-added dm_gpio_get_values_as_int_base3 function to
implement a sysinfo device. The revision map is stored in the device tree.

Signed-off-by: Sean Anderson <sean.anderson@seco.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
---
 drivers/sysinfo/gpio.c | 141 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 141 insertions(+)
 create mode 100644 drivers/sysinfo/gpio.c

(limited to 'drivers/sysinfo/gpio.c')

diff --git a/drivers/sysinfo/gpio.c b/drivers/sysinfo/gpio.c
new file mode 100644
index 00000000000..1d7f050998a
--- /dev/null
+++ b/drivers/sysinfo/gpio.c
@@ -0,0 +1,141 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2021 Sean Anderson <sean.anderson@seco.com>
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <log.h>
+#include <sysinfo.h>
+#include <asm/gpio.h>
+#include <dm/device_compat.h>
+
+/**
+ * struct sysinfo_gpio_priv - GPIO sysinfo private data
+ * @gpios: List of GPIOs used to detect the revision
+ * @gpio_num: The number of GPIOs in @gpios
+ * @revision: The revision as detected from the GPIOs.
+ */
+struct sysinfo_gpio_priv {
+	struct gpio_desc *gpios;
+	int gpio_num, revision;
+};
+
+static int sysinfo_gpio_detect(struct udevice *dev)
+{
+	int ret;
+	struct sysinfo_gpio_priv *priv = dev_get_priv(dev);
+
+	ret = dm_gpio_get_values_as_int_base3(priv->gpios, priv->gpio_num);
+	if (ret < 0)
+		return ret;
+
+	priv->revision = ret;
+	return 0;
+}
+
+static int sysinfo_gpio_get_int(struct udevice *dev, int id, int *val)
+{
+	struct sysinfo_gpio_priv *priv = dev_get_priv(dev);
+
+	switch (id) {
+	case SYSINFO_ID_BOARD_MODEL:
+		*val = priv->revision;
+		return 0;
+	default:
+		return -EINVAL;
+	};
+}
+
+static int sysinfo_gpio_get_str(struct udevice *dev, int id, size_t size, char *val)
+{
+	struct sysinfo_gpio_priv *priv = dev_get_priv(dev);
+
+	switch (id) {
+	case SYSINFO_ID_BOARD_MODEL: {
+		const char *name = NULL;
+		int i, ret;
+		u32 revision;
+
+		for (i = 0; i < priv->gpio_num; i++) {
+			ret = dev_read_u32_index(dev, "revisions", i,
+						 &revision);
+			if (ret) {
+				if (ret != -EOVERFLOW)
+					return ret;
+				break;
+			}
+
+			if (revision == priv->revision) {
+				ret = dev_read_string_index(dev, "names", i,
+							    &name);
+				if (ret < 0)
+					return ret;
+				break;
+			}
+		}
+		if (!name)
+			name = "unknown";
+
+		strncpy(val, name, size);
+		val[size - 1] = '\0';
+		return 0;
+	} default:
+		return -EINVAL;
+	};
+}
+
+static const struct sysinfo_ops sysinfo_gpio_ops = {
+	.detect = sysinfo_gpio_detect,
+	.get_int = sysinfo_gpio_get_int,
+	.get_str = sysinfo_gpio_get_str,
+};
+
+static int sysinfo_gpio_probe(struct udevice *dev)
+{
+	int ret;
+	struct sysinfo_gpio_priv *priv = dev_get_priv(dev);
+
+	priv->gpio_num = gpio_get_list_count(dev, "gpios");
+	if (priv->gpio_num < 0) {
+		dev_err(dev, "could not get gpios length (err = %d)\n",
+			priv->gpio_num);
+		return priv->gpio_num;
+	}
+
+	priv->gpios = calloc(priv->gpio_num, sizeof(*priv->gpios));
+	if (!priv->gpios) {
+		dev_err(dev, "could not allocate memory for %d gpios\n",
+			priv->gpio_num);
+		return -ENOMEM;
+	}
+
+	ret = gpio_request_list_by_name(dev, "gpios", priv->gpios,
+					priv->gpio_num, GPIOD_IS_IN);
+	if (ret != priv->gpio_num) {
+		dev_err(dev, "could not get gpios (err = %d)\n",
+			priv->gpio_num);
+		return ret;
+	}
+
+	if (!dev_read_bool(dev, "revisions") || !dev_read_bool(dev, "names")) {
+		dev_err(dev, "revisions or names properties missing\n");
+		return -ENOENT;
+	}
+
+	return 0;
+}
+
+static const struct udevice_id sysinfo_gpio_ids[] = {
+	{ .compatible = "gpio-sysinfo" },
+	{ /* sentinel */ }
+};
+
+U_BOOT_DRIVER(sysinfo_gpio) = {
+	.name           = "sysinfo_gpio",
+	.id             = UCLASS_SYSINFO,
+	.of_match       = sysinfo_gpio_ids,
+	.ops		= &sysinfo_gpio_ops,
+	.priv_auto	= sizeof(struct sysinfo_gpio_priv),
+	.probe          = sysinfo_gpio_probe,
+};
-- 
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