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

Message ID 20210319062752.145730-6-andrew@aj.id.au
State New
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Series
  • Untitled series #112632
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Commit Message

Andrew Jeffery March 19, 2021, 6:27 a.m.
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@aj.id.au>
---
 drivers/char/ipmi/kcs_bmc_aspeed.c | 146 ++++++++++++++---------------
 1 file changed, 68 insertions(+), 78 deletions(-)

Comments

ChiaWei Wang April 6, 2021, 6:07 a.m. | #1
I have tried this patch on Intel EGS CRB with AST2600 A1 as the BMC.
Chiawei

Tested-by: Chia-Wei Wang <chiawei_wang@aspeedtech.com>

> -----Original Message-----
> From: Andrew Jeffery <andrew@aj.id.au>
> Sent: Friday, March 19, 2021 2:28 PM
> To: openipmi-developer@lists.sourceforge.net; openbmc@lists.ozlabs.org;
> minyard@acm.org
> 
> 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@aj.id.au>
> ---
>  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;
>  	}
> 
> -	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
Zev Weiss April 9, 2021, 3:24 a.m. | #2
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@aj.id.au>
>---
> 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
>

Patch

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;
 	}
 
-	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);