Re: [PATCH v2 06/21] ipmi: kcs_bmc_aspeed: Use of match data to extract KCS properties

[Zev Weiss <zweiss@xxxxxxxxxxx>]

On Fri, Mar 19, 2021 at 01:27:37AM CDT, Andrew Jeffery wrote:
>Unpack and remove the aspeed_kcs_probe_of_v[12]() functions to aid
>rearranging how the private device-driver memory is allocated.
>
>Signed-off-by: Andrew Jeffery <andrew@xxxxxxxx>
>---
> drivers/char/ipmi/kcs_bmc_aspeed.c | 146 ++++++++++++++---------------
> 1 file changed, 68 insertions(+), 78 deletions(-)
>
>diff --git a/drivers/char/ipmi/kcs_bmc_aspeed.c b/drivers/char/ipmi/kcs_bmc_aspeed.c
>index eefe362f65f0..061f53676206 100644
>--- a/drivers/char/ipmi/kcs_bmc_aspeed.c
>+++ b/drivers/char/ipmi/kcs_bmc_aspeed.c
>@@ -13,6 +13,7 @@
> #include <linux/module.h>
> #include <linux/of.h>
> #include <linux/of_address.h>
>+#include <linux/of_device.h>
> #include <linux/platform_device.h>
> #include <linux/poll.h>
> #include <linux/regmap.h>
>@@ -63,6 +64,10 @@ struct aspeed_kcs_bmc {
> 	struct regmap *map;
> };
>
>+struct aspeed_kcs_of_ops {
>+	int (*get_channel)(struct platform_device *pdev);
>+	int (*get_io_address)(struct platform_device *pdev);
>+};
>
> static u8 aspeed_kcs_inb(struct kcs_bmc *kcs_bmc, u32 reg)
> {
>@@ -231,13 +236,10 @@ static const struct kcs_ioreg ast_kcs_bmc_ioregs[KCS_CHANNEL_MAX] = {
> 	{ .idr = LPC_IDR4, .odr = LPC_ODR4, .str = LPC_STR4 },
> };
>
>-static struct kcs_bmc *aspeed_kcs_probe_of_v1(struct platform_device *pdev)
>+static int aspeed_kcs_of_v1_get_channel(struct platform_device *pdev)
> {
>-	struct aspeed_kcs_bmc *priv;
> 	struct device_node *np;
>-	struct kcs_bmc *kcs;
> 	u32 channel;
>-	u32 slave;
> 	int rc;
>
> 	np = pdev->dev.of_node;
>@@ -245,105 +247,78 @@ static struct kcs_bmc *aspeed_kcs_probe_of_v1(struct platform_device *pdev)
> 	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);
>+		return -EINVAL;
> 	}
>
>-	kcs = kcs_bmc_alloc(&pdev->dev, sizeof(struct aspeed_kcs_bmc), channel);
>-	if (!kcs)
>-		return ERR_PTR(-ENOMEM);
>+	return channel;
>+}
>
>-	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);
>-	}
>+static int aspeed_kcs_of_v1_get_io_address(struct platform_device *pdev)
>+{
>+	u32 slave;
>+	int rc;
>
>-	rc = of_property_read_u32(np, "kcs_addr", &slave);
>-	if (rc) {
>+	rc = of_property_read_u32(pdev->dev.of_node, "kcs_addr", &slave);
>+	if (rc || slave > 0xffff) {
> 		dev_err(&pdev->dev, "no valid 'kcs_addr' configured\n");
>-		return ERR_PTR(-EINVAL);
>+		return -EINVAL;
> 	}
>
>-	kcs->ioreg = ast_kcs_bmc_ioregs[channel - 1];
>-	aspeed_kcs_set_address(kcs, slave);
>-
>-	return kcs;
>-}
>-
>-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;
>+	return slave;
> }
>
>-static struct kcs_bmc *aspeed_kcs_probe_of_v2(struct platform_device *pdev)
>+static int aspeed_kcs_of_v2_get_channel(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;
>+	int i;
>
> 	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);
>+		return -EINVAL;
> 	ioreg.idr = be32_to_cpup(reg);
>
> 	reg = of_get_address(np, 1, NULL, NULL);
> 	if (!reg)
>-		return ERR_PTR(-EINVAL);
>+		return -EINVAL;
> 	ioreg.odr = be32_to_cpup(reg);
>
> 	reg = of_get_address(np, 2, NULL, NULL);
> 	if (!reg)
>-		return ERR_PTR(-EINVAL);
>+		return -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);
>-
>-	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(&pdev->dev, "Couldn't get regmap\n");
>-		return ERR_PTR(-ENODEV);
>+	for (i = 0; i < ARRAY_SIZE(ast_kcs_bmc_ioregs); i++) {
>+		if (!memcmp(&ast_kcs_bmc_ioregs[i], &ioreg, sizeof(ioreg)))
>+			return i + 1;

Did some patches perhaps get a bit jumbled during a rebase here or
something?  This patch removes the only initialization of priv->map
I can see, with patch #10 later reintroducing it, but in the interim
it seems like it would be in a fairly broken state (I'm guessing its
removal wasn't really intended to be part of this).

> 	}
>
>-	rc = of_property_read_u32(np, "aspeed,lpc-io-reg", &slave);
>-	if (rc)
>-		return ERR_PTR(rc);
>+	return -EINVAL;
>+}
>
>-	aspeed_kcs_set_address(kcs, slave);
>+static int aspeed_kcs_of_v2_get_io_address(struct platform_device *pdev)
>+{
>+	uint32_t slave;
>+	int rc;
>
>-	return kcs;
>+	rc = of_property_read_u32(pdev->dev.of_node, "aspeed,lpc-io-reg", &slave);
>+	if (rc || slave > 0xffff)
>+		return -EINVAL;
>+
>+	return slave;
> }
>
> static int aspeed_kcs_probe(struct platform_device *pdev)
> {
>+	const struct aspeed_kcs_of_ops *ops;
> 	struct device *dev = &pdev->dev;
> 	struct kcs_bmc *kcs_bmc;
> 	struct device_node *np;
>-	int rc;
>+	int rc, channel, addr;
>
> 	np = dev->of_node->parent;
> 	if (!of_device_is_compatible(np, "aspeed,ast2400-lpc-v2") &&
>@@ -352,23 +327,28 @@ static int aspeed_kcs_probe(struct platform_device *pdev)
> 		dev_err(dev, "unsupported LPC device binding\n");
> 		return -ENODEV;
> 	}
>-
>-	np = 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
>+	ops = of_device_get_match_data(&pdev->dev);
>+	if (!ops)
> 		return -EINVAL;
>
>-	if (IS_ERR(kcs_bmc))
>-		return PTR_ERR(kcs_bmc);
>+	channel = ops->get_channel(pdev);
>+	if (channel < 0)
>+		return channel;
>
>+	kcs_bmc = kcs_bmc_alloc(&pdev->dev, sizeof(struct aspeed_kcs_bmc), channel);
>+	if (!kcs_bmc)
>+		return -ENOMEM;
>+
>+	kcs_bmc->ioreg = ast_kcs_bmc_ioregs[channel - 1];
> 	kcs_bmc->io_inputb = aspeed_kcs_inb;
> 	kcs_bmc->io_outputb = aspeed_kcs_outb;
>
>+	addr = ops->get_io_address(pdev);
>+	if (addr < 0)
>+		return addr;
>+
>+	aspeed_kcs_set_address(kcs_bmc, addr);
>+
> 	rc = aspeed_kcs_config_irq(kcs_bmc, pdev);
> 	if (rc)
> 		return rc;
>@@ -400,11 +380,21 @@ static int aspeed_kcs_remove(struct platform_device *pdev)
> 	return 0;
> }
>
>+static const struct aspeed_kcs_of_ops of_v1_ops = {
>+	.get_channel = aspeed_kcs_of_v1_get_channel,
>+	.get_io_address = aspeed_kcs_of_v1_get_io_address,
>+};
>+
>+static const struct aspeed_kcs_of_ops of_v2_ops = {
>+	.get_channel = aspeed_kcs_of_v2_get_channel,
>+	.get_io_address = aspeed_kcs_of_v2_get_io_address,
>+};
>+
> 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" },
>+	{ .compatible = "aspeed,ast2400-kcs-bmc", .data = &of_v1_ops },
>+	{ .compatible = "aspeed,ast2500-kcs-bmc", .data = &of_v1_ops },
>+	{ .compatible = "aspeed,ast2400-kcs-bmc-v2", .data = &of_v2_ops },
>+	{ .compatible = "aspeed,ast2500-kcs-bmc-v2", .data = &of_v2_ops },
> 	{ }
> };
> MODULE_DEVICE_TABLE(of, ast_kcs_bmc_match);
>-- 
>2.27.0
>