ipmi: kcs: aspeed: Implement v2 bindings

The v2 bindings allow us to extract the resources from the devicetree.
The table in the driver is retained to derive the channel index, which
removes the need for kcs_chan property from the v1 bindings. The v2
bindings allow us to reduce the number of warnings generated by the
existing devicetree nodes.
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Haiyue Wang <haiyue.wang@linux.intel.com>
Message-Id: <01ef3787e9ddaa9d87cfd55a2ac793053b5a69de.1576462051.git-series.andrew@aj.id.au>
Signed-off-by: Corey Minyard <cminyard@mvista.com>

drivers/char/ipmi/kcs_bmc_aspeed.c

@@ -12,6 +12,7 @@
 #include <linux/mfd/syscon.h>
 #include <linux/module.h>
 #include <linux/of.h>
+#include <linux/of_address.h>
 #include <linux/platform_device.h>
 #include <linux/poll.h>
 #include <linux/regmap.h>
@@ -233,38 +234,133 @@ static const struct kcs_ioreg ast_kcs_bmc_ioregs[KCS_CHANNEL_MAX] = {
 	{ .idr = LPC_IDR4, .odr = LPC_ODR4, .str = LPC_STR4 },
 };
 
-static int aspeed_kcs_probe(struct platform_device *pdev)
+static struct kcs_bmc *aspeed_kcs_probe_of_v1(struct platform_device *pdev)
 {
-	struct device *dev = &pdev->dev;
 	struct aspeed_kcs_bmc *priv;
-	struct kcs_bmc *kcs_bmc;
-	u32 chan, addr;
+	struct device_node *np;
+	struct kcs_bmc *kcs;
+	u32 channel;
+	u32 slave;
 	int rc;
 
-	rc = of_property_read_u32(dev->of_node, "kcs_chan", &chan);
-	if ((rc != 0) || (chan == 0 || chan > KCS_CHANNEL_MAX)) {
-		dev_err(dev, "no valid 'kcs_chan' configured\n");
-		return -ENODEV;
+	np = pdev->dev.of_node;
+
+	rc = of_property_read_u32(np, "kcs_chan", &channel);
+	if ((rc != 0) || (channel == 0 || channel > KCS_CHANNEL_MAX)) {
+		dev_err(&pdev->dev, "no valid 'kcs_chan' configured\n");
+		return ERR_PTR(-EINVAL);
 	}
 
-	rc = of_property_read_u32(dev->of_node, "kcs_addr", &addr);
+	kcs = kcs_bmc_alloc(&pdev->dev, sizeof(struct aspeed_kcs_bmc), channel);
+	if (!kcs)
+		return ERR_PTR(-ENOMEM);
+
+	priv = kcs_bmc_priv(kcs);
+	priv->map = syscon_node_to_regmap(pdev->dev.parent->of_node);
+	if (IS_ERR(priv->map)) {
+		dev_err(&pdev->dev, "Couldn't get regmap\n");
+		return ERR_PTR(-ENODEV);
+	}
+
+	rc = of_property_read_u32(np, "kcs_addr", &slave);
 	if (rc) {
-		dev_err(dev, "no valid 'kcs_addr' configured\n");
-		return -ENODEV;
+		dev_err(&pdev->dev, "no valid 'kcs_addr' configured\n");
+		return ERR_PTR(-EINVAL);
 	}
 
-	kcs_bmc = kcs_bmc_alloc(dev, sizeof(*priv), chan);
-	if (!kcs_bmc)
-		return -ENOMEM;
+	kcs->ioreg = ast_kcs_bmc_ioregs[channel - 1];
+	aspeed_kcs_set_address(kcs, slave);
+
+	return 0;
+}
+
+static int aspeed_kcs_calculate_channel(const struct kcs_ioreg *regs)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(ast_kcs_bmc_ioregs); i++) {
+		if (!memcmp(&ast_kcs_bmc_ioregs[i], regs, sizeof(*regs)))
+			return i + 1;
+	}
+
+	return -EINVAL;
+}
+
+static struct kcs_bmc *aspeed_kcs_probe_of_v2(struct platform_device *pdev)
+{
+	struct aspeed_kcs_bmc *priv;
+	struct device_node *np;
+	struct kcs_ioreg ioreg;
+	struct kcs_bmc *kcs;
+	const __be32 *reg;
+	int channel;
+	u32 slave;
+	int rc;
+
+	np = pdev->dev.of_node;
+
+	/* Don't translate addresses, we want offsets for the regmaps */
+	reg = of_get_address(np, 0, NULL, NULL);
+	if (!reg)
+		return ERR_PTR(-EINVAL);
+	ioreg.idr = be32_to_cpup(reg);
+
+	reg = of_get_address(np, 1, NULL, NULL);
+	if (!reg)
+		return ERR_PTR(-EINVAL);
+	ioreg.odr = be32_to_cpup(reg);
+
+	reg = of_get_address(np, 2, NULL, NULL);
+	if (!reg)
+		return ERR_PTR(-EINVAL);
+	ioreg.str = be32_to_cpup(reg);
+
+	channel = aspeed_kcs_calculate_channel(&ioreg);
+	if (channel < 0)
+		return ERR_PTR(channel);
+
+	kcs = kcs_bmc_alloc(&pdev->dev, sizeof(struct aspeed_kcs_bmc), channel);
+	if (!kcs)
+		return ERR_PTR(-ENOMEM);
 
-	priv = kcs_bmc_priv(kcs_bmc);
-	priv->map = syscon_node_to_regmap(dev->parent->of_node);
+	kcs->ioreg = ioreg;
+
+	priv = kcs_bmc_priv(kcs);
+	priv->map = syscon_node_to_regmap(pdev->dev.parent->of_node);
 	if (IS_ERR(priv->map)) {
-		dev_err(dev, "Couldn't get regmap\n");
-		return -ENODEV;
+		dev_err(&pdev->dev, "Couldn't get regmap\n");
+		return ERR_PTR(-ENODEV);
 	}
 
-	kcs_bmc->ioreg = ast_kcs_bmc_ioregs[chan - 1];
+	rc = of_property_read_u32(np, "aspeed,lpc-io-reg", &slave);
+	if (rc)
+		return ERR_PTR(rc);
+
+	aspeed_kcs_set_address(kcs, slave);
+
+	return kcs;
+}
+
+static int aspeed_kcs_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct kcs_bmc *kcs_bmc;
+	struct device_node *np;
+	int rc;
+
+	np = pdev->dev.of_node;
+	if (of_device_is_compatible(np, "aspeed,ast2400-kcs-bmc") ||
+			of_device_is_compatible(np, "aspeed,ast2500-kcs-bmc"))
+		kcs_bmc = aspeed_kcs_probe_of_v1(pdev);
+	else if (of_device_is_compatible(np, "aspeed,ast2400-kcs-bmc-v2") ||
+			of_device_is_compatible(np, "aspeed,ast2500-kcs-bmc-v2"))
+		kcs_bmc = aspeed_kcs_probe_of_v2(pdev);
+	else
+		return -EINVAL;
+
+	if (IS_ERR(kcs_bmc))
+		return PTR_ERR(kcs_bmc);
+
 	kcs_bmc->io_inputb = aspeed_kcs_inb;
 	kcs_bmc->io_outputb = aspeed_kcs_outb;
 
@@ -274,7 +370,6 @@ static int aspeed_kcs_probe(struct platform_device *pdev)
 
 	dev_set_drvdata(dev, kcs_bmc);
 
-	aspeed_kcs_set_address(kcs_bmc, addr);
 	aspeed_kcs_enable_channel(kcs_bmc, true);
 
 	rc = misc_register(&kcs_bmc->miscdev);
@@ -283,9 +378,10 @@ static int aspeed_kcs_probe(struct platform_device *pdev)
 		return rc;
 	}
 
-	pr_info("channel=%u addr=0x%x idr=0x%x odr=0x%x str=0x%x\n",
-		chan, addr,
-		kcs_bmc->ioreg.idr, kcs_bmc->ioreg.odr, kcs_bmc->ioreg.str);
+	dev_dbg(&pdev->dev,
+		"Probed KCS device %d (IDR=0x%x, ODR=0x%x, STR=0x%x)\n",
+		kcs_bmc->channel, kcs_bmc->ioreg.idr, kcs_bmc->ioreg.odr,
+		kcs_bmc->ioreg.str);
 
 	return 0;
 }
@@ -302,6 +398,8 @@ static int aspeed_kcs_remove(struct platform_device *pdev)
 static const struct of_device_id ast_kcs_bmc_match[] = {
 	{ .compatible = "aspeed,ast2400-kcs-bmc" },
 	{ .compatible = "aspeed,ast2500-kcs-bmc" },
+	{ .compatible = "aspeed,ast2400-kcs-bmc-v2" },
+	{ .compatible = "aspeed,ast2500-kcs-bmc-v2" },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, ast_kcs_bmc_match);