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* [PATCH v4 00/16] ipmi: Allow raw access to KCS devices
@ 2021-06-08 10:47 Andrew Jeffery
  2021-06-08 10:47 ` [PATCH v4 01/16] ipmi: kcs_bmc_aspeed: Use of match data to extract KCS properties Andrew Jeffery
                   ` (16 more replies)
  0 siblings, 17 replies; 23+ messages in thread
From: Andrew Jeffery @ 2021-06-08 10:47 UTC (permalink / raw)
  To: openipmi-developer, openbmc, minyard
  Cc: devicetree, tmaimon77, linux-aspeed, avifishman70, venture,
	linux-kernel, tali.perry1, robh+dt, chiawei_wang,
	linux-arm-kernel, benjaminfair, arnd, zweiss, joel, KWLIU


Hello,

This is the 4th spin of the series refactoring the keyboard-controller-style
device drivers in the IPMI subsystem.

v3 can be found at:

https://lore.kernel.org/lkml/20210510054213.1610760-1-andrew@aj.id.au/

v4:

* Makes kcs_bmc_add_device() return an error if no client successfully
  initialised with respect to the binding of the device driver
* Retains the existing single-open semantics (v3 allowed multiple-open)
* Fixes the OBE macro for the NPCM7xx KCS driver
* Cleans up Yoda-style masks (mask constant on the LHS rather than RHS)
* Cleans up includes in kcs_bmc_client.h
* Adds some comments to the SerIO adapter to clarify object lifetimes

Previously:

Changes in v3:

* The series was rebased onto v5.13-rc1
* v5.13-rc1 includes Chiawei's patches reworking the LPC devicetree bindings,
  so they're no-longer required in the series.
* After some discussion with Arnd[1] and investigating the serio subsystem,
  I've replaced the "raw" KCS driver (patch 16/21 in v2) with a serio adaptor
  (patch 11/16 in this series). The adaptor allows us to take advantage of the
  existing chardevs provided by serio.

[1] https://lore.kernel.org/linux-arm-kernel/37e75b07-a5c6-422f-84b3-54f2bea0b917@www.fastmail.com/

Changes in v2 include:

* A rebase onto v5.12-rc2
* Incorporation of off-list feedback on SerIRQ configuration from
  Chiawei
* Further validation on hardware for ASPEED KCS devices 2, 3 and 4
* Lifting the existing single-open constraint of the IPMI chardev
* Fixes addressing Rob's feedback on the conversion of the ASPEED KCS
  binding to dt-schema
* Fixes addressing Rob's feedback on the new aspeed,lpc-interrupts
  property definition for the ASPEED KCS binding

Please test and review!

Andrew

Andrew Jeffery (16):
  ipmi: kcs_bmc_aspeed: Use of match data to extract KCS properties
  ipmi: kcs_bmc: Make status update atomic
  ipmi: kcs_bmc: Rename {read,write}_{status,data}() functions
  ipmi: kcs_bmc: Split out kcs_bmc_cdev_ipmi
  ipmi: kcs_bmc: Turn the driver data-structures inside-out
  ipmi: kcs_bmc: Split headers into device and client
  ipmi: kcs_bmc: Strip private client data from struct kcs_bmc
  ipmi: kcs_bmc: Decouple the IPMI chardev from the core
  ipmi: kcs_bmc: Allow clients to control KCS IRQ state
  ipmi: kcs_bmc: Enable IBF on open
  ipmi: kcs_bmc: Add serio adaptor
  dt-bindings: ipmi: Convert ASPEED KCS binding to schema
  dt-bindings: ipmi: Add optional SerIRQ property to ASPEED KCS devices
  ipmi: kcs_bmc_aspeed: Implement KCS SerIRQ configuration
  ipmi: kcs_bmc_aspeed: Fix IBFIE typo from datasheet
  ipmi: kcs_bmc_aspeed: Optionally apply status address

 .../bindings/ipmi/aspeed,ast2400-kcs-bmc.yaml | 106 +++
 .../bindings/ipmi/aspeed-kcs-bmc.txt          |  33 -
 drivers/char/ipmi/Kconfig                     |  27 +
 drivers/char/ipmi/Makefile                    |   2 +
 drivers/char/ipmi/kcs_bmc.c                   | 523 ++++-----------
 drivers/char/ipmi/kcs_bmc.h                   |  92 +--
 drivers/char/ipmi/kcs_bmc_aspeed.c            | 633 +++++++++++++-----
 drivers/char/ipmi/kcs_bmc_cdev_ipmi.c         | 568 ++++++++++++++++
 drivers/char/ipmi/kcs_bmc_client.h            |  45 ++
 drivers/char/ipmi/kcs_bmc_device.h            |  22 +
 drivers/char/ipmi/kcs_bmc_npcm7xx.c           |  92 ++-
 drivers/char/ipmi/kcs_bmc_serio.c             | 157 +++++
 12 files changed, 1594 insertions(+), 706 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/ipmi/aspeed,ast2400-kcs-bmc.yaml
 delete mode 100644 Documentation/devicetree/bindings/ipmi/aspeed-kcs-bmc.txt
 create mode 100644 drivers/char/ipmi/kcs_bmc_cdev_ipmi.c
 create mode 100644 drivers/char/ipmi/kcs_bmc_client.h
 create mode 100644 drivers/char/ipmi/kcs_bmc_device.h
 create mode 100644 drivers/char/ipmi/kcs_bmc_serio.c

-- 
2.30.2


^ permalink raw reply	[flat|nested] 23+ messages in thread

* [PATCH v4 01/16] ipmi: kcs_bmc_aspeed: Use of match data to extract KCS properties
  2021-06-08 10:47 [PATCH v4 00/16] ipmi: Allow raw access to KCS devices Andrew Jeffery
@ 2021-06-08 10:47 ` Andrew Jeffery
  2021-06-18 23:19   ` Zev Weiss
  2021-06-08 10:47 ` [PATCH v4 02/16] ipmi: kcs_bmc: Make status update atomic Andrew Jeffery
                   ` (15 subsequent siblings)
  16 siblings, 1 reply; 23+ messages in thread
From: Andrew Jeffery @ 2021-06-08 10:47 UTC (permalink / raw)
  To: openipmi-developer, openbmc, minyard
  Cc: devicetree, tmaimon77, linux-aspeed, avifishman70, venture,
	linux-kernel, tali.perry1, robh+dt, chiawei_wang,
	linux-arm-kernel, benjaminfair, arnd, zweiss, joel, KWLIU

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 | 154 ++++++++++++++---------------
 1 file changed, 77 insertions(+), 77 deletions(-)

diff --git a/drivers/char/ipmi/kcs_bmc_aspeed.c b/drivers/char/ipmi/kcs_bmc_aspeed.c
index eefe362f65f0..69be873f40ac 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 +247,81 @@ 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);
+	for (i = 0; i < ARRAY_SIZE(ast_kcs_bmc_ioregs); i++) {
+		if (!memcmp(&ast_kcs_bmc_ioregs[i], &ioreg, sizeof(ioreg)))
+			return i + 1;
+	}
 
-	kcs = kcs_bmc_alloc(&pdev->dev, sizeof(struct aspeed_kcs_bmc), channel);
-	if (!kcs)
-		return ERR_PTR(-ENOMEM);
+	return -EINVAL;
+}
 
-	kcs->ioreg = ioreg;
+static int aspeed_kcs_of_v2_get_io_address(struct platform_device *pdev)
+{
+	uint32_t slave;
+	int rc;
 
-	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(pdev->dev.of_node, "aspeed,lpc-io-reg", &slave);
+	if (rc || slave > 0xffff) {
+		dev_err(&pdev->dev, "no valid 'aspeed,lpc-io-reg' configured\n");
+		return -EINVAL;
 	}
 
-	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;
+	return slave;
 }
 
 static int aspeed_kcs_probe(struct platform_device *pdev)
 {
+	const struct aspeed_kcs_of_ops *ops;
 	struct device *dev = &pdev->dev;
+	struct aspeed_kcs_bmc *priv;
 	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 +330,35 @@ 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;
+
+	priv = kcs_bmc_priv(kcs_bmc);
+	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 -ENODEV;
+	}
+
+	aspeed_kcs_set_address(kcs_bmc, addr);
+
 	rc = aspeed_kcs_config_irq(kcs_bmc, pdev);
 	if (rc)
 		return rc;
@@ -400,11 +390,21 @@ 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);
-- 
2.30.2


^ permalink raw reply related	[flat|nested] 23+ messages in thread

* [PATCH v4 02/16] ipmi: kcs_bmc: Make status update atomic
  2021-06-08 10:47 [PATCH v4 00/16] ipmi: Allow raw access to KCS devices Andrew Jeffery
  2021-06-08 10:47 ` [PATCH v4 01/16] ipmi: kcs_bmc_aspeed: Use of match data to extract KCS properties Andrew Jeffery
@ 2021-06-08 10:47 ` Andrew Jeffery
  2021-06-08 10:47 ` [PATCH v4 03/16] ipmi: kcs_bmc: Rename {read,write}_{status,data}() functions Andrew Jeffery
                   ` (14 subsequent siblings)
  16 siblings, 0 replies; 23+ messages in thread
From: Andrew Jeffery @ 2021-06-08 10:47 UTC (permalink / raw)
  To: openipmi-developer, openbmc, minyard
  Cc: devicetree, tmaimon77, linux-aspeed, avifishman70, venture,
	linux-kernel, tali.perry1, robh+dt, chiawei_wang,
	linux-arm-kernel, benjaminfair, arnd, zweiss, joel, KWLIU

Enable more efficient implementation of read-modify-write sequences.
Both device drivers for the KCS BMC stack use regmaps. The new callback
allows us to exploit regmap_update_bits().

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Reviewed-by: Zev Weiss <zweiss@equinix.com>
---
 drivers/char/ipmi/kcs_bmc.c         |  7 +------
 drivers/char/ipmi/kcs_bmc.h         |  1 +
 drivers/char/ipmi/kcs_bmc_aspeed.c  |  9 +++++++++
 drivers/char/ipmi/kcs_bmc_npcm7xx.c | 10 ++++++++++
 4 files changed, 21 insertions(+), 6 deletions(-)

diff --git a/drivers/char/ipmi/kcs_bmc.c b/drivers/char/ipmi/kcs_bmc.c
index f292e74bd4a5..58fb1a7bd50d 100644
--- a/drivers/char/ipmi/kcs_bmc.c
+++ b/drivers/char/ipmi/kcs_bmc.c
@@ -67,12 +67,7 @@ static inline void write_status(struct kcs_bmc *kcs_bmc, u8 data)
 
 static void update_status_bits(struct kcs_bmc *kcs_bmc, u8 mask, u8 val)
 {
-	u8 tmp = read_status(kcs_bmc);
-
-	tmp &= ~mask;
-	tmp |= val & mask;
-
-	write_status(kcs_bmc, tmp);
+	kcs_bmc->io_updateb(kcs_bmc, kcs_bmc->ioreg.str, mask, val);
 }
 
 static inline void set_state(struct kcs_bmc *kcs_bmc, u8 state)
diff --git a/drivers/char/ipmi/kcs_bmc.h b/drivers/char/ipmi/kcs_bmc.h
index eb9ea4ce78b8..970f53892f2d 100644
--- a/drivers/char/ipmi/kcs_bmc.h
+++ b/drivers/char/ipmi/kcs_bmc.h
@@ -76,6 +76,7 @@ struct kcs_bmc {
 	struct kcs_ioreg ioreg;
 	u8 (*io_inputb)(struct kcs_bmc *kcs_bmc, u32 reg);
 	void (*io_outputb)(struct kcs_bmc *kcs_bmc, u32 reg, u8 b);
+	void (*io_updateb)(struct kcs_bmc *kcs_bmc, u32 reg, u8 mask, u8 val);
 
 	enum kcs_phases phase;
 	enum kcs_errors error;
diff --git a/drivers/char/ipmi/kcs_bmc_aspeed.c b/drivers/char/ipmi/kcs_bmc_aspeed.c
index 69be873f40ac..01ebb9da3d49 100644
--- a/drivers/char/ipmi/kcs_bmc_aspeed.c
+++ b/drivers/char/ipmi/kcs_bmc_aspeed.c
@@ -90,6 +90,14 @@ static void aspeed_kcs_outb(struct kcs_bmc *kcs_bmc, u32 reg, u8 data)
 	WARN(rc != 0, "regmap_write() failed: %d\n", rc);
 }
 
+static void aspeed_kcs_updateb(struct kcs_bmc *kcs_bmc, u32 reg, u8 mask, u8 val)
+{
+	struct aspeed_kcs_bmc *priv = kcs_bmc_priv(kcs_bmc);
+	int rc;
+
+	rc = regmap_update_bits(priv->map, reg, mask, val);
+	WARN(rc != 0, "regmap_update_bits() failed: %d\n", rc);
+}
 
 /*
  * AST_usrGuide_KCS.pdf
@@ -345,6 +353,7 @@ static int aspeed_kcs_probe(struct platform_device *pdev)
 	kcs_bmc->ioreg = ast_kcs_bmc_ioregs[channel - 1];
 	kcs_bmc->io_inputb = aspeed_kcs_inb;
 	kcs_bmc->io_outputb = aspeed_kcs_outb;
+	kcs_bmc->io_updateb = aspeed_kcs_updateb;
 
 	addr = ops->get_io_address(pdev);
 	if (addr < 0)
diff --git a/drivers/char/ipmi/kcs_bmc_npcm7xx.c b/drivers/char/ipmi/kcs_bmc_npcm7xx.c
index 722f7391fe1f..1f44aadec9e8 100644
--- a/drivers/char/ipmi/kcs_bmc_npcm7xx.c
+++ b/drivers/char/ipmi/kcs_bmc_npcm7xx.c
@@ -97,6 +97,15 @@ static void npcm7xx_kcs_outb(struct kcs_bmc *kcs_bmc, u32 reg, u8 data)
 	WARN(rc != 0, "regmap_write() failed: %d\n", rc);
 }
 
+static void npcm7xx_kcs_updateb(struct kcs_bmc *kcs_bmc, u32 reg, u8 mask, u8 data)
+{
+	struct npcm7xx_kcs_bmc *priv = kcs_bmc_priv(kcs_bmc);
+	int rc;
+
+	rc = regmap_update_bits(priv->map, reg, mask, data);
+	WARN(rc != 0, "regmap_update_bits() failed: %d\n", rc);
+}
+
 static void npcm7xx_kcs_enable_channel(struct kcs_bmc *kcs_bmc, bool enable)
 {
 	struct npcm7xx_kcs_bmc *priv = kcs_bmc_priv(kcs_bmc);
@@ -163,6 +172,7 @@ static int npcm7xx_kcs_probe(struct platform_device *pdev)
 	kcs_bmc->ioreg.str = priv->reg->sts;
 	kcs_bmc->io_inputb = npcm7xx_kcs_inb;
 	kcs_bmc->io_outputb = npcm7xx_kcs_outb;
+	kcs_bmc->io_updateb = npcm7xx_kcs_updateb;
 
 	dev_set_drvdata(dev, kcs_bmc);
 
-- 
2.30.2


^ permalink raw reply related	[flat|nested] 23+ messages in thread

* [PATCH v4 03/16] ipmi: kcs_bmc: Rename {read,write}_{status,data}() functions
  2021-06-08 10:47 [PATCH v4 00/16] ipmi: Allow raw access to KCS devices Andrew Jeffery
  2021-06-08 10:47 ` [PATCH v4 01/16] ipmi: kcs_bmc_aspeed: Use of match data to extract KCS properties Andrew Jeffery
  2021-06-08 10:47 ` [PATCH v4 02/16] ipmi: kcs_bmc: Make status update atomic Andrew Jeffery
@ 2021-06-08 10:47 ` Andrew Jeffery
  2021-06-08 10:47 ` [PATCH v4 04/16] ipmi: kcs_bmc: Split out kcs_bmc_cdev_ipmi Andrew Jeffery
                   ` (13 subsequent siblings)
  16 siblings, 0 replies; 23+ messages in thread
From: Andrew Jeffery @ 2021-06-08 10:47 UTC (permalink / raw)
  To: openipmi-developer, openbmc, minyard
  Cc: devicetree, tmaimon77, linux-aspeed, avifishman70, venture,
	linux-kernel, tali.perry1, robh+dt, chiawei_wang,
	linux-arm-kernel, benjaminfair, arnd, zweiss, joel, KWLIU

Rename the functions in preparation for separating the IPMI chardev out
from the KCS BMC core.

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Reviewed-by: Zev Weiss <zweiss@equinix.com>
---
 drivers/char/ipmi/kcs_bmc.c | 52 ++++++++++++++++++-------------------
 1 file changed, 25 insertions(+), 27 deletions(-)

diff --git a/drivers/char/ipmi/kcs_bmc.c b/drivers/char/ipmi/kcs_bmc.c
index 58fb1a7bd50d..c4336c1f2d6d 100644
--- a/drivers/char/ipmi/kcs_bmc.c
+++ b/drivers/char/ipmi/kcs_bmc.c
@@ -45,42 +45,42 @@ enum kcs_states {
 #define KCS_CMD_WRITE_END         0x62
 #define KCS_CMD_READ_BYTE         0x68
 
-static inline u8 read_data(struct kcs_bmc *kcs_bmc)
+static inline u8 kcs_bmc_read_data(struct kcs_bmc *kcs_bmc)
 {
 	return kcs_bmc->io_inputb(kcs_bmc, kcs_bmc->ioreg.idr);
 }
 
-static inline void write_data(struct kcs_bmc *kcs_bmc, u8 data)
+static inline void kcs_bmc_write_data(struct kcs_bmc *kcs_bmc, u8 data)
 {
 	kcs_bmc->io_outputb(kcs_bmc, kcs_bmc->ioreg.odr, data);
 }
 
-static inline u8 read_status(struct kcs_bmc *kcs_bmc)
+static inline u8 kcs_bmc_read_status(struct kcs_bmc *kcs_bmc)
 {
 	return kcs_bmc->io_inputb(kcs_bmc, kcs_bmc->ioreg.str);
 }
 
-static inline void write_status(struct kcs_bmc *kcs_bmc, u8 data)
+static inline void kcs_bmc_write_status(struct kcs_bmc *kcs_bmc, u8 data)
 {
 	kcs_bmc->io_outputb(kcs_bmc, kcs_bmc->ioreg.str, data);
 }
 
-static void update_status_bits(struct kcs_bmc *kcs_bmc, u8 mask, u8 val)
+static void kcs_bmc_update_status(struct kcs_bmc *kcs_bmc, u8 mask, u8 val)
 {
 	kcs_bmc->io_updateb(kcs_bmc, kcs_bmc->ioreg.str, mask, val);
 }
 
 static inline void set_state(struct kcs_bmc *kcs_bmc, u8 state)
 {
-	update_status_bits(kcs_bmc, KCS_STATUS_STATE_MASK,
+	kcs_bmc_update_status(kcs_bmc, KCS_STATUS_STATE_MASK,
 					KCS_STATUS_STATE(state));
 }
 
 static void kcs_force_abort(struct kcs_bmc *kcs_bmc)
 {
 	set_state(kcs_bmc, ERROR_STATE);
-	read_data(kcs_bmc);
-	write_data(kcs_bmc, KCS_ZERO_DATA);
+	kcs_bmc_read_data(kcs_bmc);
+	kcs_bmc_write_data(kcs_bmc, KCS_ZERO_DATA);
 
 	kcs_bmc->phase = KCS_PHASE_ERROR;
 	kcs_bmc->data_in_avail = false;
@@ -99,9 +99,9 @@ static void kcs_bmc_handle_data(struct kcs_bmc *kcs_bmc)
 	case KCS_PHASE_WRITE_DATA:
 		if (kcs_bmc->data_in_idx < KCS_MSG_BUFSIZ) {
 			set_state(kcs_bmc, WRITE_STATE);
-			write_data(kcs_bmc, KCS_ZERO_DATA);
+			kcs_bmc_write_data(kcs_bmc, KCS_ZERO_DATA);
 			kcs_bmc->data_in[kcs_bmc->data_in_idx++] =
-						read_data(kcs_bmc);
+						kcs_bmc_read_data(kcs_bmc);
 		} else {
 			kcs_force_abort(kcs_bmc);
 			kcs_bmc->error = KCS_LENGTH_ERROR;
@@ -112,7 +112,7 @@ static void kcs_bmc_handle_data(struct kcs_bmc *kcs_bmc)
 		if (kcs_bmc->data_in_idx < KCS_MSG_BUFSIZ) {
 			set_state(kcs_bmc, READ_STATE);
 			kcs_bmc->data_in[kcs_bmc->data_in_idx++] =
-						read_data(kcs_bmc);
+						kcs_bmc_read_data(kcs_bmc);
 			kcs_bmc->phase = KCS_PHASE_WRITE_DONE;
 			kcs_bmc->data_in_avail = true;
 			wake_up_interruptible(&kcs_bmc->queue);
@@ -126,34 +126,34 @@ static void kcs_bmc_handle_data(struct kcs_bmc *kcs_bmc)
 		if (kcs_bmc->data_out_idx == kcs_bmc->data_out_len)
 			set_state(kcs_bmc, IDLE_STATE);
 
-		data = read_data(kcs_bmc);
+		data = kcs_bmc_read_data(kcs_bmc);
 		if (data != KCS_CMD_READ_BYTE) {
 			set_state(kcs_bmc, ERROR_STATE);
-			write_data(kcs_bmc, KCS_ZERO_DATA);
+			kcs_bmc_write_data(kcs_bmc, KCS_ZERO_DATA);
 			break;
 		}
 
 		if (kcs_bmc->data_out_idx == kcs_bmc->data_out_len) {
-			write_data(kcs_bmc, KCS_ZERO_DATA);
+			kcs_bmc_write_data(kcs_bmc, KCS_ZERO_DATA);
 			kcs_bmc->phase = KCS_PHASE_IDLE;
 			break;
 		}
 
-		write_data(kcs_bmc,
+		kcs_bmc_write_data(kcs_bmc,
 			kcs_bmc->data_out[kcs_bmc->data_out_idx++]);
 		break;
 
 	case KCS_PHASE_ABORT_ERROR1:
 		set_state(kcs_bmc, READ_STATE);
-		read_data(kcs_bmc);
-		write_data(kcs_bmc, kcs_bmc->error);
+		kcs_bmc_read_data(kcs_bmc);
+		kcs_bmc_write_data(kcs_bmc, kcs_bmc->error);
 		kcs_bmc->phase = KCS_PHASE_ABORT_ERROR2;
 		break;
 
 	case KCS_PHASE_ABORT_ERROR2:
 		set_state(kcs_bmc, IDLE_STATE);
-		read_data(kcs_bmc);
-		write_data(kcs_bmc, KCS_ZERO_DATA);
+		kcs_bmc_read_data(kcs_bmc);
+		kcs_bmc_write_data(kcs_bmc, KCS_ZERO_DATA);
 		kcs_bmc->phase = KCS_PHASE_IDLE;
 		break;
 
@@ -168,9 +168,9 @@ static void kcs_bmc_handle_cmd(struct kcs_bmc *kcs_bmc)
 	u8 cmd;
 
 	set_state(kcs_bmc, WRITE_STATE);
-	write_data(kcs_bmc, KCS_ZERO_DATA);
+	kcs_bmc_write_data(kcs_bmc, KCS_ZERO_DATA);
 
-	cmd = read_data(kcs_bmc);
+	cmd = kcs_bmc_read_data(kcs_bmc);
 	switch (cmd) {
 	case KCS_CMD_WRITE_START:
 		kcs_bmc->phase = KCS_PHASE_WRITE_START;
@@ -212,7 +212,7 @@ int kcs_bmc_handle_event(struct kcs_bmc *kcs_bmc)
 
 	spin_lock_irqsave(&kcs_bmc->lock, flags);
 
-	status = read_status(kcs_bmc);
+	status = kcs_bmc_read_status(kcs_bmc);
 	if (status & KCS_STATUS_IBF) {
 		if (!kcs_bmc->running)
 			kcs_force_abort(kcs_bmc);
@@ -350,7 +350,7 @@ static ssize_t kcs_bmc_write(struct file *filp, const char __user *buf,
 		kcs_bmc->data_out_idx = 1;
 		kcs_bmc->data_out_len = count;
 		memcpy(kcs_bmc->data_out, kcs_bmc->kbuffer, count);
-		write_data(kcs_bmc, kcs_bmc->data_out[0]);
+		kcs_bmc_write_data(kcs_bmc, kcs_bmc->data_out[0]);
 		ret = count;
 	} else {
 		ret = -EINVAL;
@@ -373,13 +373,11 @@ static long kcs_bmc_ioctl(struct file *filp, unsigned int cmd,
 
 	switch (cmd) {
 	case IPMI_BMC_IOCTL_SET_SMS_ATN:
-		update_status_bits(kcs_bmc, KCS_STATUS_SMS_ATN,
-				   KCS_STATUS_SMS_ATN);
+		kcs_bmc_update_status(kcs_bmc, KCS_STATUS_SMS_ATN, KCS_STATUS_SMS_ATN);
 		break;
 
 	case IPMI_BMC_IOCTL_CLEAR_SMS_ATN:
-		update_status_bits(kcs_bmc, KCS_STATUS_SMS_ATN,
-				   0);
+		kcs_bmc_update_status(kcs_bmc, KCS_STATUS_SMS_ATN, 0);
 		break;
 
 	case IPMI_BMC_IOCTL_FORCE_ABORT:
-- 
2.30.2


^ permalink raw reply related	[flat|nested] 23+ messages in thread

* [PATCH v4 04/16] ipmi: kcs_bmc: Split out kcs_bmc_cdev_ipmi
  2021-06-08 10:47 [PATCH v4 00/16] ipmi: Allow raw access to KCS devices Andrew Jeffery
                   ` (2 preceding siblings ...)
  2021-06-08 10:47 ` [PATCH v4 03/16] ipmi: kcs_bmc: Rename {read,write}_{status,data}() functions Andrew Jeffery
@ 2021-06-08 10:47 ` Andrew Jeffery
  2021-06-08 10:47 ` [PATCH v4 05/16] ipmi: kcs_bmc: Turn the driver data-structures inside-out Andrew Jeffery
                   ` (12 subsequent siblings)
  16 siblings, 0 replies; 23+ messages in thread
From: Andrew Jeffery @ 2021-06-08 10:47 UTC (permalink / raw)
  To: openipmi-developer, openbmc, minyard
  Cc: devicetree, tmaimon77, linux-aspeed, avifishman70, venture,
	linux-kernel, tali.perry1, robh+dt, chiawei_wang,
	linux-arm-kernel, benjaminfair, arnd, zweiss, joel, KWLIU

Take steps towards defining a coherent API to separate the KCS device
drivers from the userspace interface. Decreasing the coupling will
improve the separation of concerns and enable the introduction of
alternative userspace interfaces.

For now, simply split the chardev logic out to a separate file. The code
continues to build into the same module.

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Reviewed-by: Zev Weiss <zweiss@equinix.com>
---
 drivers/char/ipmi/Makefile            |   2 +-
 drivers/char/ipmi/kcs_bmc.c           | 423 +------------------------
 drivers/char/ipmi/kcs_bmc.h           |  10 +-
 drivers/char/ipmi/kcs_bmc_cdev_ipmi.c | 428 ++++++++++++++++++++++++++
 4 files changed, 451 insertions(+), 412 deletions(-)
 create mode 100644 drivers/char/ipmi/kcs_bmc_cdev_ipmi.c

diff --git a/drivers/char/ipmi/Makefile b/drivers/char/ipmi/Makefile
index 0822adc2ec41..a302bc865370 100644
--- a/drivers/char/ipmi/Makefile
+++ b/drivers/char/ipmi/Makefile
@@ -22,7 +22,7 @@ obj-$(CONFIG_IPMI_SSIF) += ipmi_ssif.o
 obj-$(CONFIG_IPMI_POWERNV) += ipmi_powernv.o
 obj-$(CONFIG_IPMI_WATCHDOG) += ipmi_watchdog.o
 obj-$(CONFIG_IPMI_POWEROFF) += ipmi_poweroff.o
-obj-$(CONFIG_IPMI_KCS_BMC) += kcs_bmc.o
+obj-$(CONFIG_IPMI_KCS_BMC) += kcs_bmc.o kcs_bmc_cdev_ipmi.o
 obj-$(CONFIG_ASPEED_BT_IPMI_BMC) += bt-bmc.o
 obj-$(CONFIG_ASPEED_KCS_IPMI_BMC) += kcs_bmc_aspeed.o
 obj-$(CONFIG_NPCM7XX_KCS_IPMI_BMC) += kcs_bmc_npcm7xx.o
diff --git a/drivers/char/ipmi/kcs_bmc.c b/drivers/char/ipmi/kcs_bmc.c
index c4336c1f2d6d..ef5c48ffe74a 100644
--- a/drivers/char/ipmi/kcs_bmc.c
+++ b/drivers/char/ipmi/kcs_bmc.c
@@ -3,446 +3,51 @@
  * Copyright (c) 2015-2018, Intel Corporation.
  */
 
-#define pr_fmt(fmt) "kcs-bmc: " fmt
-
-#include <linux/errno.h>
-#include <linux/io.h>
-#include <linux/ipmi_bmc.h>
 #include <linux/module.h>
-#include <linux/platform_device.h>
-#include <linux/poll.h>
-#include <linux/sched.h>
-#include <linux/slab.h>
 
 #include "kcs_bmc.h"
 
-#define DEVICE_NAME "ipmi-kcs"
-
-#define KCS_MSG_BUFSIZ    1000
-
-#define KCS_ZERO_DATA     0
-
-
-/* IPMI 2.0 - Table 9-1, KCS Interface Status Register Bits */
-#define KCS_STATUS_STATE(state) (state << 6)
-#define KCS_STATUS_STATE_MASK   GENMASK(7, 6)
-#define KCS_STATUS_CMD_DAT      BIT(3)
-#define KCS_STATUS_SMS_ATN      BIT(2)
-#define KCS_STATUS_IBF          BIT(1)
-#define KCS_STATUS_OBF          BIT(0)
-
-/* IPMI 2.0 - Table 9-2, KCS Interface State Bits */
-enum kcs_states {
-	IDLE_STATE  = 0,
-	READ_STATE  = 1,
-	WRITE_STATE = 2,
-	ERROR_STATE = 3,
-};
-
-/* IPMI 2.0 - Table 9-3, KCS Interface Control Codes */
-#define KCS_CMD_GET_STATUS_ABORT  0x60
-#define KCS_CMD_WRITE_START       0x61
-#define KCS_CMD_WRITE_END         0x62
-#define KCS_CMD_READ_BYTE         0x68
-
-static inline u8 kcs_bmc_read_data(struct kcs_bmc *kcs_bmc)
+u8 kcs_bmc_read_data(struct kcs_bmc *kcs_bmc)
 {
 	return kcs_bmc->io_inputb(kcs_bmc, kcs_bmc->ioreg.idr);
 }
+EXPORT_SYMBOL(kcs_bmc_read_data);
 
-static inline void kcs_bmc_write_data(struct kcs_bmc *kcs_bmc, u8 data)
+void kcs_bmc_write_data(struct kcs_bmc *kcs_bmc, u8 data)
 {
 	kcs_bmc->io_outputb(kcs_bmc, kcs_bmc->ioreg.odr, data);
 }
+EXPORT_SYMBOL(kcs_bmc_write_data);
 
-static inline u8 kcs_bmc_read_status(struct kcs_bmc *kcs_bmc)
+u8 kcs_bmc_read_status(struct kcs_bmc *kcs_bmc)
 {
 	return kcs_bmc->io_inputb(kcs_bmc, kcs_bmc->ioreg.str);
 }
+EXPORT_SYMBOL(kcs_bmc_read_status);
 
-static inline void kcs_bmc_write_status(struct kcs_bmc *kcs_bmc, u8 data)
+void kcs_bmc_write_status(struct kcs_bmc *kcs_bmc, u8 data)
 {
 	kcs_bmc->io_outputb(kcs_bmc, kcs_bmc->ioreg.str, data);
 }
+EXPORT_SYMBOL(kcs_bmc_write_status);
 
-static void kcs_bmc_update_status(struct kcs_bmc *kcs_bmc, u8 mask, u8 val)
+void kcs_bmc_update_status(struct kcs_bmc *kcs_bmc, u8 mask, u8 val)
 {
 	kcs_bmc->io_updateb(kcs_bmc, kcs_bmc->ioreg.str, mask, val);
 }
+EXPORT_SYMBOL(kcs_bmc_update_status);
 
-static inline void set_state(struct kcs_bmc *kcs_bmc, u8 state)
-{
-	kcs_bmc_update_status(kcs_bmc, KCS_STATUS_STATE_MASK,
-					KCS_STATUS_STATE(state));
-}
-
-static void kcs_force_abort(struct kcs_bmc *kcs_bmc)
-{
-	set_state(kcs_bmc, ERROR_STATE);
-	kcs_bmc_read_data(kcs_bmc);
-	kcs_bmc_write_data(kcs_bmc, KCS_ZERO_DATA);
-
-	kcs_bmc->phase = KCS_PHASE_ERROR;
-	kcs_bmc->data_in_avail = false;
-	kcs_bmc->data_in_idx = 0;
-}
-
-static void kcs_bmc_handle_data(struct kcs_bmc *kcs_bmc)
-{
-	u8 data;
-
-	switch (kcs_bmc->phase) {
-	case KCS_PHASE_WRITE_START:
-		kcs_bmc->phase = KCS_PHASE_WRITE_DATA;
-		fallthrough;
-
-	case KCS_PHASE_WRITE_DATA:
-		if (kcs_bmc->data_in_idx < KCS_MSG_BUFSIZ) {
-			set_state(kcs_bmc, WRITE_STATE);
-			kcs_bmc_write_data(kcs_bmc, KCS_ZERO_DATA);
-			kcs_bmc->data_in[kcs_bmc->data_in_idx++] =
-						kcs_bmc_read_data(kcs_bmc);
-		} else {
-			kcs_force_abort(kcs_bmc);
-			kcs_bmc->error = KCS_LENGTH_ERROR;
-		}
-		break;
-
-	case KCS_PHASE_WRITE_END_CMD:
-		if (kcs_bmc->data_in_idx < KCS_MSG_BUFSIZ) {
-			set_state(kcs_bmc, READ_STATE);
-			kcs_bmc->data_in[kcs_bmc->data_in_idx++] =
-						kcs_bmc_read_data(kcs_bmc);
-			kcs_bmc->phase = KCS_PHASE_WRITE_DONE;
-			kcs_bmc->data_in_avail = true;
-			wake_up_interruptible(&kcs_bmc->queue);
-		} else {
-			kcs_force_abort(kcs_bmc);
-			kcs_bmc->error = KCS_LENGTH_ERROR;
-		}
-		break;
-
-	case KCS_PHASE_READ:
-		if (kcs_bmc->data_out_idx == kcs_bmc->data_out_len)
-			set_state(kcs_bmc, IDLE_STATE);
-
-		data = kcs_bmc_read_data(kcs_bmc);
-		if (data != KCS_CMD_READ_BYTE) {
-			set_state(kcs_bmc, ERROR_STATE);
-			kcs_bmc_write_data(kcs_bmc, KCS_ZERO_DATA);
-			break;
-		}
-
-		if (kcs_bmc->data_out_idx == kcs_bmc->data_out_len) {
-			kcs_bmc_write_data(kcs_bmc, KCS_ZERO_DATA);
-			kcs_bmc->phase = KCS_PHASE_IDLE;
-			break;
-		}
-
-		kcs_bmc_write_data(kcs_bmc,
-			kcs_bmc->data_out[kcs_bmc->data_out_idx++]);
-		break;
-
-	case KCS_PHASE_ABORT_ERROR1:
-		set_state(kcs_bmc, READ_STATE);
-		kcs_bmc_read_data(kcs_bmc);
-		kcs_bmc_write_data(kcs_bmc, kcs_bmc->error);
-		kcs_bmc->phase = KCS_PHASE_ABORT_ERROR2;
-		break;
-
-	case KCS_PHASE_ABORT_ERROR2:
-		set_state(kcs_bmc, IDLE_STATE);
-		kcs_bmc_read_data(kcs_bmc);
-		kcs_bmc_write_data(kcs_bmc, KCS_ZERO_DATA);
-		kcs_bmc->phase = KCS_PHASE_IDLE;
-		break;
-
-	default:
-		kcs_force_abort(kcs_bmc);
-		break;
-	}
-}
-
-static void kcs_bmc_handle_cmd(struct kcs_bmc *kcs_bmc)
-{
-	u8 cmd;
-
-	set_state(kcs_bmc, WRITE_STATE);
-	kcs_bmc_write_data(kcs_bmc, KCS_ZERO_DATA);
-
-	cmd = kcs_bmc_read_data(kcs_bmc);
-	switch (cmd) {
-	case KCS_CMD_WRITE_START:
-		kcs_bmc->phase = KCS_PHASE_WRITE_START;
-		kcs_bmc->error = KCS_NO_ERROR;
-		kcs_bmc->data_in_avail = false;
-		kcs_bmc->data_in_idx = 0;
-		break;
-
-	case KCS_CMD_WRITE_END:
-		if (kcs_bmc->phase != KCS_PHASE_WRITE_DATA) {
-			kcs_force_abort(kcs_bmc);
-			break;
-		}
-
-		kcs_bmc->phase = KCS_PHASE_WRITE_END_CMD;
-		break;
-
-	case KCS_CMD_GET_STATUS_ABORT:
-		if (kcs_bmc->error == KCS_NO_ERROR)
-			kcs_bmc->error = KCS_ABORTED_BY_COMMAND;
-
-		kcs_bmc->phase = KCS_PHASE_ABORT_ERROR1;
-		kcs_bmc->data_in_avail = false;
-		kcs_bmc->data_in_idx = 0;
-		break;
-
-	default:
-		kcs_force_abort(kcs_bmc);
-		kcs_bmc->error = KCS_ILLEGAL_CONTROL_CODE;
-		break;
-	}
-}
-
+int kcs_bmc_ipmi_event(struct kcs_bmc *kcs_bmc);
 int kcs_bmc_handle_event(struct kcs_bmc *kcs_bmc)
 {
-	unsigned long flags;
-	int ret = -ENODATA;
-	u8 status;
-
-	spin_lock_irqsave(&kcs_bmc->lock, flags);
-
-	status = kcs_bmc_read_status(kcs_bmc);
-	if (status & KCS_STATUS_IBF) {
-		if (!kcs_bmc->running)
-			kcs_force_abort(kcs_bmc);
-		else if (status & KCS_STATUS_CMD_DAT)
-			kcs_bmc_handle_cmd(kcs_bmc);
-		else
-			kcs_bmc_handle_data(kcs_bmc);
-
-		ret = 0;
-	}
-
-	spin_unlock_irqrestore(&kcs_bmc->lock, flags);
-
-	return ret;
+	return kcs_bmc_ipmi_event(kcs_bmc);
 }
 EXPORT_SYMBOL(kcs_bmc_handle_event);
 
-static inline struct kcs_bmc *to_kcs_bmc(struct file *filp)
-{
-	return container_of(filp->private_data, struct kcs_bmc, miscdev);
-}
-
-static int kcs_bmc_open(struct inode *inode, struct file *filp)
-{
-	struct kcs_bmc *kcs_bmc = to_kcs_bmc(filp);
-	int ret = 0;
-
-	spin_lock_irq(&kcs_bmc->lock);
-	if (!kcs_bmc->running)
-		kcs_bmc->running = 1;
-	else
-		ret = -EBUSY;
-	spin_unlock_irq(&kcs_bmc->lock);
-
-	return ret;
-}
-
-static __poll_t kcs_bmc_poll(struct file *filp, poll_table *wait)
-{
-	struct kcs_bmc *kcs_bmc = to_kcs_bmc(filp);
-	__poll_t mask = 0;
-
-	poll_wait(filp, &kcs_bmc->queue, wait);
-
-	spin_lock_irq(&kcs_bmc->lock);
-	if (kcs_bmc->data_in_avail)
-		mask |= EPOLLIN;
-	spin_unlock_irq(&kcs_bmc->lock);
-
-	return mask;
-}
-
-static ssize_t kcs_bmc_read(struct file *filp, char __user *buf,
-			    size_t count, loff_t *ppos)
-{
-	struct kcs_bmc *kcs_bmc = to_kcs_bmc(filp);
-	bool data_avail;
-	size_t data_len;
-	ssize_t ret;
-
-	if (!(filp->f_flags & O_NONBLOCK))
-		wait_event_interruptible(kcs_bmc->queue,
-					 kcs_bmc->data_in_avail);
-
-	mutex_lock(&kcs_bmc->mutex);
-
-	spin_lock_irq(&kcs_bmc->lock);
-	data_avail = kcs_bmc->data_in_avail;
-	if (data_avail) {
-		data_len = kcs_bmc->data_in_idx;
-		memcpy(kcs_bmc->kbuffer, kcs_bmc->data_in, data_len);
-	}
-	spin_unlock_irq(&kcs_bmc->lock);
-
-	if (!data_avail) {
-		ret = -EAGAIN;
-		goto out_unlock;
-	}
-
-	if (count < data_len) {
-		pr_err("channel=%u with too large data : %zu\n",
-			kcs_bmc->channel, data_len);
-
-		spin_lock_irq(&kcs_bmc->lock);
-		kcs_force_abort(kcs_bmc);
-		spin_unlock_irq(&kcs_bmc->lock);
-
-		ret = -EOVERFLOW;
-		goto out_unlock;
-	}
-
-	if (copy_to_user(buf, kcs_bmc->kbuffer, data_len)) {
-		ret = -EFAULT;
-		goto out_unlock;
-	}
-
-	ret = data_len;
-
-	spin_lock_irq(&kcs_bmc->lock);
-	if (kcs_bmc->phase == KCS_PHASE_WRITE_DONE) {
-		kcs_bmc->phase = KCS_PHASE_WAIT_READ;
-		kcs_bmc->data_in_avail = false;
-		kcs_bmc->data_in_idx = 0;
-	} else {
-		ret = -EAGAIN;
-	}
-	spin_unlock_irq(&kcs_bmc->lock);
-
-out_unlock:
-	mutex_unlock(&kcs_bmc->mutex);
-
-	return ret;
-}
-
-static ssize_t kcs_bmc_write(struct file *filp, const char __user *buf,
-			     size_t count, loff_t *ppos)
-{
-	struct kcs_bmc *kcs_bmc = to_kcs_bmc(filp);
-	ssize_t ret;
-
-	/* a minimum response size '3' : netfn + cmd + ccode */
-	if (count < 3 || count > KCS_MSG_BUFSIZ)
-		return -EINVAL;
-
-	mutex_lock(&kcs_bmc->mutex);
-
-	if (copy_from_user(kcs_bmc->kbuffer, buf, count)) {
-		ret = -EFAULT;
-		goto out_unlock;
-	}
-
-	spin_lock_irq(&kcs_bmc->lock);
-	if (kcs_bmc->phase == KCS_PHASE_WAIT_READ) {
-		kcs_bmc->phase = KCS_PHASE_READ;
-		kcs_bmc->data_out_idx = 1;
-		kcs_bmc->data_out_len = count;
-		memcpy(kcs_bmc->data_out, kcs_bmc->kbuffer, count);
-		kcs_bmc_write_data(kcs_bmc, kcs_bmc->data_out[0]);
-		ret = count;
-	} else {
-		ret = -EINVAL;
-	}
-	spin_unlock_irq(&kcs_bmc->lock);
-
-out_unlock:
-	mutex_unlock(&kcs_bmc->mutex);
-
-	return ret;
-}
-
-static long kcs_bmc_ioctl(struct file *filp, unsigned int cmd,
-			  unsigned long arg)
-{
-	struct kcs_bmc *kcs_bmc = to_kcs_bmc(filp);
-	long ret = 0;
-
-	spin_lock_irq(&kcs_bmc->lock);
-
-	switch (cmd) {
-	case IPMI_BMC_IOCTL_SET_SMS_ATN:
-		kcs_bmc_update_status(kcs_bmc, KCS_STATUS_SMS_ATN, KCS_STATUS_SMS_ATN);
-		break;
-
-	case IPMI_BMC_IOCTL_CLEAR_SMS_ATN:
-		kcs_bmc_update_status(kcs_bmc, KCS_STATUS_SMS_ATN, 0);
-		break;
-
-	case IPMI_BMC_IOCTL_FORCE_ABORT:
-		kcs_force_abort(kcs_bmc);
-		break;
-
-	default:
-		ret = -EINVAL;
-		break;
-	}
-
-	spin_unlock_irq(&kcs_bmc->lock);
-
-	return ret;
-}
-
-static int kcs_bmc_release(struct inode *inode, struct file *filp)
-{
-	struct kcs_bmc *kcs_bmc = to_kcs_bmc(filp);
-
-	spin_lock_irq(&kcs_bmc->lock);
-	kcs_bmc->running = 0;
-	kcs_force_abort(kcs_bmc);
-	spin_unlock_irq(&kcs_bmc->lock);
-
-	return 0;
-}
-
-static const struct file_operations kcs_bmc_fops = {
-	.owner          = THIS_MODULE,
-	.open           = kcs_bmc_open,
-	.read           = kcs_bmc_read,
-	.write          = kcs_bmc_write,
-	.release        = kcs_bmc_release,
-	.poll           = kcs_bmc_poll,
-	.unlocked_ioctl = kcs_bmc_ioctl,
-};
-
+struct kcs_bmc *kcs_bmc_ipmi_alloc(struct device *dev, int sizeof_priv, u32 channel);
 struct kcs_bmc *kcs_bmc_alloc(struct device *dev, int sizeof_priv, u32 channel)
 {
-	struct kcs_bmc *kcs_bmc;
-
-	kcs_bmc = devm_kzalloc(dev, sizeof(*kcs_bmc) + sizeof_priv, GFP_KERNEL);
-	if (!kcs_bmc)
-		return NULL;
-
-	spin_lock_init(&kcs_bmc->lock);
-	kcs_bmc->channel = channel;
-
-	mutex_init(&kcs_bmc->mutex);
-	init_waitqueue_head(&kcs_bmc->queue);
-
-	kcs_bmc->data_in = devm_kmalloc(dev, KCS_MSG_BUFSIZ, GFP_KERNEL);
-	kcs_bmc->data_out = devm_kmalloc(dev, KCS_MSG_BUFSIZ, GFP_KERNEL);
-	kcs_bmc->kbuffer = devm_kmalloc(dev, KCS_MSG_BUFSIZ, GFP_KERNEL);
-
-	kcs_bmc->miscdev.minor = MISC_DYNAMIC_MINOR;
-	kcs_bmc->miscdev.name = devm_kasprintf(dev, GFP_KERNEL, "%s%u",
-					       DEVICE_NAME, channel);
-	if (!kcs_bmc->data_in || !kcs_bmc->data_out || !kcs_bmc->kbuffer ||
-	    !kcs_bmc->miscdev.name)
-		return NULL;
-	kcs_bmc->miscdev.fops = &kcs_bmc_fops;
-
-	return kcs_bmc;
+	return kcs_bmc_ipmi_alloc(dev, sizeof_priv, channel);
 }
 EXPORT_SYMBOL(kcs_bmc_alloc);
 
diff --git a/drivers/char/ipmi/kcs_bmc.h b/drivers/char/ipmi/kcs_bmc.h
index 970f53892f2d..febea0c8deb4 100644
--- a/drivers/char/ipmi/kcs_bmc.h
+++ b/drivers/char/ipmi/kcs_bmc.h
@@ -104,6 +104,12 @@ static inline void *kcs_bmc_priv(struct kcs_bmc *kcs_bmc)
 }
 
 int kcs_bmc_handle_event(struct kcs_bmc *kcs_bmc);
-struct kcs_bmc *kcs_bmc_alloc(struct device *dev, int sizeof_priv,
-					u32 channel);
+struct kcs_bmc *kcs_bmc_alloc(struct device *dev, int sizeof_priv, u32 channel);
+
+u8 kcs_bmc_read_data(struct kcs_bmc *kcs_bmc);
+void kcs_bmc_write_data(struct kcs_bmc *kcs_bmc, u8 data);
+u8 kcs_bmc_read_status(struct kcs_bmc *kcs_bmc);
+void kcs_bmc_write_status(struct kcs_bmc *kcs_bmc, u8 data);
+void kcs_bmc_update_status(struct kcs_bmc *kcs_bmc, u8 mask, u8 val);
+
 #endif /* __KCS_BMC_H__ */
diff --git a/drivers/char/ipmi/kcs_bmc_cdev_ipmi.c b/drivers/char/ipmi/kcs_bmc_cdev_ipmi.c
new file mode 100644
index 000000000000..82c77994e481
--- /dev/null
+++ b/drivers/char/ipmi/kcs_bmc_cdev_ipmi.c
@@ -0,0 +1,428 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2015-2018, Intel Corporation.
+ */
+
+#define pr_fmt(fmt) "kcs-bmc: " fmt
+
+#include <linux/errno.h>
+#include <linux/io.h>
+#include <linux/ipmi_bmc.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/poll.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+
+#include "kcs_bmc.h"
+
+#define DEVICE_NAME "ipmi-kcs"
+
+#define KCS_MSG_BUFSIZ    1000
+
+#define KCS_ZERO_DATA     0
+
+
+/* IPMI 2.0 - Table 9-1, KCS Interface Status Register Bits */
+#define KCS_STATUS_STATE(state) (state << 6)
+#define KCS_STATUS_STATE_MASK   GENMASK(7, 6)
+#define KCS_STATUS_CMD_DAT      BIT(3)
+#define KCS_STATUS_SMS_ATN      BIT(2)
+#define KCS_STATUS_IBF          BIT(1)
+#define KCS_STATUS_OBF          BIT(0)
+
+/* IPMI 2.0 - Table 9-2, KCS Interface State Bits */
+enum kcs_states {
+	IDLE_STATE  = 0,
+	READ_STATE  = 1,
+	WRITE_STATE = 2,
+	ERROR_STATE = 3,
+};
+
+/* IPMI 2.0 - Table 9-3, KCS Interface Control Codes */
+#define KCS_CMD_GET_STATUS_ABORT  0x60
+#define KCS_CMD_WRITE_START       0x61
+#define KCS_CMD_WRITE_END         0x62
+#define KCS_CMD_READ_BYTE         0x68
+
+static inline void set_state(struct kcs_bmc *kcs_bmc, u8 state)
+{
+	kcs_bmc_update_status(kcs_bmc, KCS_STATUS_STATE_MASK,
+					KCS_STATUS_STATE(state));
+}
+
+static void kcs_bmc_ipmi_force_abort(struct kcs_bmc *kcs_bmc)
+{
+	set_state(kcs_bmc, ERROR_STATE);
+	kcs_bmc_read_data(kcs_bmc);
+	kcs_bmc_write_data(kcs_bmc, KCS_ZERO_DATA);
+
+	kcs_bmc->phase = KCS_PHASE_ERROR;
+	kcs_bmc->data_in_avail = false;
+	kcs_bmc->data_in_idx = 0;
+}
+
+static void kcs_bmc_ipmi_handle_data(struct kcs_bmc *kcs_bmc)
+{
+	u8 data;
+
+	switch (kcs_bmc->phase) {
+	case KCS_PHASE_WRITE_START:
+		kcs_bmc->phase = KCS_PHASE_WRITE_DATA;
+		fallthrough;
+
+	case KCS_PHASE_WRITE_DATA:
+		if (kcs_bmc->data_in_idx < KCS_MSG_BUFSIZ) {
+			set_state(kcs_bmc, WRITE_STATE);
+			kcs_bmc_write_data(kcs_bmc, KCS_ZERO_DATA);
+			kcs_bmc->data_in[kcs_bmc->data_in_idx++] =
+						kcs_bmc_read_data(kcs_bmc);
+		} else {
+			kcs_bmc_ipmi_force_abort(kcs_bmc);
+			kcs_bmc->error = KCS_LENGTH_ERROR;
+		}
+		break;
+
+	case KCS_PHASE_WRITE_END_CMD:
+		if (kcs_bmc->data_in_idx < KCS_MSG_BUFSIZ) {
+			set_state(kcs_bmc, READ_STATE);
+			kcs_bmc->data_in[kcs_bmc->data_in_idx++] =
+						kcs_bmc_read_data(kcs_bmc);
+			kcs_bmc->phase = KCS_PHASE_WRITE_DONE;
+			kcs_bmc->data_in_avail = true;
+			wake_up_interruptible(&kcs_bmc->queue);
+		} else {
+			kcs_bmc_ipmi_force_abort(kcs_bmc);
+			kcs_bmc->error = KCS_LENGTH_ERROR;
+		}
+		break;
+
+	case KCS_PHASE_READ:
+		if (kcs_bmc->data_out_idx == kcs_bmc->data_out_len)
+			set_state(kcs_bmc, IDLE_STATE);
+
+		data = kcs_bmc_read_data(kcs_bmc);
+		if (data != KCS_CMD_READ_BYTE) {
+			set_state(kcs_bmc, ERROR_STATE);
+			kcs_bmc_write_data(kcs_bmc, KCS_ZERO_DATA);
+			break;
+		}
+
+		if (kcs_bmc->data_out_idx == kcs_bmc->data_out_len) {
+			kcs_bmc_write_data(kcs_bmc, KCS_ZERO_DATA);
+			kcs_bmc->phase = KCS_PHASE_IDLE;
+			break;
+		}
+
+		kcs_bmc_write_data(kcs_bmc,
+			kcs_bmc->data_out[kcs_bmc->data_out_idx++]);
+		break;
+
+	case KCS_PHASE_ABORT_ERROR1:
+		set_state(kcs_bmc, READ_STATE);
+		kcs_bmc_read_data(kcs_bmc);
+		kcs_bmc_write_data(kcs_bmc, kcs_bmc->error);
+		kcs_bmc->phase = KCS_PHASE_ABORT_ERROR2;
+		break;
+
+	case KCS_PHASE_ABORT_ERROR2:
+		set_state(kcs_bmc, IDLE_STATE);
+		kcs_bmc_read_data(kcs_bmc);
+		kcs_bmc_write_data(kcs_bmc, KCS_ZERO_DATA);
+		kcs_bmc->phase = KCS_PHASE_IDLE;
+		break;
+
+	default:
+		kcs_bmc_ipmi_force_abort(kcs_bmc);
+		break;
+	}
+}
+
+static void kcs_bmc_ipmi_handle_cmd(struct kcs_bmc *kcs_bmc)
+{
+	u8 cmd;
+
+	set_state(kcs_bmc, WRITE_STATE);
+	kcs_bmc_write_data(kcs_bmc, KCS_ZERO_DATA);
+
+	cmd = kcs_bmc_read_data(kcs_bmc);
+	switch (cmd) {
+	case KCS_CMD_WRITE_START:
+		kcs_bmc->phase = KCS_PHASE_WRITE_START;
+		kcs_bmc->error = KCS_NO_ERROR;
+		kcs_bmc->data_in_avail = false;
+		kcs_bmc->data_in_idx = 0;
+		break;
+
+	case KCS_CMD_WRITE_END:
+		if (kcs_bmc->phase != KCS_PHASE_WRITE_DATA) {
+			kcs_bmc_ipmi_force_abort(kcs_bmc);
+			break;
+		}
+
+		kcs_bmc->phase = KCS_PHASE_WRITE_END_CMD;
+		break;
+
+	case KCS_CMD_GET_STATUS_ABORT:
+		if (kcs_bmc->error == KCS_NO_ERROR)
+			kcs_bmc->error = KCS_ABORTED_BY_COMMAND;
+
+		kcs_bmc->phase = KCS_PHASE_ABORT_ERROR1;
+		kcs_bmc->data_in_avail = false;
+		kcs_bmc->data_in_idx = 0;
+		break;
+
+	default:
+		kcs_bmc_ipmi_force_abort(kcs_bmc);
+		kcs_bmc->error = KCS_ILLEGAL_CONTROL_CODE;
+		break;
+	}
+}
+
+int kcs_bmc_ipmi_event(struct kcs_bmc *kcs_bmc);
+int kcs_bmc_ipmi_event(struct kcs_bmc *kcs_bmc)
+{
+	unsigned long flags;
+	int ret = -ENODATA;
+	u8 status;
+
+	spin_lock_irqsave(&kcs_bmc->lock, flags);
+
+	status = kcs_bmc_read_status(kcs_bmc);
+	if (status & KCS_STATUS_IBF) {
+		if (!kcs_bmc->running)
+			kcs_bmc_ipmi_force_abort(kcs_bmc);
+		else if (status & KCS_STATUS_CMD_DAT)
+			kcs_bmc_ipmi_handle_cmd(kcs_bmc);
+		else
+			kcs_bmc_ipmi_handle_data(kcs_bmc);
+
+		ret = 0;
+	}
+
+	spin_unlock_irqrestore(&kcs_bmc->lock, flags);
+
+	return ret;
+}
+EXPORT_SYMBOL(kcs_bmc_ipmi_event);
+
+static inline struct kcs_bmc *to_kcs_bmc(struct file *filp)
+{
+	return container_of(filp->private_data, struct kcs_bmc, miscdev);
+}
+
+static int kcs_bmc_ipmi_open(struct inode *inode, struct file *filp)
+{
+	struct kcs_bmc *kcs_bmc = to_kcs_bmc(filp);
+	int ret = 0;
+
+	spin_lock_irq(&kcs_bmc->lock);
+	if (!kcs_bmc->running)
+		kcs_bmc->running = 1;
+	else
+		ret = -EBUSY;
+	spin_unlock_irq(&kcs_bmc->lock);
+
+	return ret;
+}
+
+static __poll_t kcs_bmc_ipmi_poll(struct file *filp, poll_table *wait)
+{
+	struct kcs_bmc *kcs_bmc = to_kcs_bmc(filp);
+	__poll_t mask = 0;
+
+	poll_wait(filp, &kcs_bmc->queue, wait);
+
+	spin_lock_irq(&kcs_bmc->lock);
+	if (kcs_bmc->data_in_avail)
+		mask |= EPOLLIN;
+	spin_unlock_irq(&kcs_bmc->lock);
+
+	return mask;
+}
+
+static ssize_t kcs_bmc_ipmi_read(struct file *filp, char __user *buf,
+			    size_t count, loff_t *ppos)
+{
+	struct kcs_bmc *kcs_bmc = to_kcs_bmc(filp);
+	bool data_avail;
+	size_t data_len;
+	ssize_t ret;
+
+	if (!(filp->f_flags & O_NONBLOCK))
+		wait_event_interruptible(kcs_bmc->queue,
+					 kcs_bmc->data_in_avail);
+
+	mutex_lock(&kcs_bmc->mutex);
+
+	spin_lock_irq(&kcs_bmc->lock);
+	data_avail = kcs_bmc->data_in_avail;
+	if (data_avail) {
+		data_len = kcs_bmc->data_in_idx;
+		memcpy(kcs_bmc->kbuffer, kcs_bmc->data_in, data_len);
+	}
+	spin_unlock_irq(&kcs_bmc->lock);
+
+	if (!data_avail) {
+		ret = -EAGAIN;
+		goto out_unlock;
+	}
+
+	if (count < data_len) {
+		pr_err("channel=%u with too large data : %zu\n",
+			kcs_bmc->channel, data_len);
+
+		spin_lock_irq(&kcs_bmc->lock);
+		kcs_bmc_ipmi_force_abort(kcs_bmc);
+		spin_unlock_irq(&kcs_bmc->lock);
+
+		ret = -EOVERFLOW;
+		goto out_unlock;
+	}
+
+	if (copy_to_user(buf, kcs_bmc->kbuffer, data_len)) {
+		ret = -EFAULT;
+		goto out_unlock;
+	}
+
+	ret = data_len;
+
+	spin_lock_irq(&kcs_bmc->lock);
+	if (kcs_bmc->phase == KCS_PHASE_WRITE_DONE) {
+		kcs_bmc->phase = KCS_PHASE_WAIT_READ;
+		kcs_bmc->data_in_avail = false;
+		kcs_bmc->data_in_idx = 0;
+	} else {
+		ret = -EAGAIN;
+	}
+	spin_unlock_irq(&kcs_bmc->lock);
+
+out_unlock:
+	mutex_unlock(&kcs_bmc->mutex);
+
+	return ret;
+}
+
+static ssize_t kcs_bmc_ipmi_write(struct file *filp, const char __user *buf,
+			     size_t count, loff_t *ppos)
+{
+	struct kcs_bmc *kcs_bmc = to_kcs_bmc(filp);
+	ssize_t ret;
+
+	/* a minimum response size '3' : netfn + cmd + ccode */
+	if (count < 3 || count > KCS_MSG_BUFSIZ)
+		return -EINVAL;
+
+	mutex_lock(&kcs_bmc->mutex);
+
+	if (copy_from_user(kcs_bmc->kbuffer, buf, count)) {
+		ret = -EFAULT;
+		goto out_unlock;
+	}
+
+	spin_lock_irq(&kcs_bmc->lock);
+	if (kcs_bmc->phase == KCS_PHASE_WAIT_READ) {
+		kcs_bmc->phase = KCS_PHASE_READ;
+		kcs_bmc->data_out_idx = 1;
+		kcs_bmc->data_out_len = count;
+		memcpy(kcs_bmc->data_out, kcs_bmc->kbuffer, count);
+		kcs_bmc_write_data(kcs_bmc, kcs_bmc->data_out[0]);
+		ret = count;
+	} else {
+		ret = -EINVAL;
+	}
+	spin_unlock_irq(&kcs_bmc->lock);
+
+out_unlock:
+	mutex_unlock(&kcs_bmc->mutex);
+
+	return ret;
+}
+
+static long kcs_bmc_ipmi_ioctl(struct file *filp, unsigned int cmd,
+			  unsigned long arg)
+{
+	struct kcs_bmc *kcs_bmc = to_kcs_bmc(filp);
+	long ret = 0;
+
+	spin_lock_irq(&kcs_bmc->lock);
+
+	switch (cmd) {
+	case IPMI_BMC_IOCTL_SET_SMS_ATN:
+		kcs_bmc_update_status(kcs_bmc, KCS_STATUS_SMS_ATN, KCS_STATUS_SMS_ATN);
+		break;
+
+	case IPMI_BMC_IOCTL_CLEAR_SMS_ATN:
+		kcs_bmc_update_status(kcs_bmc, KCS_STATUS_SMS_ATN, 0);
+		break;
+
+	case IPMI_BMC_IOCTL_FORCE_ABORT:
+		kcs_bmc_ipmi_force_abort(kcs_bmc);
+		break;
+
+	default:
+		ret = -EINVAL;
+		break;
+	}
+
+	spin_unlock_irq(&kcs_bmc->lock);
+
+	return ret;
+}
+
+static int kcs_bmc_ipmi_release(struct inode *inode, struct file *filp)
+{
+	struct kcs_bmc *kcs_bmc = to_kcs_bmc(filp);
+
+	spin_lock_irq(&kcs_bmc->lock);
+	kcs_bmc->running = 0;
+	kcs_bmc_ipmi_force_abort(kcs_bmc);
+	spin_unlock_irq(&kcs_bmc->lock);
+
+	return 0;
+}
+
+static const struct file_operations kcs_bmc_fops = {
+	.owner          = THIS_MODULE,
+	.open           = kcs_bmc_ipmi_open,
+	.read           = kcs_bmc_ipmi_read,
+	.write          = kcs_bmc_ipmi_write,
+	.release        = kcs_bmc_ipmi_release,
+	.poll           = kcs_bmc_ipmi_poll,
+	.unlocked_ioctl = kcs_bmc_ipmi_ioctl,
+};
+
+struct kcs_bmc *kcs_bmc_ipmi_alloc(struct device *dev, int sizeof_priv, u32 channel);
+struct kcs_bmc *kcs_bmc_ipmi_alloc(struct device *dev, int sizeof_priv, u32 channel)
+{
+	struct kcs_bmc *kcs_bmc;
+
+	kcs_bmc = devm_kzalloc(dev, sizeof(*kcs_bmc) + sizeof_priv, GFP_KERNEL);
+	if (!kcs_bmc)
+		return NULL;
+
+	spin_lock_init(&kcs_bmc->lock);
+	kcs_bmc->channel = channel;
+
+	mutex_init(&kcs_bmc->mutex);
+	init_waitqueue_head(&kcs_bmc->queue);
+
+	kcs_bmc->data_in = devm_kmalloc(dev, KCS_MSG_BUFSIZ, GFP_KERNEL);
+	kcs_bmc->data_out = devm_kmalloc(dev, KCS_MSG_BUFSIZ, GFP_KERNEL);
+	kcs_bmc->kbuffer = devm_kmalloc(dev, KCS_MSG_BUFSIZ, GFP_KERNEL);
+
+	kcs_bmc->miscdev.minor = MISC_DYNAMIC_MINOR;
+	kcs_bmc->miscdev.name = devm_kasprintf(dev, GFP_KERNEL, "%s%u",
+					       DEVICE_NAME, channel);
+	if (!kcs_bmc->data_in || !kcs_bmc->data_out || !kcs_bmc->kbuffer ||
+	    !kcs_bmc->miscdev.name)
+		return NULL;
+	kcs_bmc->miscdev.fops = &kcs_bmc_fops;
+
+	return kcs_bmc;
+}
+EXPORT_SYMBOL(kcs_bmc_ipmi_alloc);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Haiyue Wang <haiyue.wang@linux.intel.com>");
+MODULE_DESCRIPTION("KCS BMC to handle the IPMI request from system software");
-- 
2.30.2


^ permalink raw reply related	[flat|nested] 23+ messages in thread

* [PATCH v4 05/16] ipmi: kcs_bmc: Turn the driver data-structures inside-out
  2021-06-08 10:47 [PATCH v4 00/16] ipmi: Allow raw access to KCS devices Andrew Jeffery
                   ` (3 preceding siblings ...)
  2021-06-08 10:47 ` [PATCH v4 04/16] ipmi: kcs_bmc: Split out kcs_bmc_cdev_ipmi Andrew Jeffery
@ 2021-06-08 10:47 ` Andrew Jeffery
  2021-06-08 10:47 ` [PATCH v4 06/16] ipmi: kcs_bmc: Split headers into device and client Andrew Jeffery
                   ` (11 subsequent siblings)
  16 siblings, 0 replies; 23+ messages in thread
From: Andrew Jeffery @ 2021-06-08 10:47 UTC (permalink / raw)
  To: openipmi-developer, openbmc, minyard
  Cc: devicetree, tmaimon77, linux-aspeed, avifishman70, venture,
	linux-kernel, tali.perry1, robh+dt, chiawei_wang,
	linux-arm-kernel, benjaminfair, arnd, zweiss, joel, KWLIU

Make the KCS device drivers responsible for allocating their own memory.

Until now the private data for the device driver was allocated internal
to the private data for the chardev interface. This coupling required
the slightly awkward API of passing through the struct size for the
driver private data to the chardev constructor, and then retrieving a
pointer to the driver private data from the allocated chardev memory.

In addition to being awkward, the arrangement prevents the
implementation of alternative userspace interfaces as the device driver
private data is not independent.

Peel a layer off the onion and turn the data-structures inside out by
exploiting container_of() and embedding `struct kcs_device` in the
driver private data.

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Reviewed-by: Zev Weiss <zweiss@equinix.com>
---
 drivers/char/ipmi/kcs_bmc.c           | 17 ++++++--
 drivers/char/ipmi/kcs_bmc.h           | 12 ++----
 drivers/char/ipmi/kcs_bmc_aspeed.c    | 54 +++++++++++++-----------
 drivers/char/ipmi/kcs_bmc_cdev_ipmi.c | 60 ++++++++++++++++++---------
 drivers/char/ipmi/kcs_bmc_npcm7xx.c   | 34 +++++++++------
 5 files changed, 110 insertions(+), 67 deletions(-)

diff --git a/drivers/char/ipmi/kcs_bmc.c b/drivers/char/ipmi/kcs_bmc.c
index ef5c48ffe74a..07bb6747f29a 100644
--- a/drivers/char/ipmi/kcs_bmc.c
+++ b/drivers/char/ipmi/kcs_bmc.c
@@ -44,12 +44,21 @@ int kcs_bmc_handle_event(struct kcs_bmc *kcs_bmc)
 }
 EXPORT_SYMBOL(kcs_bmc_handle_event);
 
-struct kcs_bmc *kcs_bmc_ipmi_alloc(struct device *dev, int sizeof_priv, u32 channel);
-struct kcs_bmc *kcs_bmc_alloc(struct device *dev, int sizeof_priv, u32 channel)
+int kcs_bmc_ipmi_add_device(struct kcs_bmc *kcs_bmc);
+int kcs_bmc_add_device(struct kcs_bmc *kcs_bmc)
 {
-	return kcs_bmc_ipmi_alloc(dev, sizeof_priv, channel);
+	return kcs_bmc_ipmi_add_device(kcs_bmc);
 }
-EXPORT_SYMBOL(kcs_bmc_alloc);
+EXPORT_SYMBOL(kcs_bmc_add_device);
+
+int kcs_bmc_ipmi_remove_device(struct kcs_bmc *kcs_bmc);
+void kcs_bmc_remove_device(struct kcs_bmc *kcs_bmc)
+{
+	if (kcs_bmc_ipmi_remove_device(kcs_bmc))
+		pr_warn("Failed to remove device for KCS channel %d\n",
+			kcs_bmc->channel);
+}
+EXPORT_SYMBOL(kcs_bmc_remove_device);
 
 MODULE_LICENSE("GPL v2");
 MODULE_AUTHOR("Haiyue Wang <haiyue.wang@linux.intel.com>");
diff --git a/drivers/char/ipmi/kcs_bmc.h b/drivers/char/ipmi/kcs_bmc.h
index febea0c8deb4..f3ed89e7da98 100644
--- a/drivers/char/ipmi/kcs_bmc.h
+++ b/drivers/char/ipmi/kcs_bmc.h
@@ -67,6 +67,8 @@ struct kcs_ioreg {
 };
 
 struct kcs_bmc {
+	struct device *dev;
+
 	spinlock_t lock;
 
 	u32 channel;
@@ -94,17 +96,11 @@ struct kcs_bmc {
 	u8 *kbuffer;
 
 	struct miscdevice miscdev;
-
-	unsigned long priv[];
 };
 
-static inline void *kcs_bmc_priv(struct kcs_bmc *kcs_bmc)
-{
-	return kcs_bmc->priv;
-}
-
 int kcs_bmc_handle_event(struct kcs_bmc *kcs_bmc);
-struct kcs_bmc *kcs_bmc_alloc(struct device *dev, int sizeof_priv, u32 channel);
+int kcs_bmc_add_device(struct kcs_bmc *kcs_bmc);
+void kcs_bmc_remove_device(struct kcs_bmc *kcs_bmc);
 
 u8 kcs_bmc_read_data(struct kcs_bmc *kcs_bmc);
 void kcs_bmc_write_data(struct kcs_bmc *kcs_bmc, u8 data);
diff --git a/drivers/char/ipmi/kcs_bmc_aspeed.c b/drivers/char/ipmi/kcs_bmc_aspeed.c
index 01ebb9da3d49..b07cbc423dd5 100644
--- a/drivers/char/ipmi/kcs_bmc_aspeed.c
+++ b/drivers/char/ipmi/kcs_bmc_aspeed.c
@@ -61,6 +61,8 @@
 #define LPC_STR4             0x11C
 
 struct aspeed_kcs_bmc {
+	struct kcs_bmc kcs_bmc;
+
 	struct regmap *map;
 };
 
@@ -69,9 +71,14 @@ struct aspeed_kcs_of_ops {
 	int (*get_io_address)(struct platform_device *pdev);
 };
 
+static inline struct aspeed_kcs_bmc *to_aspeed_kcs_bmc(struct kcs_bmc *kcs_bmc)
+{
+	return container_of(kcs_bmc, struct aspeed_kcs_bmc, kcs_bmc);
+}
+
 static u8 aspeed_kcs_inb(struct kcs_bmc *kcs_bmc, u32 reg)
 {
-	struct aspeed_kcs_bmc *priv = kcs_bmc_priv(kcs_bmc);
+	struct aspeed_kcs_bmc *priv = to_aspeed_kcs_bmc(kcs_bmc);
 	u32 val = 0;
 	int rc;
 
@@ -83,7 +90,7 @@ static u8 aspeed_kcs_inb(struct kcs_bmc *kcs_bmc, u32 reg)
 
 static void aspeed_kcs_outb(struct kcs_bmc *kcs_bmc, u32 reg, u8 data)
 {
-	struct aspeed_kcs_bmc *priv = kcs_bmc_priv(kcs_bmc);
+	struct aspeed_kcs_bmc *priv = to_aspeed_kcs_bmc(kcs_bmc);
 	int rc;
 
 	rc = regmap_write(priv->map, reg, data);
@@ -92,7 +99,7 @@ static void aspeed_kcs_outb(struct kcs_bmc *kcs_bmc, u32 reg, u8 data)
 
 static void aspeed_kcs_updateb(struct kcs_bmc *kcs_bmc, u32 reg, u8 mask, u8 val)
 {
-	struct aspeed_kcs_bmc *priv = kcs_bmc_priv(kcs_bmc);
+	struct aspeed_kcs_bmc *priv = to_aspeed_kcs_bmc(kcs_bmc);
 	int rc;
 
 	rc = regmap_update_bits(priv->map, reg, mask, val);
@@ -114,7 +121,7 @@ static void aspeed_kcs_updateb(struct kcs_bmc *kcs_bmc, u32 reg, u8 mask, u8 val
  */
 static void aspeed_kcs_set_address(struct kcs_bmc *kcs_bmc, u16 addr)
 {
-	struct aspeed_kcs_bmc *priv = kcs_bmc_priv(kcs_bmc);
+	struct aspeed_kcs_bmc *priv = to_aspeed_kcs_bmc(kcs_bmc);
 
 	switch (kcs_bmc->channel) {
 	case 1:
@@ -148,7 +155,7 @@ static void aspeed_kcs_set_address(struct kcs_bmc *kcs_bmc, u16 addr)
 
 static void aspeed_kcs_enable_channel(struct kcs_bmc *kcs_bmc, bool enable)
 {
-	struct aspeed_kcs_bmc *priv = kcs_bmc_priv(kcs_bmc);
+	struct aspeed_kcs_bmc *priv = to_aspeed_kcs_bmc(kcs_bmc);
 
 	switch (kcs_bmc->channel) {
 	case 1:
@@ -325,17 +332,16 @@ static int aspeed_kcs_of_v2_get_io_address(struct platform_device *pdev)
 static int aspeed_kcs_probe(struct platform_device *pdev)
 {
 	const struct aspeed_kcs_of_ops *ops;
-	struct device *dev = &pdev->dev;
 	struct aspeed_kcs_bmc *priv;
 	struct kcs_bmc *kcs_bmc;
 	struct device_node *np;
 	int rc, channel, addr;
 
-	np = dev->of_node->parent;
+	np = pdev->dev.of_node->parent;
 	if (!of_device_is_compatible(np, "aspeed,ast2400-lpc-v2") &&
 	    !of_device_is_compatible(np, "aspeed,ast2500-lpc-v2") &&
 	    !of_device_is_compatible(np, "aspeed,ast2600-lpc-v2")) {
-		dev_err(dev, "unsupported LPC device binding\n");
+		dev_err(&pdev->dev, "unsupported LPC device binding\n");
 		return -ENODEV;
 	}
 	ops = of_device_get_match_data(&pdev->dev);
@@ -346,20 +352,22 @@ static int aspeed_kcs_probe(struct platform_device *pdev)
 	if (channel < 0)
 		return channel;
 
-	kcs_bmc = kcs_bmc_alloc(&pdev->dev, sizeof(struct aspeed_kcs_bmc), channel);
-	if (!kcs_bmc)
+	addr = ops->get_io_address(pdev);
+	if (addr < 0)
+		return addr;
+
+	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
 		return -ENOMEM;
 
+	kcs_bmc = &priv->kcs_bmc;
+	kcs_bmc->dev = &pdev->dev;
+	kcs_bmc->channel = channel;
 	kcs_bmc->ioreg = ast_kcs_bmc_ioregs[channel - 1];
 	kcs_bmc->io_inputb = aspeed_kcs_inb;
 	kcs_bmc->io_outputb = aspeed_kcs_outb;
 	kcs_bmc->io_updateb = aspeed_kcs_updateb;
 
-	addr = ops->get_io_address(pdev);
-	if (addr < 0)
-		return addr;
-
-	priv = kcs_bmc_priv(kcs_bmc);
 	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");
@@ -372,29 +380,27 @@ static int aspeed_kcs_probe(struct platform_device *pdev)
 	if (rc)
 		return rc;
 
-	dev_set_drvdata(dev, kcs_bmc);
+	platform_set_drvdata(pdev, priv);
 
 	aspeed_kcs_enable_channel(kcs_bmc, true);
 
-	rc = misc_register(&kcs_bmc->miscdev);
+	rc = kcs_bmc_add_device(&priv->kcs_bmc);
 	if (rc) {
-		dev_err(dev, "Unable to register device\n");
+		dev_warn(&pdev->dev, "Failed to register channel %d: %d\n", kcs_bmc->channel, rc);
 		return rc;
 	}
 
-	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);
+	dev_info(&pdev->dev, "Initialised channel %d at 0x%x\n", kcs_bmc->channel, addr);
 
 	return 0;
 }
 
 static int aspeed_kcs_remove(struct platform_device *pdev)
 {
-	struct kcs_bmc *kcs_bmc = dev_get_drvdata(&pdev->dev);
+	struct aspeed_kcs_bmc *priv = platform_get_drvdata(pdev);
+	struct kcs_bmc *kcs_bmc = &priv->kcs_bmc;
 
-	misc_deregister(&kcs_bmc->miscdev);
+	kcs_bmc_remove_device(kcs_bmc);
 
 	return 0;
 }
diff --git a/drivers/char/ipmi/kcs_bmc_cdev_ipmi.c b/drivers/char/ipmi/kcs_bmc_cdev_ipmi.c
index 82c77994e481..5060643bf530 100644
--- a/drivers/char/ipmi/kcs_bmc_cdev_ipmi.c
+++ b/drivers/char/ipmi/kcs_bmc_cdev_ipmi.c
@@ -382,7 +382,7 @@ static int kcs_bmc_ipmi_release(struct inode *inode, struct file *filp)
 	return 0;
 }
 
-static const struct file_operations kcs_bmc_fops = {
+static const struct file_operations kcs_bmc_ipmi_fops = {
 	.owner          = THIS_MODULE,
 	.open           = kcs_bmc_ipmi_open,
 	.read           = kcs_bmc_ipmi_read,
@@ -392,36 +392,58 @@ static const struct file_operations kcs_bmc_fops = {
 	.unlocked_ioctl = kcs_bmc_ipmi_ioctl,
 };
 
-struct kcs_bmc *kcs_bmc_ipmi_alloc(struct device *dev, int sizeof_priv, u32 channel);
-struct kcs_bmc *kcs_bmc_ipmi_alloc(struct device *dev, int sizeof_priv, u32 channel)
+int kcs_bmc_ipmi_add_device(struct kcs_bmc *kcs_bmc);
+int kcs_bmc_ipmi_add_device(struct kcs_bmc *kcs_bmc)
 {
-	struct kcs_bmc *kcs_bmc;
-
-	kcs_bmc = devm_kzalloc(dev, sizeof(*kcs_bmc) + sizeof_priv, GFP_KERNEL);
-	if (!kcs_bmc)
-		return NULL;
+	int rc;
 
 	spin_lock_init(&kcs_bmc->lock);
-	kcs_bmc->channel = channel;
-
 	mutex_init(&kcs_bmc->mutex);
 	init_waitqueue_head(&kcs_bmc->queue);
 
-	kcs_bmc->data_in = devm_kmalloc(dev, KCS_MSG_BUFSIZ, GFP_KERNEL);
-	kcs_bmc->data_out = devm_kmalloc(dev, KCS_MSG_BUFSIZ, GFP_KERNEL);
-	kcs_bmc->kbuffer = devm_kmalloc(dev, KCS_MSG_BUFSIZ, GFP_KERNEL);
+	kcs_bmc->data_in = devm_kmalloc(kcs_bmc->dev, KCS_MSG_BUFSIZ, GFP_KERNEL);
+	kcs_bmc->data_out = devm_kmalloc(kcs_bmc->dev, KCS_MSG_BUFSIZ, GFP_KERNEL);
+	kcs_bmc->kbuffer = devm_kmalloc(kcs_bmc->dev, KCS_MSG_BUFSIZ, GFP_KERNEL);
 
 	kcs_bmc->miscdev.minor = MISC_DYNAMIC_MINOR;
-	kcs_bmc->miscdev.name = devm_kasprintf(dev, GFP_KERNEL, "%s%u",
-					       DEVICE_NAME, channel);
+	kcs_bmc->miscdev.name = devm_kasprintf(kcs_bmc->dev, GFP_KERNEL, "%s%u",
+					       DEVICE_NAME, kcs_bmc->channel);
 	if (!kcs_bmc->data_in || !kcs_bmc->data_out || !kcs_bmc->kbuffer ||
 	    !kcs_bmc->miscdev.name)
-		return NULL;
-	kcs_bmc->miscdev.fops = &kcs_bmc_fops;
+		return -ENOMEM;
 
-	return kcs_bmc;
+	kcs_bmc->miscdev.fops = &kcs_bmc_ipmi_fops;
+
+	rc = misc_register(&kcs_bmc->miscdev);
+	if (rc) {
+		dev_err(kcs_bmc->dev, "Unable to register device: %d\n", rc);
+		return rc;
+	}
+
+	dev_info(kcs_bmc->dev, "Initialised IPMI client for channel %d", kcs_bmc->channel);
+
+	return 0;
+}
+EXPORT_SYMBOL(kcs_bmc_ipmi_add_device);
+
+int kcs_bmc_ipmi_remove_device(struct kcs_bmc *kcs_bmc);
+int kcs_bmc_ipmi_remove_device(struct kcs_bmc *kcs_bmc)
+{
+	misc_deregister(&kcs_bmc->miscdev);
+
+	spin_lock_irq(&kcs_bmc->lock);
+	kcs_bmc->running = 0;
+	kcs_bmc_ipmi_force_abort(kcs_bmc);
+	spin_unlock_irq(&kcs_bmc->lock);
+
+	devm_kfree(kcs_bmc->dev, kcs_bmc->kbuffer);
+	devm_kfree(kcs_bmc->dev, kcs_bmc->data_out);
+	devm_kfree(kcs_bmc->dev, kcs_bmc->data_in);
+	devm_kfree(kcs_bmc->dev, kcs_bmc);
+
+	return 0;
 }
-EXPORT_SYMBOL(kcs_bmc_ipmi_alloc);
+EXPORT_SYMBOL(kcs_bmc_ipmi_remove_device);
 
 MODULE_LICENSE("GPL v2");
 MODULE_AUTHOR("Haiyue Wang <haiyue.wang@linux.intel.com>");
diff --git a/drivers/char/ipmi/kcs_bmc_npcm7xx.c b/drivers/char/ipmi/kcs_bmc_npcm7xx.c
index 1f44aadec9e8..e06250285113 100644
--- a/drivers/char/ipmi/kcs_bmc_npcm7xx.c
+++ b/drivers/char/ipmi/kcs_bmc_npcm7xx.c
@@ -65,6 +65,8 @@ struct npcm7xx_kcs_reg {
 };
 
 struct npcm7xx_kcs_bmc {
+	struct kcs_bmc kcs_bmc;
+
 	struct regmap *map;
 
 	const struct npcm7xx_kcs_reg *reg;
@@ -76,9 +78,14 @@ static const struct npcm7xx_kcs_reg npcm7xx_kcs_reg_tbl[KCS_CHANNEL_MAX] = {
 	{ .sts = KCS3ST, .dob = KCS3DO, .dib = KCS3DI, .ctl = KCS3CTL, .ie = KCS3IE },
 };
 
+static inline struct npcm7xx_kcs_bmc *to_npcm7xx_kcs_bmc(struct kcs_bmc *kcs_bmc)
+{
+	return container_of(kcs_bmc, struct npcm7xx_kcs_bmc, kcs_bmc);
+}
+
 static u8 npcm7xx_kcs_inb(struct kcs_bmc *kcs_bmc, u32 reg)
 {
-	struct npcm7xx_kcs_bmc *priv = kcs_bmc_priv(kcs_bmc);
+	struct npcm7xx_kcs_bmc *priv = to_npcm7xx_kcs_bmc(kcs_bmc);
 	u32 val = 0;
 	int rc;
 
@@ -90,7 +97,7 @@ static u8 npcm7xx_kcs_inb(struct kcs_bmc *kcs_bmc, u32 reg)
 
 static void npcm7xx_kcs_outb(struct kcs_bmc *kcs_bmc, u32 reg, u8 data)
 {
-	struct npcm7xx_kcs_bmc *priv = kcs_bmc_priv(kcs_bmc);
+	struct npcm7xx_kcs_bmc *priv = to_npcm7xx_kcs_bmc(kcs_bmc);
 	int rc;
 
 	rc = regmap_write(priv->map, reg, data);
@@ -99,7 +106,7 @@ static void npcm7xx_kcs_outb(struct kcs_bmc *kcs_bmc, u32 reg, u8 data)
 
 static void npcm7xx_kcs_updateb(struct kcs_bmc *kcs_bmc, u32 reg, u8 mask, u8 data)
 {
-	struct npcm7xx_kcs_bmc *priv = kcs_bmc_priv(kcs_bmc);
+	struct npcm7xx_kcs_bmc *priv = to_npcm7xx_kcs_bmc(kcs_bmc);
 	int rc;
 
 	rc = regmap_update_bits(priv->map, reg, mask, data);
@@ -108,7 +115,7 @@ static void npcm7xx_kcs_updateb(struct kcs_bmc *kcs_bmc, u32 reg, u8 mask, u8 da
 
 static void npcm7xx_kcs_enable_channel(struct kcs_bmc *kcs_bmc, bool enable)
 {
-	struct npcm7xx_kcs_bmc *priv = kcs_bmc_priv(kcs_bmc);
+	struct npcm7xx_kcs_bmc *priv = to_npcm7xx_kcs_bmc(kcs_bmc);
 
 	regmap_update_bits(priv->map, priv->reg->ctl, KCS_CTL_IBFIE,
 			   enable ? KCS_CTL_IBFIE : 0);
@@ -155,11 +162,10 @@ static int npcm7xx_kcs_probe(struct platform_device *pdev)
 		return -ENODEV;
 	}
 
-	kcs_bmc = kcs_bmc_alloc(dev, sizeof(*priv), chan);
-	if (!kcs_bmc)
+	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
 		return -ENOMEM;
 
-	priv = kcs_bmc_priv(kcs_bmc);
 	priv->map = syscon_node_to_regmap(dev->parent->of_node);
 	if (IS_ERR(priv->map)) {
 		dev_err(dev, "Couldn't get regmap\n");
@@ -167,6 +173,9 @@ static int npcm7xx_kcs_probe(struct platform_device *pdev)
 	}
 	priv->reg = &npcm7xx_kcs_reg_tbl[chan - 1];
 
+	kcs_bmc = &priv->kcs_bmc;
+	kcs_bmc->dev = &pdev->dev;
+	kcs_bmc->channel = chan;
 	kcs_bmc->ioreg.idr = priv->reg->dib;
 	kcs_bmc->ioreg.odr = priv->reg->dob;
 	kcs_bmc->ioreg.str = priv->reg->sts;
@@ -174,16 +183,16 @@ static int npcm7xx_kcs_probe(struct platform_device *pdev)
 	kcs_bmc->io_outputb = npcm7xx_kcs_outb;
 	kcs_bmc->io_updateb = npcm7xx_kcs_updateb;
 
-	dev_set_drvdata(dev, kcs_bmc);
+	platform_set_drvdata(pdev, priv);
 
 	npcm7xx_kcs_enable_channel(kcs_bmc, true);
 	rc = npcm7xx_kcs_config_irq(kcs_bmc, pdev);
 	if (rc)
 		return rc;
 
-	rc = misc_register(&kcs_bmc->miscdev);
+	rc = kcs_bmc_add_device(kcs_bmc);
 	if (rc) {
-		dev_err(dev, "Unable to register device\n");
+		dev_warn(&pdev->dev, "Failed to register channel %d: %d\n", kcs_bmc->channel, rc);
 		return rc;
 	}
 
@@ -196,9 +205,10 @@ static int npcm7xx_kcs_probe(struct platform_device *pdev)
 
 static int npcm7xx_kcs_remove(struct platform_device *pdev)
 {
-	struct kcs_bmc *kcs_bmc = dev_get_drvdata(&pdev->dev);
+	struct npcm7xx_kcs_bmc *priv = platform_get_drvdata(pdev);
+	struct kcs_bmc *kcs_bmc = &priv->kcs_bmc;
 
-	misc_deregister(&kcs_bmc->miscdev);
+	kcs_bmc_remove_device(kcs_bmc);
 
 	return 0;
 }
-- 
2.30.2


^ permalink raw reply related	[flat|nested] 23+ messages in thread

* [PATCH v4 06/16] ipmi: kcs_bmc: Split headers into device and client
  2021-06-08 10:47 [PATCH v4 00/16] ipmi: Allow raw access to KCS devices Andrew Jeffery
                   ` (4 preceding siblings ...)
  2021-06-08 10:47 ` [PATCH v4 05/16] ipmi: kcs_bmc: Turn the driver data-structures inside-out Andrew Jeffery
@ 2021-06-08 10:47 ` Andrew Jeffery
  2021-06-18 23:24   ` Zev Weiss
  2021-06-08 10:47 ` [PATCH v4 07/16] ipmi: kcs_bmc: Strip private client data from struct kcs_bmc Andrew Jeffery
                   ` (10 subsequent siblings)
  16 siblings, 1 reply; 23+ messages in thread
From: Andrew Jeffery @ 2021-06-08 10:47 UTC (permalink / raw)
  To: openipmi-developer, openbmc, minyard
  Cc: devicetree, tmaimon77, linux-aspeed, avifishman70, venture,
	linux-kernel, tali.perry1, robh+dt, chiawei_wang,
	linux-arm-kernel, benjaminfair, arnd, zweiss, joel, KWLIU

Strengthen the distinction between code that abstracts the
implementation of the KCS behaviours (device drivers) and code that
exploits KCS behaviours (clients). Neither needs to know about the APIs
required by the other, so provide separate headers.

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
---
 drivers/char/ipmi/kcs_bmc.c           | 23 ++++++++++------
 drivers/char/ipmi/kcs_bmc.h           | 27 +++++++++----------
 drivers/char/ipmi/kcs_bmc_aspeed.c    | 17 ++++++------
 drivers/char/ipmi/kcs_bmc_cdev_ipmi.c | 39 ++++++++++++++++++---------
 drivers/char/ipmi/kcs_bmc_client.h    | 27 +++++++++++++++++++
 drivers/char/ipmi/kcs_bmc_device.h    | 19 +++++++++++++
 drivers/char/ipmi/kcs_bmc_npcm7xx.c   | 17 ++++++------
 7 files changed, 117 insertions(+), 52 deletions(-)
 create mode 100644 drivers/char/ipmi/kcs_bmc_client.h
 create mode 100644 drivers/char/ipmi/kcs_bmc_device.h

diff --git a/drivers/char/ipmi/kcs_bmc.c b/drivers/char/ipmi/kcs_bmc.c
index 07bb6747f29a..c347cf6f9337 100644
--- a/drivers/char/ipmi/kcs_bmc.c
+++ b/drivers/char/ipmi/kcs_bmc.c
@@ -1,46 +1,52 @@
 // SPDX-License-Identifier: GPL-2.0
 /*
  * Copyright (c) 2015-2018, Intel Corporation.
+ * Copyright (c) 2021, IBM Corp.
  */
 
 #include <linux/module.h>
 
 #include "kcs_bmc.h"
 
+/* Implement both the device and client interfaces here */
+#include "kcs_bmc_device.h"
+#include "kcs_bmc_client.h"
+
+/* Consumer data access */
+
 u8 kcs_bmc_read_data(struct kcs_bmc *kcs_bmc)
 {
-	return kcs_bmc->io_inputb(kcs_bmc, kcs_bmc->ioreg.idr);
+	return kcs_bmc->ops->io_inputb(kcs_bmc, kcs_bmc->ioreg.idr);
 }
 EXPORT_SYMBOL(kcs_bmc_read_data);
 
 void kcs_bmc_write_data(struct kcs_bmc *kcs_bmc, u8 data)
 {
-	kcs_bmc->io_outputb(kcs_bmc, kcs_bmc->ioreg.odr, data);
+	kcs_bmc->ops->io_outputb(kcs_bmc, kcs_bmc->ioreg.odr, data);
 }
 EXPORT_SYMBOL(kcs_bmc_write_data);
 
 u8 kcs_bmc_read_status(struct kcs_bmc *kcs_bmc)
 {
-	return kcs_bmc->io_inputb(kcs_bmc, kcs_bmc->ioreg.str);
+	return kcs_bmc->ops->io_inputb(kcs_bmc, kcs_bmc->ioreg.str);
 }
 EXPORT_SYMBOL(kcs_bmc_read_status);
 
 void kcs_bmc_write_status(struct kcs_bmc *kcs_bmc, u8 data)
 {
-	kcs_bmc->io_outputb(kcs_bmc, kcs_bmc->ioreg.str, data);
+	kcs_bmc->ops->io_outputb(kcs_bmc, kcs_bmc->ioreg.str, data);
 }
 EXPORT_SYMBOL(kcs_bmc_write_status);
 
 void kcs_bmc_update_status(struct kcs_bmc *kcs_bmc, u8 mask, u8 val)
 {
-	kcs_bmc->io_updateb(kcs_bmc, kcs_bmc->ioreg.str, mask, val);
+	kcs_bmc->ops->io_updateb(kcs_bmc, kcs_bmc->ioreg.str, mask, val);
 }
 EXPORT_SYMBOL(kcs_bmc_update_status);
 
-int kcs_bmc_ipmi_event(struct kcs_bmc *kcs_bmc);
-int kcs_bmc_handle_event(struct kcs_bmc *kcs_bmc)
+irqreturn_t kcs_bmc_handle_event(struct kcs_bmc *kcs_bmc)
 {
-	return kcs_bmc_ipmi_event(kcs_bmc);
+	return kcs_bmc->client.ops->event(&kcs_bmc->client);
 }
 EXPORT_SYMBOL(kcs_bmc_handle_event);
 
@@ -62,4 +68,5 @@ EXPORT_SYMBOL(kcs_bmc_remove_device);
 
 MODULE_LICENSE("GPL v2");
 MODULE_AUTHOR("Haiyue Wang <haiyue.wang@linux.intel.com>");
+MODULE_AUTHOR("Andrew Jeffery <andrew@aj.id.au>");
 MODULE_DESCRIPTION("KCS BMC to handle the IPMI request from system software");
diff --git a/drivers/char/ipmi/kcs_bmc.h b/drivers/char/ipmi/kcs_bmc.h
index f3ed89e7da98..f42843d240ed 100644
--- a/drivers/char/ipmi/kcs_bmc.h
+++ b/drivers/char/ipmi/kcs_bmc.h
@@ -8,6 +8,12 @@
 
 #include <linux/miscdevice.h>
 
+#include "kcs_bmc_client.h"
+
+#define KCS_BMC_STR_OBF		BIT(0)
+#define KCS_BMC_STR_IBF		BIT(1)
+#define KCS_BMC_STR_CMD_DAT	BIT(3)
+
 /* Different phases of the KCS BMC module.
  *  KCS_PHASE_IDLE:
  *            BMC should not be expecting nor sending any data.
@@ -66,19 +72,21 @@ struct kcs_ioreg {
 	u32 str;
 };
 
+struct kcs_bmc_device_ops;
+
 struct kcs_bmc {
 	struct device *dev;
 
+	const struct kcs_bmc_device_ops *ops;
+
+	struct kcs_bmc_client client;
+
 	spinlock_t lock;
 
 	u32 channel;
 	int running;
 
-	/* Setup by BMC KCS controller driver */
 	struct kcs_ioreg ioreg;
-	u8 (*io_inputb)(struct kcs_bmc *kcs_bmc, u32 reg);
-	void (*io_outputb)(struct kcs_bmc *kcs_bmc, u32 reg, u8 b);
-	void (*io_updateb)(struct kcs_bmc *kcs_bmc, u32 reg, u8 mask, u8 val);
 
 	enum kcs_phases phase;
 	enum kcs_errors error;
@@ -97,15 +105,4 @@ struct kcs_bmc {
 
 	struct miscdevice miscdev;
 };
-
-int kcs_bmc_handle_event(struct kcs_bmc *kcs_bmc);
-int kcs_bmc_add_device(struct kcs_bmc *kcs_bmc);
-void kcs_bmc_remove_device(struct kcs_bmc *kcs_bmc);
-
-u8 kcs_bmc_read_data(struct kcs_bmc *kcs_bmc);
-void kcs_bmc_write_data(struct kcs_bmc *kcs_bmc, u8 data);
-u8 kcs_bmc_read_status(struct kcs_bmc *kcs_bmc);
-void kcs_bmc_write_status(struct kcs_bmc *kcs_bmc, u8 data);
-void kcs_bmc_update_status(struct kcs_bmc *kcs_bmc, u8 mask, u8 val);
-
 #endif /* __KCS_BMC_H__ */
diff --git a/drivers/char/ipmi/kcs_bmc_aspeed.c b/drivers/char/ipmi/kcs_bmc_aspeed.c
index b07cbc423dd5..fdfba745302a 100644
--- a/drivers/char/ipmi/kcs_bmc_aspeed.c
+++ b/drivers/char/ipmi/kcs_bmc_aspeed.c
@@ -21,7 +21,7 @@
 #include <linux/slab.h>
 #include <linux/timer.h>
 
-#include "kcs_bmc.h"
+#include "kcs_bmc_device.h"
 
 
 #define DEVICE_NAME     "ast-kcs-bmc"
@@ -220,14 +220,17 @@ static void aspeed_kcs_enable_channel(struct kcs_bmc *kcs_bmc, bool enable)
 	}
 }
 
+static const struct kcs_bmc_device_ops aspeed_kcs_ops = {
+	.io_inputb = aspeed_kcs_inb,
+	.io_outputb = aspeed_kcs_outb,
+	.io_updateb = aspeed_kcs_updateb,
+};
+
 static irqreturn_t aspeed_kcs_irq(int irq, void *arg)
 {
 	struct kcs_bmc *kcs_bmc = arg;
 
-	if (!kcs_bmc_handle_event(kcs_bmc))
-		return IRQ_HANDLED;
-
-	return IRQ_NONE;
+	return kcs_bmc_handle_event(kcs_bmc);
 }
 
 static int aspeed_kcs_config_irq(struct kcs_bmc *kcs_bmc,
@@ -364,9 +367,7 @@ static int aspeed_kcs_probe(struct platform_device *pdev)
 	kcs_bmc->dev = &pdev->dev;
 	kcs_bmc->channel = channel;
 	kcs_bmc->ioreg = ast_kcs_bmc_ioregs[channel - 1];
-	kcs_bmc->io_inputb = aspeed_kcs_inb;
-	kcs_bmc->io_outputb = aspeed_kcs_outb;
-	kcs_bmc->io_updateb = aspeed_kcs_updateb;
+	kcs_bmc->ops = &aspeed_kcs_ops;
 
 	priv->map = syscon_node_to_regmap(pdev->dev.parent->of_node);
 	if (IS_ERR(priv->map)) {
diff --git a/drivers/char/ipmi/kcs_bmc_cdev_ipmi.c b/drivers/char/ipmi/kcs_bmc_cdev_ipmi.c
index 5060643bf530..476ad6d541d5 100644
--- a/drivers/char/ipmi/kcs_bmc_cdev_ipmi.c
+++ b/drivers/char/ipmi/kcs_bmc_cdev_ipmi.c
@@ -22,7 +22,6 @@
 
 #define KCS_ZERO_DATA     0
 
-
 /* IPMI 2.0 - Table 9-1, KCS Interface Status Register Bits */
 #define KCS_STATUS_STATE(state) (state << 6)
 #define KCS_STATUS_STATE_MASK   GENMASK(7, 6)
@@ -179,12 +178,19 @@ static void kcs_bmc_ipmi_handle_cmd(struct kcs_bmc *kcs_bmc)
 	}
 }
 
-int kcs_bmc_ipmi_event(struct kcs_bmc *kcs_bmc);
-int kcs_bmc_ipmi_event(struct kcs_bmc *kcs_bmc)
+static inline struct kcs_bmc *client_to_kcs_bmc(struct kcs_bmc_client *client)
 {
+	return container_of(client, struct kcs_bmc, client);
+}
+
+static irqreturn_t kcs_bmc_ipmi_event(struct kcs_bmc_client *client)
+{
+	struct kcs_bmc *kcs_bmc;
 	unsigned long flags;
-	int ret = -ENODATA;
 	u8 status;
+	int ret;
+
+	kcs_bmc = client_to_kcs_bmc(client);
 
 	spin_lock_irqsave(&kcs_bmc->lock, flags);
 
@@ -197,23 +203,28 @@ int kcs_bmc_ipmi_event(struct kcs_bmc *kcs_bmc)
 		else
 			kcs_bmc_ipmi_handle_data(kcs_bmc);
 
-		ret = 0;
+		ret = IRQ_HANDLED;
+	} else {
+		ret = IRQ_NONE;
 	}
 
 	spin_unlock_irqrestore(&kcs_bmc->lock, flags);
 
 	return ret;
 }
-EXPORT_SYMBOL(kcs_bmc_ipmi_event);
 
-static inline struct kcs_bmc *to_kcs_bmc(struct file *filp)
+static const struct kcs_bmc_client_ops kcs_bmc_ipmi_client_ops = {
+	.event = kcs_bmc_ipmi_event,
+};
+
+static inline struct kcs_bmc *file_to_kcs_bmc(struct file *filp)
 {
 	return container_of(filp->private_data, struct kcs_bmc, miscdev);
 }
 
 static int kcs_bmc_ipmi_open(struct inode *inode, struct file *filp)
 {
-	struct kcs_bmc *kcs_bmc = to_kcs_bmc(filp);
+	struct kcs_bmc *kcs_bmc = file_to_kcs_bmc(filp);
 	int ret = 0;
 
 	spin_lock_irq(&kcs_bmc->lock);
@@ -228,7 +239,7 @@ static int kcs_bmc_ipmi_open(struct inode *inode, struct file *filp)
 
 static __poll_t kcs_bmc_ipmi_poll(struct file *filp, poll_table *wait)
 {
-	struct kcs_bmc *kcs_bmc = to_kcs_bmc(filp);
+	struct kcs_bmc *kcs_bmc = file_to_kcs_bmc(filp);
 	__poll_t mask = 0;
 
 	poll_wait(filp, &kcs_bmc->queue, wait);
@@ -244,7 +255,7 @@ static __poll_t kcs_bmc_ipmi_poll(struct file *filp, poll_table *wait)
 static ssize_t kcs_bmc_ipmi_read(struct file *filp, char __user *buf,
 			    size_t count, loff_t *ppos)
 {
-	struct kcs_bmc *kcs_bmc = to_kcs_bmc(filp);
+	struct kcs_bmc *kcs_bmc = file_to_kcs_bmc(filp);
 	bool data_avail;
 	size_t data_len;
 	ssize_t ret;
@@ -306,7 +317,7 @@ static ssize_t kcs_bmc_ipmi_read(struct file *filp, char __user *buf,
 static ssize_t kcs_bmc_ipmi_write(struct file *filp, const char __user *buf,
 			     size_t count, loff_t *ppos)
 {
-	struct kcs_bmc *kcs_bmc = to_kcs_bmc(filp);
+	struct kcs_bmc *kcs_bmc = file_to_kcs_bmc(filp);
 	ssize_t ret;
 
 	/* a minimum response size '3' : netfn + cmd + ccode */
@@ -342,7 +353,7 @@ static ssize_t kcs_bmc_ipmi_write(struct file *filp, const char __user *buf,
 static long kcs_bmc_ipmi_ioctl(struct file *filp, unsigned int cmd,
 			  unsigned long arg)
 {
-	struct kcs_bmc *kcs_bmc = to_kcs_bmc(filp);
+	struct kcs_bmc *kcs_bmc = file_to_kcs_bmc(filp);
 	long ret = 0;
 
 	spin_lock_irq(&kcs_bmc->lock);
@@ -372,7 +383,7 @@ static long kcs_bmc_ipmi_ioctl(struct file *filp, unsigned int cmd,
 
 static int kcs_bmc_ipmi_release(struct inode *inode, struct file *filp)
 {
-	struct kcs_bmc *kcs_bmc = to_kcs_bmc(filp);
+	struct kcs_bmc *kcs_bmc = file_to_kcs_bmc(filp);
 
 	spin_lock_irq(&kcs_bmc->lock);
 	kcs_bmc->running = 0;
@@ -401,6 +412,8 @@ int kcs_bmc_ipmi_add_device(struct kcs_bmc *kcs_bmc)
 	mutex_init(&kcs_bmc->mutex);
 	init_waitqueue_head(&kcs_bmc->queue);
 
+	kcs_bmc->client.dev = kcs_bmc;
+	kcs_bmc->client.ops = &kcs_bmc_ipmi_client_ops;
 	kcs_bmc->data_in = devm_kmalloc(kcs_bmc->dev, KCS_MSG_BUFSIZ, GFP_KERNEL);
 	kcs_bmc->data_out = devm_kmalloc(kcs_bmc->dev, KCS_MSG_BUFSIZ, GFP_KERNEL);
 	kcs_bmc->kbuffer = devm_kmalloc(kcs_bmc->dev, KCS_MSG_BUFSIZ, GFP_KERNEL);
diff --git a/drivers/char/ipmi/kcs_bmc_client.h b/drivers/char/ipmi/kcs_bmc_client.h
new file mode 100644
index 000000000000..dad8774aebce
--- /dev/null
+++ b/drivers/char/ipmi/kcs_bmc_client.h
@@ -0,0 +1,27 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (c) 2021, IBM Corp. */
+
+#ifndef __KCS_BMC_CONSUMER_H__
+#define __KCS_BMC_CONSUMER_H__
+
+#include <linux/irqreturn.h>
+
+struct kcs_bmc;
+struct kcs_bmc_client_ops;
+
+struct kcs_bmc_client {
+	const struct kcs_bmc_client_ops *ops;
+
+	struct kcs_bmc *dev;
+};
+
+struct kcs_bmc_client_ops {
+	irqreturn_t (*event)(struct kcs_bmc_client *client);
+};
+
+u8 kcs_bmc_read_data(struct kcs_bmc *kcs_bmc);
+void kcs_bmc_write_data(struct kcs_bmc *kcs_bmc, u8 data);
+u8 kcs_bmc_read_status(struct kcs_bmc *kcs_bmc);
+void kcs_bmc_write_status(struct kcs_bmc *kcs_bmc, u8 data);
+void kcs_bmc_update_status(struct kcs_bmc *kcs_bmc, u8 mask, u8 val);
+#endif
diff --git a/drivers/char/ipmi/kcs_bmc_device.h b/drivers/char/ipmi/kcs_bmc_device.h
new file mode 100644
index 000000000000..dd8bf1307ad2
--- /dev/null
+++ b/drivers/char/ipmi/kcs_bmc_device.h
@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (c) 2021, IBM Corp. */
+
+#ifndef __KCS_BMC_DEVICE_H__
+#define __KCS_BMC_DEVICE_H__
+
+#include "kcs_bmc.h"
+
+struct kcs_bmc_device_ops {
+	u8 (*io_inputb)(struct kcs_bmc *kcs_bmc, u32 reg);
+	void (*io_outputb)(struct kcs_bmc *kcs_bmc, u32 reg, u8 b);
+	void (*io_updateb)(struct kcs_bmc *kcs_bmc, u32 reg, u8 mask, u8 b);
+};
+
+irqreturn_t kcs_bmc_handle_event(struct kcs_bmc *kcs_bmc);
+int kcs_bmc_add_device(struct kcs_bmc *kcs_bmc);
+void kcs_bmc_remove_device(struct kcs_bmc *kcs_bmc);
+
+#endif
diff --git a/drivers/char/ipmi/kcs_bmc_npcm7xx.c b/drivers/char/ipmi/kcs_bmc_npcm7xx.c
index e06250285113..ebb691af28c5 100644
--- a/drivers/char/ipmi/kcs_bmc_npcm7xx.c
+++ b/drivers/char/ipmi/kcs_bmc_npcm7xx.c
@@ -17,7 +17,7 @@
 #include <linux/regmap.h>
 #include <linux/slab.h>
 
-#include "kcs_bmc.h"
+#include "kcs_bmc_device.h"
 
 #define DEVICE_NAME	"npcm-kcs-bmc"
 #define KCS_CHANNEL_MAX	3
@@ -128,10 +128,7 @@ static irqreturn_t npcm7xx_kcs_irq(int irq, void *arg)
 {
 	struct kcs_bmc *kcs_bmc = arg;
 
-	if (!kcs_bmc_handle_event(kcs_bmc))
-		return IRQ_HANDLED;
-
-	return IRQ_NONE;
+	return kcs_bmc_handle_event(kcs_bmc);
 }
 
 static int npcm7xx_kcs_config_irq(struct kcs_bmc *kcs_bmc,
@@ -148,6 +145,12 @@ static int npcm7xx_kcs_config_irq(struct kcs_bmc *kcs_bmc,
 				dev_name(dev), kcs_bmc);
 }
 
+static const struct kcs_bmc_device_ops npcm7xx_kcs_ops = {
+	.io_inputb = npcm7xx_kcs_inb,
+	.io_outputb = npcm7xx_kcs_outb,
+	.io_updateb = npcm7xx_kcs_updateb,
+};
+
 static int npcm7xx_kcs_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
@@ -179,9 +182,7 @@ static int npcm7xx_kcs_probe(struct platform_device *pdev)
 	kcs_bmc->ioreg.idr = priv->reg->dib;
 	kcs_bmc->ioreg.odr = priv->reg->dob;
 	kcs_bmc->ioreg.str = priv->reg->sts;
-	kcs_bmc->io_inputb = npcm7xx_kcs_inb;
-	kcs_bmc->io_outputb = npcm7xx_kcs_outb;
-	kcs_bmc->io_updateb = npcm7xx_kcs_updateb;
+	kcs_bmc->ops = &npcm7xx_kcs_ops;
 
 	platform_set_drvdata(pdev, priv);
 
-- 
2.30.2


^ permalink raw reply related	[flat|nested] 23+ messages in thread

* [PATCH v4 07/16] ipmi: kcs_bmc: Strip private client data from struct kcs_bmc
  2021-06-08 10:47 [PATCH v4 00/16] ipmi: Allow raw access to KCS devices Andrew Jeffery
                   ` (5 preceding siblings ...)
  2021-06-08 10:47 ` [PATCH v4 06/16] ipmi: kcs_bmc: Split headers into device and client Andrew Jeffery
@ 2021-06-08 10:47 ` Andrew Jeffery
  2021-06-08 10:47 ` [PATCH v4 08/16] ipmi: kcs_bmc: Decouple the IPMI chardev from the core Andrew Jeffery
                   ` (9 subsequent siblings)
  16 siblings, 0 replies; 23+ messages in thread
From: Andrew Jeffery @ 2021-06-08 10:47 UTC (permalink / raw)
  To: openipmi-developer, openbmc, minyard
  Cc: devicetree, tmaimon77, linux-aspeed, avifishman70, venture,
	linux-kernel, tali.perry1, robh+dt, chiawei_wang,
	linux-arm-kernel, benjaminfair, arnd, zweiss, joel, KWLIU

Move all client-private data out of `struct kcs_bmc` into the KCS client
implementation.

With this change the KCS BMC core code now only concerns itself with
abstract `struct kcs_bmc` and `struct kcs_bmc_client` types, achieving
expected separation of concerns. Further, the change clears the path for
implementation of alternative userspace interfaces.

The chardev data-structures are rearranged in the same manner applied to
the KCS device driver data-structures in an earlier patch - `struct
kcs_bmc_client` is embedded in the client's private data and we exploit
container_of() to translate as required.

Finally, now that it is free of client data, `struct kcs_bmc` is renamed
to `struct kcs_bmc_device` to contrast `struct kcs_bmc_client`.

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Reviewed-by: Zev Weiss <zweiss@equinix.com>
---
 drivers/char/ipmi/kcs_bmc.c           |  70 ++++-
 drivers/char/ipmi/kcs_bmc.h           |  83 +----
 drivers/char/ipmi/kcs_bmc_aspeed.c    |  22 +-
 drivers/char/ipmi/kcs_bmc_cdev_ipmi.c | 428 ++++++++++++++++----------
 drivers/char/ipmi/kcs_bmc_client.h    |  28 +-
 drivers/char/ipmi/kcs_bmc_device.h    |  14 +-
 drivers/char/ipmi/kcs_bmc_npcm7xx.c   |  20 +-
 7 files changed, 369 insertions(+), 296 deletions(-)

diff --git a/drivers/char/ipmi/kcs_bmc.c b/drivers/char/ipmi/kcs_bmc.c
index c347cf6f9337..2ec934f0dba3 100644
--- a/drivers/char/ipmi/kcs_bmc.c
+++ b/drivers/char/ipmi/kcs_bmc.c
@@ -4,6 +4,7 @@
  * Copyright (c) 2021, IBM Corp.
  */
 
+#include <linux/device.h>
 #include <linux/module.h>
 
 #include "kcs_bmc.h"
@@ -14,51 +15,98 @@
 
 /* Consumer data access */
 
-u8 kcs_bmc_read_data(struct kcs_bmc *kcs_bmc)
+u8 kcs_bmc_read_data(struct kcs_bmc_device *kcs_bmc)
 {
 	return kcs_bmc->ops->io_inputb(kcs_bmc, kcs_bmc->ioreg.idr);
 }
 EXPORT_SYMBOL(kcs_bmc_read_data);
 
-void kcs_bmc_write_data(struct kcs_bmc *kcs_bmc, u8 data)
+void kcs_bmc_write_data(struct kcs_bmc_device *kcs_bmc, u8 data)
 {
 	kcs_bmc->ops->io_outputb(kcs_bmc, kcs_bmc->ioreg.odr, data);
 }
 EXPORT_SYMBOL(kcs_bmc_write_data);
 
-u8 kcs_bmc_read_status(struct kcs_bmc *kcs_bmc)
+u8 kcs_bmc_read_status(struct kcs_bmc_device *kcs_bmc)
 {
 	return kcs_bmc->ops->io_inputb(kcs_bmc, kcs_bmc->ioreg.str);
 }
 EXPORT_SYMBOL(kcs_bmc_read_status);
 
-void kcs_bmc_write_status(struct kcs_bmc *kcs_bmc, u8 data)
+void kcs_bmc_write_status(struct kcs_bmc_device *kcs_bmc, u8 data)
 {
 	kcs_bmc->ops->io_outputb(kcs_bmc, kcs_bmc->ioreg.str, data);
 }
 EXPORT_SYMBOL(kcs_bmc_write_status);
 
-void kcs_bmc_update_status(struct kcs_bmc *kcs_bmc, u8 mask, u8 val)
+void kcs_bmc_update_status(struct kcs_bmc_device *kcs_bmc, u8 mask, u8 val)
 {
 	kcs_bmc->ops->io_updateb(kcs_bmc, kcs_bmc->ioreg.str, mask, val);
 }
 EXPORT_SYMBOL(kcs_bmc_update_status);
 
-irqreturn_t kcs_bmc_handle_event(struct kcs_bmc *kcs_bmc)
+irqreturn_t kcs_bmc_handle_event(struct kcs_bmc_device *kcs_bmc)
 {
-	return kcs_bmc->client.ops->event(&kcs_bmc->client);
+	struct kcs_bmc_client *client;
+	irqreturn_t rc;
+
+	spin_lock(&kcs_bmc->lock);
+	client = kcs_bmc->client;
+	if (client) {
+		rc = client->ops->event(client);
+	} else {
+		u8 status;
+
+		status = kcs_bmc_read_status(kcs_bmc);
+		if (status & KCS_BMC_STR_IBF) {
+			/* Ack the event by reading the data */
+			kcs_bmc_read_data(kcs_bmc);
+			rc = IRQ_HANDLED;
+		} else {
+			rc = IRQ_NONE;
+		}
+	}
+	spin_unlock(&kcs_bmc->lock);
+
+	return rc;
 }
 EXPORT_SYMBOL(kcs_bmc_handle_event);
 
-int kcs_bmc_ipmi_add_device(struct kcs_bmc *kcs_bmc);
-int kcs_bmc_add_device(struct kcs_bmc *kcs_bmc)
+int kcs_bmc_enable_device(struct kcs_bmc_device *kcs_bmc, struct kcs_bmc_client *client)
+{
+	int rc;
+
+	spin_lock_irq(&kcs_bmc->lock);
+	if (kcs_bmc->client) {
+		rc = -EBUSY;
+	} else {
+		kcs_bmc->client = client;
+		rc = 0;
+	}
+	spin_unlock_irq(&kcs_bmc->lock);
+
+	return rc;
+}
+EXPORT_SYMBOL(kcs_bmc_enable_device);
+
+void kcs_bmc_disable_device(struct kcs_bmc_device *kcs_bmc, struct kcs_bmc_client *client)
+{
+	spin_lock_irq(&kcs_bmc->lock);
+	if (client == kcs_bmc->client)
+		kcs_bmc->client = NULL;
+	spin_unlock_irq(&kcs_bmc->lock);
+}
+EXPORT_SYMBOL(kcs_bmc_disable_device);
+
+int kcs_bmc_ipmi_add_device(struct kcs_bmc_device *kcs_bmc);
+int kcs_bmc_add_device(struct kcs_bmc_device *kcs_bmc)
 {
 	return kcs_bmc_ipmi_add_device(kcs_bmc);
 }
 EXPORT_SYMBOL(kcs_bmc_add_device);
 
-int kcs_bmc_ipmi_remove_device(struct kcs_bmc *kcs_bmc);
-void kcs_bmc_remove_device(struct kcs_bmc *kcs_bmc)
+int kcs_bmc_ipmi_remove_device(struct kcs_bmc_device *kcs_bmc);
+void kcs_bmc_remove_device(struct kcs_bmc_device *kcs_bmc)
 {
 	if (kcs_bmc_ipmi_remove_device(kcs_bmc))
 		pr_warn("Failed to remove device for KCS channel %d\n",
diff --git a/drivers/char/ipmi/kcs_bmc.h b/drivers/char/ipmi/kcs_bmc.h
index f42843d240ed..3f0cce315b4f 100644
--- a/drivers/char/ipmi/kcs_bmc.h
+++ b/drivers/char/ipmi/kcs_bmc.h
@@ -6,61 +6,12 @@
 #ifndef __KCS_BMC_H__
 #define __KCS_BMC_H__
 
-#include <linux/miscdevice.h>
-
-#include "kcs_bmc_client.h"
+#include <linux/list.h>
 
 #define KCS_BMC_STR_OBF		BIT(0)
 #define KCS_BMC_STR_IBF		BIT(1)
 #define KCS_BMC_STR_CMD_DAT	BIT(3)
 
-/* Different phases of the KCS BMC module.
- *  KCS_PHASE_IDLE:
- *            BMC should not be expecting nor sending any data.
- *  KCS_PHASE_WRITE_START:
- *            BMC is receiving a WRITE_START command from system software.
- *  KCS_PHASE_WRITE_DATA:
- *            BMC is receiving a data byte from system software.
- *  KCS_PHASE_WRITE_END_CMD:
- *            BMC is waiting a last data byte from system software.
- *  KCS_PHASE_WRITE_DONE:
- *            BMC has received the whole request from system software.
- *  KCS_PHASE_WAIT_READ:
- *            BMC is waiting the response from the upper IPMI service.
- *  KCS_PHASE_READ:
- *            BMC is transferring the response to system software.
- *  KCS_PHASE_ABORT_ERROR1:
- *            BMC is waiting error status request from system software.
- *  KCS_PHASE_ABORT_ERROR2:
- *            BMC is waiting for idle status afer error from system software.
- *  KCS_PHASE_ERROR:
- *            BMC has detected a protocol violation at the interface level.
- */
-enum kcs_phases {
-	KCS_PHASE_IDLE,
-
-	KCS_PHASE_WRITE_START,
-	KCS_PHASE_WRITE_DATA,
-	KCS_PHASE_WRITE_END_CMD,
-	KCS_PHASE_WRITE_DONE,
-
-	KCS_PHASE_WAIT_READ,
-	KCS_PHASE_READ,
-
-	KCS_PHASE_ABORT_ERROR1,
-	KCS_PHASE_ABORT_ERROR2,
-	KCS_PHASE_ERROR
-};
-
-/* IPMI 2.0 - Table 9-4, KCS Interface Status Codes */
-enum kcs_errors {
-	KCS_NO_ERROR                = 0x00,
-	KCS_ABORTED_BY_COMMAND      = 0x01,
-	KCS_ILLEGAL_CONTROL_CODE    = 0x02,
-	KCS_LENGTH_ERROR            = 0x06,
-	KCS_UNSPECIFIED_ERROR       = 0xFF
-};
-
 /* IPMI 2.0 - 9.5, KCS Interface Registers
  * @idr: Input Data Register
  * @odr: Output Data Register
@@ -73,36 +24,20 @@ struct kcs_ioreg {
 };
 
 struct kcs_bmc_device_ops;
+struct kcs_bmc_client;
+
+struct kcs_bmc_device {
+	struct list_head entry;
 
-struct kcs_bmc {
 	struct device *dev;
-
-	const struct kcs_bmc_device_ops *ops;
-
-	struct kcs_bmc_client client;
-
-	spinlock_t lock;
-
 	u32 channel;
-	int running;
 
 	struct kcs_ioreg ioreg;
 
-	enum kcs_phases phase;
-	enum kcs_errors error;
+	const struct kcs_bmc_device_ops *ops;
 
-	wait_queue_head_t queue;
-	bool data_in_avail;
-	int  data_in_idx;
-	u8  *data_in;
-
-	int  data_out_idx;
-	int  data_out_len;
-	u8  *data_out;
-
-	struct mutex mutex;
-	u8 *kbuffer;
-
-	struct miscdevice miscdev;
+	spinlock_t lock;
+	struct kcs_bmc_client *client;
 };
+
 #endif /* __KCS_BMC_H__ */
diff --git a/drivers/char/ipmi/kcs_bmc_aspeed.c b/drivers/char/ipmi/kcs_bmc_aspeed.c
index fdfba745302a..08d4290464d8 100644
--- a/drivers/char/ipmi/kcs_bmc_aspeed.c
+++ b/drivers/char/ipmi/kcs_bmc_aspeed.c
@@ -61,7 +61,7 @@
 #define LPC_STR4             0x11C
 
 struct aspeed_kcs_bmc {
-	struct kcs_bmc kcs_bmc;
+	struct kcs_bmc_device kcs_bmc;
 
 	struct regmap *map;
 };
@@ -71,12 +71,12 @@ struct aspeed_kcs_of_ops {
 	int (*get_io_address)(struct platform_device *pdev);
 };
 
-static inline struct aspeed_kcs_bmc *to_aspeed_kcs_bmc(struct kcs_bmc *kcs_bmc)
+static inline struct aspeed_kcs_bmc *to_aspeed_kcs_bmc(struct kcs_bmc_device *kcs_bmc)
 {
 	return container_of(kcs_bmc, struct aspeed_kcs_bmc, kcs_bmc);
 }
 
-static u8 aspeed_kcs_inb(struct kcs_bmc *kcs_bmc, u32 reg)
+static u8 aspeed_kcs_inb(struct kcs_bmc_device *kcs_bmc, u32 reg)
 {
 	struct aspeed_kcs_bmc *priv = to_aspeed_kcs_bmc(kcs_bmc);
 	u32 val = 0;
@@ -88,7 +88,7 @@ static u8 aspeed_kcs_inb(struct kcs_bmc *kcs_bmc, u32 reg)
 	return rc == 0 ? (u8) val : 0;
 }
 
-static void aspeed_kcs_outb(struct kcs_bmc *kcs_bmc, u32 reg, u8 data)
+static void aspeed_kcs_outb(struct kcs_bmc_device *kcs_bmc, u32 reg, u8 data)
 {
 	struct aspeed_kcs_bmc *priv = to_aspeed_kcs_bmc(kcs_bmc);
 	int rc;
@@ -97,7 +97,7 @@ static void aspeed_kcs_outb(struct kcs_bmc *kcs_bmc, u32 reg, u8 data)
 	WARN(rc != 0, "regmap_write() failed: %d\n", rc);
 }
 
-static void aspeed_kcs_updateb(struct kcs_bmc *kcs_bmc, u32 reg, u8 mask, u8 val)
+static void aspeed_kcs_updateb(struct kcs_bmc_device *kcs_bmc, u32 reg, u8 mask, u8 val)
 {
 	struct aspeed_kcs_bmc *priv = to_aspeed_kcs_bmc(kcs_bmc);
 	int rc;
@@ -119,7 +119,7 @@ static void aspeed_kcs_updateb(struct kcs_bmc *kcs_bmc, u32 reg, u8 mask, u8 val
  *     C. KCS4
  *        D / C : CA4h / CA5h
  */
-static void aspeed_kcs_set_address(struct kcs_bmc *kcs_bmc, u16 addr)
+static void aspeed_kcs_set_address(struct kcs_bmc_device *kcs_bmc, u16 addr)
 {
 	struct aspeed_kcs_bmc *priv = to_aspeed_kcs_bmc(kcs_bmc);
 
@@ -153,7 +153,7 @@ static void aspeed_kcs_set_address(struct kcs_bmc *kcs_bmc, u16 addr)
 	}
 }
 
-static void aspeed_kcs_enable_channel(struct kcs_bmc *kcs_bmc, bool enable)
+static void aspeed_kcs_enable_channel(struct kcs_bmc_device *kcs_bmc, bool enable)
 {
 	struct aspeed_kcs_bmc *priv = to_aspeed_kcs_bmc(kcs_bmc);
 
@@ -228,12 +228,12 @@ static const struct kcs_bmc_device_ops aspeed_kcs_ops = {
 
 static irqreturn_t aspeed_kcs_irq(int irq, void *arg)
 {
-	struct kcs_bmc *kcs_bmc = arg;
+	struct kcs_bmc_device *kcs_bmc = arg;
 
 	return kcs_bmc_handle_event(kcs_bmc);
 }
 
-static int aspeed_kcs_config_irq(struct kcs_bmc *kcs_bmc,
+static int aspeed_kcs_config_irq(struct kcs_bmc_device *kcs_bmc,
 			struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
@@ -335,8 +335,8 @@ static int aspeed_kcs_of_v2_get_io_address(struct platform_device *pdev)
 static int aspeed_kcs_probe(struct platform_device *pdev)
 {
 	const struct aspeed_kcs_of_ops *ops;
+	struct kcs_bmc_device *kcs_bmc;
 	struct aspeed_kcs_bmc *priv;
-	struct kcs_bmc *kcs_bmc;
 	struct device_node *np;
 	int rc, channel, addr;
 
@@ -399,7 +399,7 @@ static int aspeed_kcs_probe(struct platform_device *pdev)
 static int aspeed_kcs_remove(struct platform_device *pdev)
 {
 	struct aspeed_kcs_bmc *priv = platform_get_drvdata(pdev);
-	struct kcs_bmc *kcs_bmc = &priv->kcs_bmc;
+	struct kcs_bmc_device *kcs_bmc = &priv->kcs_bmc;
 
 	kcs_bmc_remove_device(kcs_bmc);
 
diff --git a/drivers/char/ipmi/kcs_bmc_cdev_ipmi.c b/drivers/char/ipmi/kcs_bmc_cdev_ipmi.c
index 476ad6d541d5..865d8b93f3b7 100644
--- a/drivers/char/ipmi/kcs_bmc_cdev_ipmi.c
+++ b/drivers/char/ipmi/kcs_bmc_cdev_ipmi.c
@@ -8,13 +8,88 @@
 #include <linux/errno.h>
 #include <linux/io.h>
 #include <linux/ipmi_bmc.h>
+#include <linux/list.h>
+#include <linux/miscdevice.h>
 #include <linux/module.h>
+#include <linux/mutex.h>
 #include <linux/platform_device.h>
 #include <linux/poll.h>
 #include <linux/sched.h>
 #include <linux/slab.h>
 
-#include "kcs_bmc.h"
+#include "kcs_bmc_client.h"
+
+/* Different phases of the KCS BMC module.
+ *  KCS_PHASE_IDLE:
+ *            BMC should not be expecting nor sending any data.
+ *  KCS_PHASE_WRITE_START:
+ *            BMC is receiving a WRITE_START command from system software.
+ *  KCS_PHASE_WRITE_DATA:
+ *            BMC is receiving a data byte from system software.
+ *  KCS_PHASE_WRITE_END_CMD:
+ *            BMC is waiting a last data byte from system software.
+ *  KCS_PHASE_WRITE_DONE:
+ *            BMC has received the whole request from system software.
+ *  KCS_PHASE_WAIT_READ:
+ *            BMC is waiting the response from the upper IPMI service.
+ *  KCS_PHASE_READ:
+ *            BMC is transferring the response to system software.
+ *  KCS_PHASE_ABORT_ERROR1:
+ *            BMC is waiting error status request from system software.
+ *  KCS_PHASE_ABORT_ERROR2:
+ *            BMC is waiting for idle status afer error from system software.
+ *  KCS_PHASE_ERROR:
+ *            BMC has detected a protocol violation at the interface level.
+ */
+enum kcs_ipmi_phases {
+	KCS_PHASE_IDLE,
+
+	KCS_PHASE_WRITE_START,
+	KCS_PHASE_WRITE_DATA,
+	KCS_PHASE_WRITE_END_CMD,
+	KCS_PHASE_WRITE_DONE,
+
+	KCS_PHASE_WAIT_READ,
+	KCS_PHASE_READ,
+
+	KCS_PHASE_ABORT_ERROR1,
+	KCS_PHASE_ABORT_ERROR2,
+	KCS_PHASE_ERROR
+};
+
+/* IPMI 2.0 - Table 9-4, KCS Interface Status Codes */
+enum kcs_ipmi_errors {
+	KCS_NO_ERROR                = 0x00,
+	KCS_ABORTED_BY_COMMAND      = 0x01,
+	KCS_ILLEGAL_CONTROL_CODE    = 0x02,
+	KCS_LENGTH_ERROR            = 0x06,
+	KCS_UNSPECIFIED_ERROR       = 0xFF
+};
+
+struct kcs_bmc_ipmi {
+	struct list_head entry;
+
+	struct kcs_bmc_client client;
+
+	spinlock_t lock;
+
+	enum kcs_ipmi_phases phase;
+	enum kcs_ipmi_errors error;
+
+	wait_queue_head_t queue;
+	bool data_in_avail;
+	int  data_in_idx;
+	u8  *data_in;
+
+	int  data_out_idx;
+	int  data_out_len;
+	u8  *data_out;
+
+	struct mutex mutex;
+	u8 *kbuffer;
+
+	struct miscdevice miscdev;
+};
 
 #define DEVICE_NAME "ipmi-kcs"
 
@@ -44,171 +119,169 @@ enum kcs_states {
 #define KCS_CMD_WRITE_END         0x62
 #define KCS_CMD_READ_BYTE         0x68
 
-static inline void set_state(struct kcs_bmc *kcs_bmc, u8 state)
+static inline void set_state(struct kcs_bmc_ipmi *priv, u8 state)
 {
-	kcs_bmc_update_status(kcs_bmc, KCS_STATUS_STATE_MASK,
-					KCS_STATUS_STATE(state));
+	kcs_bmc_update_status(priv->client.dev, KCS_STATUS_STATE_MASK, KCS_STATUS_STATE(state));
 }
 
-static void kcs_bmc_ipmi_force_abort(struct kcs_bmc *kcs_bmc)
+static void kcs_bmc_ipmi_force_abort(struct kcs_bmc_ipmi *priv)
 {
-	set_state(kcs_bmc, ERROR_STATE);
-	kcs_bmc_read_data(kcs_bmc);
-	kcs_bmc_write_data(kcs_bmc, KCS_ZERO_DATA);
+	set_state(priv, ERROR_STATE);
+	kcs_bmc_read_data(priv->client.dev);
+	kcs_bmc_write_data(priv->client.dev, KCS_ZERO_DATA);
 
-	kcs_bmc->phase = KCS_PHASE_ERROR;
-	kcs_bmc->data_in_avail = false;
-	kcs_bmc->data_in_idx = 0;
+	priv->phase = KCS_PHASE_ERROR;
+	priv->data_in_avail = false;
+	priv->data_in_idx = 0;
 }
 
-static void kcs_bmc_ipmi_handle_data(struct kcs_bmc *kcs_bmc)
+static void kcs_bmc_ipmi_handle_data(struct kcs_bmc_ipmi *priv)
 {
+	struct kcs_bmc_device *dev;
 	u8 data;
 
-	switch (kcs_bmc->phase) {
+	dev = priv->client.dev;
+
+	switch (priv->phase) {
 	case KCS_PHASE_WRITE_START:
-		kcs_bmc->phase = KCS_PHASE_WRITE_DATA;
+		priv->phase = KCS_PHASE_WRITE_DATA;
 		fallthrough;
 
 	case KCS_PHASE_WRITE_DATA:
-		if (kcs_bmc->data_in_idx < KCS_MSG_BUFSIZ) {
-			set_state(kcs_bmc, WRITE_STATE);
-			kcs_bmc_write_data(kcs_bmc, KCS_ZERO_DATA);
-			kcs_bmc->data_in[kcs_bmc->data_in_idx++] =
-						kcs_bmc_read_data(kcs_bmc);
+		if (priv->data_in_idx < KCS_MSG_BUFSIZ) {
+			set_state(priv, WRITE_STATE);
+			kcs_bmc_write_data(dev, KCS_ZERO_DATA);
+			priv->data_in[priv->data_in_idx++] = kcs_bmc_read_data(dev);
 		} else {
-			kcs_bmc_ipmi_force_abort(kcs_bmc);
-			kcs_bmc->error = KCS_LENGTH_ERROR;
+			kcs_bmc_ipmi_force_abort(priv);
+			priv->error = KCS_LENGTH_ERROR;
 		}
 		break;
 
 	case KCS_PHASE_WRITE_END_CMD:
-		if (kcs_bmc->data_in_idx < KCS_MSG_BUFSIZ) {
-			set_state(kcs_bmc, READ_STATE);
-			kcs_bmc->data_in[kcs_bmc->data_in_idx++] =
-						kcs_bmc_read_data(kcs_bmc);
-			kcs_bmc->phase = KCS_PHASE_WRITE_DONE;
-			kcs_bmc->data_in_avail = true;
-			wake_up_interruptible(&kcs_bmc->queue);
+		if (priv->data_in_idx < KCS_MSG_BUFSIZ) {
+			set_state(priv, READ_STATE);
+			priv->data_in[priv->data_in_idx++] = kcs_bmc_read_data(dev);
+			priv->phase = KCS_PHASE_WRITE_DONE;
+			priv->data_in_avail = true;
+			wake_up_interruptible(&priv->queue);
 		} else {
-			kcs_bmc_ipmi_force_abort(kcs_bmc);
-			kcs_bmc->error = KCS_LENGTH_ERROR;
+			kcs_bmc_ipmi_force_abort(priv);
+			priv->error = KCS_LENGTH_ERROR;
 		}
 		break;
 
 	case KCS_PHASE_READ:
-		if (kcs_bmc->data_out_idx == kcs_bmc->data_out_len)
-			set_state(kcs_bmc, IDLE_STATE);
+		if (priv->data_out_idx == priv->data_out_len)
+			set_state(priv, IDLE_STATE);
 
-		data = kcs_bmc_read_data(kcs_bmc);
+		data = kcs_bmc_read_data(dev);
 		if (data != KCS_CMD_READ_BYTE) {
-			set_state(kcs_bmc, ERROR_STATE);
-			kcs_bmc_write_data(kcs_bmc, KCS_ZERO_DATA);
+			set_state(priv, ERROR_STATE);
+			kcs_bmc_write_data(dev, KCS_ZERO_DATA);
 			break;
 		}
 
-		if (kcs_bmc->data_out_idx == kcs_bmc->data_out_len) {
-			kcs_bmc_write_data(kcs_bmc, KCS_ZERO_DATA);
-			kcs_bmc->phase = KCS_PHASE_IDLE;
+		if (priv->data_out_idx == priv->data_out_len) {
+			kcs_bmc_write_data(dev, KCS_ZERO_DATA);
+			priv->phase = KCS_PHASE_IDLE;
 			break;
 		}
 
-		kcs_bmc_write_data(kcs_bmc,
-			kcs_bmc->data_out[kcs_bmc->data_out_idx++]);
+		kcs_bmc_write_data(dev, priv->data_out[priv->data_out_idx++]);
 		break;
 
 	case KCS_PHASE_ABORT_ERROR1:
-		set_state(kcs_bmc, READ_STATE);
-		kcs_bmc_read_data(kcs_bmc);
-		kcs_bmc_write_data(kcs_bmc, kcs_bmc->error);
-		kcs_bmc->phase = KCS_PHASE_ABORT_ERROR2;
+		set_state(priv, READ_STATE);
+		kcs_bmc_read_data(dev);
+		kcs_bmc_write_data(dev, priv->error);
+		priv->phase = KCS_PHASE_ABORT_ERROR2;
 		break;
 
 	case KCS_PHASE_ABORT_ERROR2:
-		set_state(kcs_bmc, IDLE_STATE);
-		kcs_bmc_read_data(kcs_bmc);
-		kcs_bmc_write_data(kcs_bmc, KCS_ZERO_DATA);
-		kcs_bmc->phase = KCS_PHASE_IDLE;
+		set_state(priv, IDLE_STATE);
+		kcs_bmc_read_data(dev);
+		kcs_bmc_write_data(dev, KCS_ZERO_DATA);
+		priv->phase = KCS_PHASE_IDLE;
 		break;
 
 	default:
-		kcs_bmc_ipmi_force_abort(kcs_bmc);
+		kcs_bmc_ipmi_force_abort(priv);
 		break;
 	}
 }
 
-static void kcs_bmc_ipmi_handle_cmd(struct kcs_bmc *kcs_bmc)
+static void kcs_bmc_ipmi_handle_cmd(struct kcs_bmc_ipmi *priv)
 {
 	u8 cmd;
 
-	set_state(kcs_bmc, WRITE_STATE);
-	kcs_bmc_write_data(kcs_bmc, KCS_ZERO_DATA);
+	set_state(priv, WRITE_STATE);
+	kcs_bmc_write_data(priv->client.dev, KCS_ZERO_DATA);
 
-	cmd = kcs_bmc_read_data(kcs_bmc);
+	cmd = kcs_bmc_read_data(priv->client.dev);
 	switch (cmd) {
 	case KCS_CMD_WRITE_START:
-		kcs_bmc->phase = KCS_PHASE_WRITE_START;
-		kcs_bmc->error = KCS_NO_ERROR;
-		kcs_bmc->data_in_avail = false;
-		kcs_bmc->data_in_idx = 0;
+		priv->phase = KCS_PHASE_WRITE_START;
+		priv->error = KCS_NO_ERROR;
+		priv->data_in_avail = false;
+		priv->data_in_idx = 0;
 		break;
 
 	case KCS_CMD_WRITE_END:
-		if (kcs_bmc->phase != KCS_PHASE_WRITE_DATA) {
-			kcs_bmc_ipmi_force_abort(kcs_bmc);
+		if (priv->phase != KCS_PHASE_WRITE_DATA) {
+			kcs_bmc_ipmi_force_abort(priv);
 			break;
 		}
 
-		kcs_bmc->phase = KCS_PHASE_WRITE_END_CMD;
+		priv->phase = KCS_PHASE_WRITE_END_CMD;
 		break;
 
 	case KCS_CMD_GET_STATUS_ABORT:
-		if (kcs_bmc->error == KCS_NO_ERROR)
-			kcs_bmc->error = KCS_ABORTED_BY_COMMAND;
+		if (priv->error == KCS_NO_ERROR)
+			priv->error = KCS_ABORTED_BY_COMMAND;
 
-		kcs_bmc->phase = KCS_PHASE_ABORT_ERROR1;
-		kcs_bmc->data_in_avail = false;
-		kcs_bmc->data_in_idx = 0;
+		priv->phase = KCS_PHASE_ABORT_ERROR1;
+		priv->data_in_avail = false;
+		priv->data_in_idx = 0;
 		break;
 
 	default:
-		kcs_bmc_ipmi_force_abort(kcs_bmc);
-		kcs_bmc->error = KCS_ILLEGAL_CONTROL_CODE;
+		kcs_bmc_ipmi_force_abort(priv);
+		priv->error = KCS_ILLEGAL_CONTROL_CODE;
 		break;
 	}
 }
 
-static inline struct kcs_bmc *client_to_kcs_bmc(struct kcs_bmc_client *client)
+static inline struct kcs_bmc_ipmi *client_to_kcs_bmc_ipmi(struct kcs_bmc_client *client)
 {
-	return container_of(client, struct kcs_bmc, client);
+	return container_of(client, struct kcs_bmc_ipmi, client);
 }
 
 static irqreturn_t kcs_bmc_ipmi_event(struct kcs_bmc_client *client)
 {
-	struct kcs_bmc *kcs_bmc;
-	unsigned long flags;
+	struct kcs_bmc_ipmi *priv;
 	u8 status;
 	int ret;
 
-	kcs_bmc = client_to_kcs_bmc(client);
+	priv = client_to_kcs_bmc_ipmi(client);
+	if (!priv)
+		return IRQ_NONE;
 
-	spin_lock_irqsave(&kcs_bmc->lock, flags);
+	spin_lock(&priv->lock);
 
-	status = kcs_bmc_read_status(kcs_bmc);
+	status = kcs_bmc_read_status(client->dev);
 	if (status & KCS_STATUS_IBF) {
-		if (!kcs_bmc->running)
-			kcs_bmc_ipmi_force_abort(kcs_bmc);
-		else if (status & KCS_STATUS_CMD_DAT)
-			kcs_bmc_ipmi_handle_cmd(kcs_bmc);
+		if (status & KCS_STATUS_CMD_DAT)
+			kcs_bmc_ipmi_handle_cmd(priv);
 		else
-			kcs_bmc_ipmi_handle_data(kcs_bmc);
+			kcs_bmc_ipmi_handle_data(priv);
 
 		ret = IRQ_HANDLED;
 	} else {
 		ret = IRQ_NONE;
 	}
 
-	spin_unlock_irqrestore(&kcs_bmc->lock, flags);
+	spin_unlock(&priv->lock);
 
 	return ret;
 }
@@ -217,37 +290,29 @@ static const struct kcs_bmc_client_ops kcs_bmc_ipmi_client_ops = {
 	.event = kcs_bmc_ipmi_event,
 };
 
-static inline struct kcs_bmc *file_to_kcs_bmc(struct file *filp)
+static inline struct kcs_bmc_ipmi *to_kcs_bmc(struct file *filp)
 {
-	return container_of(filp->private_data, struct kcs_bmc, miscdev);
+	return container_of(filp->private_data, struct kcs_bmc_ipmi, miscdev);
 }
 
 static int kcs_bmc_ipmi_open(struct inode *inode, struct file *filp)
 {
-	struct kcs_bmc *kcs_bmc = file_to_kcs_bmc(filp);
-	int ret = 0;
+	struct kcs_bmc_ipmi *priv = to_kcs_bmc(filp);
 
-	spin_lock_irq(&kcs_bmc->lock);
-	if (!kcs_bmc->running)
-		kcs_bmc->running = 1;
-	else
-		ret = -EBUSY;
-	spin_unlock_irq(&kcs_bmc->lock);
-
-	return ret;
+	return kcs_bmc_enable_device(priv->client.dev, &priv->client);
 }
 
 static __poll_t kcs_bmc_ipmi_poll(struct file *filp, poll_table *wait)
 {
-	struct kcs_bmc *kcs_bmc = file_to_kcs_bmc(filp);
+	struct kcs_bmc_ipmi *priv = to_kcs_bmc(filp);
 	__poll_t mask = 0;
 
-	poll_wait(filp, &kcs_bmc->queue, wait);
+	poll_wait(filp, &priv->queue, wait);
 
-	spin_lock_irq(&kcs_bmc->lock);
-	if (kcs_bmc->data_in_avail)
+	spin_lock_irq(&priv->lock);
+	if (priv->data_in_avail)
 		mask |= EPOLLIN;
-	spin_unlock_irq(&kcs_bmc->lock);
+	spin_unlock_irq(&priv->lock);
 
 	return mask;
 }
@@ -255,24 +320,24 @@ static __poll_t kcs_bmc_ipmi_poll(struct file *filp, poll_table *wait)
 static ssize_t kcs_bmc_ipmi_read(struct file *filp, char __user *buf,
 			    size_t count, loff_t *ppos)
 {
-	struct kcs_bmc *kcs_bmc = file_to_kcs_bmc(filp);
+	struct kcs_bmc_ipmi *priv = to_kcs_bmc(filp);
 	bool data_avail;
 	size_t data_len;
 	ssize_t ret;
 
 	if (!(filp->f_flags & O_NONBLOCK))
-		wait_event_interruptible(kcs_bmc->queue,
-					 kcs_bmc->data_in_avail);
+		wait_event_interruptible(priv->queue,
+					 priv->data_in_avail);
 
-	mutex_lock(&kcs_bmc->mutex);
+	mutex_lock(&priv->mutex);
 
-	spin_lock_irq(&kcs_bmc->lock);
-	data_avail = kcs_bmc->data_in_avail;
+	spin_lock_irq(&priv->lock);
+	data_avail = priv->data_in_avail;
 	if (data_avail) {
-		data_len = kcs_bmc->data_in_idx;
-		memcpy(kcs_bmc->kbuffer, kcs_bmc->data_in, data_len);
+		data_len = priv->data_in_idx;
+		memcpy(priv->kbuffer, priv->data_in, data_len);
 	}
-	spin_unlock_irq(&kcs_bmc->lock);
+	spin_unlock_irq(&priv->lock);
 
 	if (!data_avail) {
 		ret = -EAGAIN;
@@ -281,35 +346,35 @@ static ssize_t kcs_bmc_ipmi_read(struct file *filp, char __user *buf,
 
 	if (count < data_len) {
 		pr_err("channel=%u with too large data : %zu\n",
-			kcs_bmc->channel, data_len);
+			priv->client.dev->channel, data_len);
 
-		spin_lock_irq(&kcs_bmc->lock);
-		kcs_bmc_ipmi_force_abort(kcs_bmc);
-		spin_unlock_irq(&kcs_bmc->lock);
+		spin_lock_irq(&priv->lock);
+		kcs_bmc_ipmi_force_abort(priv);
+		spin_unlock_irq(&priv->lock);
 
 		ret = -EOVERFLOW;
 		goto out_unlock;
 	}
 
-	if (copy_to_user(buf, kcs_bmc->kbuffer, data_len)) {
+	if (copy_to_user(buf, priv->kbuffer, data_len)) {
 		ret = -EFAULT;
 		goto out_unlock;
 	}
 
 	ret = data_len;
 
-	spin_lock_irq(&kcs_bmc->lock);
-	if (kcs_bmc->phase == KCS_PHASE_WRITE_DONE) {
-		kcs_bmc->phase = KCS_PHASE_WAIT_READ;
-		kcs_bmc->data_in_avail = false;
-		kcs_bmc->data_in_idx = 0;
+	spin_lock_irq(&priv->lock);
+	if (priv->phase == KCS_PHASE_WRITE_DONE) {
+		priv->phase = KCS_PHASE_WAIT_READ;
+		priv->data_in_avail = false;
+		priv->data_in_idx = 0;
 	} else {
 		ret = -EAGAIN;
 	}
-	spin_unlock_irq(&kcs_bmc->lock);
+	spin_unlock_irq(&priv->lock);
 
 out_unlock:
-	mutex_unlock(&kcs_bmc->mutex);
+	mutex_unlock(&priv->mutex);
 
 	return ret;
 }
@@ -317,35 +382,35 @@ static ssize_t kcs_bmc_ipmi_read(struct file *filp, char __user *buf,
 static ssize_t kcs_bmc_ipmi_write(struct file *filp, const char __user *buf,
 			     size_t count, loff_t *ppos)
 {
-	struct kcs_bmc *kcs_bmc = file_to_kcs_bmc(filp);
+	struct kcs_bmc_ipmi *priv = to_kcs_bmc(filp);
 	ssize_t ret;
 
 	/* a minimum response size '3' : netfn + cmd + ccode */
 	if (count < 3 || count > KCS_MSG_BUFSIZ)
 		return -EINVAL;
 
-	mutex_lock(&kcs_bmc->mutex);
+	mutex_lock(&priv->mutex);
 
-	if (copy_from_user(kcs_bmc->kbuffer, buf, count)) {
+	if (copy_from_user(priv->kbuffer, buf, count)) {
 		ret = -EFAULT;
 		goto out_unlock;
 	}
 
-	spin_lock_irq(&kcs_bmc->lock);
-	if (kcs_bmc->phase == KCS_PHASE_WAIT_READ) {
-		kcs_bmc->phase = KCS_PHASE_READ;
-		kcs_bmc->data_out_idx = 1;
-		kcs_bmc->data_out_len = count;
-		memcpy(kcs_bmc->data_out, kcs_bmc->kbuffer, count);
-		kcs_bmc_write_data(kcs_bmc, kcs_bmc->data_out[0]);
+	spin_lock_irq(&priv->lock);
+	if (priv->phase == KCS_PHASE_WAIT_READ) {
+		priv->phase = KCS_PHASE_READ;
+		priv->data_out_idx = 1;
+		priv->data_out_len = count;
+		memcpy(priv->data_out, priv->kbuffer, count);
+		kcs_bmc_write_data(priv->client.dev, priv->data_out[0]);
 		ret = count;
 	} else {
 		ret = -EINVAL;
 	}
-	spin_unlock_irq(&kcs_bmc->lock);
+	spin_unlock_irq(&priv->lock);
 
 out_unlock:
-	mutex_unlock(&kcs_bmc->mutex);
+	mutex_unlock(&priv->mutex);
 
 	return ret;
 }
@@ -353,22 +418,22 @@ static ssize_t kcs_bmc_ipmi_write(struct file *filp, const char __user *buf,
 static long kcs_bmc_ipmi_ioctl(struct file *filp, unsigned int cmd,
 			  unsigned long arg)
 {
-	struct kcs_bmc *kcs_bmc = file_to_kcs_bmc(filp);
+	struct kcs_bmc_ipmi *priv = to_kcs_bmc(filp);
 	long ret = 0;
 
-	spin_lock_irq(&kcs_bmc->lock);
+	spin_lock_irq(&priv->lock);
 
 	switch (cmd) {
 	case IPMI_BMC_IOCTL_SET_SMS_ATN:
-		kcs_bmc_update_status(kcs_bmc, KCS_STATUS_SMS_ATN, KCS_STATUS_SMS_ATN);
+		kcs_bmc_update_status(priv->client.dev, KCS_STATUS_SMS_ATN, KCS_STATUS_SMS_ATN);
 		break;
 
 	case IPMI_BMC_IOCTL_CLEAR_SMS_ATN:
-		kcs_bmc_update_status(kcs_bmc, KCS_STATUS_SMS_ATN, 0);
+		kcs_bmc_update_status(priv->client.dev, KCS_STATUS_SMS_ATN, 0);
 		break;
 
 	case IPMI_BMC_IOCTL_FORCE_ABORT:
-		kcs_bmc_ipmi_force_abort(kcs_bmc);
+		kcs_bmc_ipmi_force_abort(priv);
 		break;
 
 	default:
@@ -376,19 +441,17 @@ static long kcs_bmc_ipmi_ioctl(struct file *filp, unsigned int cmd,
 		break;
 	}
 
-	spin_unlock_irq(&kcs_bmc->lock);
+	spin_unlock_irq(&priv->lock);
 
 	return ret;
 }
 
 static int kcs_bmc_ipmi_release(struct inode *inode, struct file *filp)
 {
-	struct kcs_bmc *kcs_bmc = file_to_kcs_bmc(filp);
+	struct kcs_bmc_ipmi *priv = to_kcs_bmc(filp);
 
-	spin_lock_irq(&kcs_bmc->lock);
-	kcs_bmc->running = 0;
-	kcs_bmc_ipmi_force_abort(kcs_bmc);
-	spin_unlock_irq(&kcs_bmc->lock);
+	kcs_bmc_ipmi_force_abort(priv);
+	kcs_bmc_disable_device(priv->client.dev, &priv->client);
 
 	return 0;
 }
@@ -403,56 +466,78 @@ static const struct file_operations kcs_bmc_ipmi_fops = {
 	.unlocked_ioctl = kcs_bmc_ipmi_ioctl,
 };
 
-int kcs_bmc_ipmi_add_device(struct kcs_bmc *kcs_bmc);
-int kcs_bmc_ipmi_add_device(struct kcs_bmc *kcs_bmc)
+static DEFINE_SPINLOCK(kcs_bmc_ipmi_instances_lock);
+static LIST_HEAD(kcs_bmc_ipmi_instances);
+
+int kcs_bmc_ipmi_add_device(struct kcs_bmc_device *kcs_bmc);
+int kcs_bmc_ipmi_add_device(struct kcs_bmc_device *kcs_bmc)
 {
+	struct kcs_bmc_ipmi *priv;
 	int rc;
 
-	spin_lock_init(&kcs_bmc->lock);
-	mutex_init(&kcs_bmc->mutex);
-	init_waitqueue_head(&kcs_bmc->queue);
-
-	kcs_bmc->client.dev = kcs_bmc;
-	kcs_bmc->client.ops = &kcs_bmc_ipmi_client_ops;
-	kcs_bmc->data_in = devm_kmalloc(kcs_bmc->dev, KCS_MSG_BUFSIZ, GFP_KERNEL);
-	kcs_bmc->data_out = devm_kmalloc(kcs_bmc->dev, KCS_MSG_BUFSIZ, GFP_KERNEL);
-	kcs_bmc->kbuffer = devm_kmalloc(kcs_bmc->dev, KCS_MSG_BUFSIZ, GFP_KERNEL);
-
-	kcs_bmc->miscdev.minor = MISC_DYNAMIC_MINOR;
-	kcs_bmc->miscdev.name = devm_kasprintf(kcs_bmc->dev, GFP_KERNEL, "%s%u",
-					       DEVICE_NAME, kcs_bmc->channel);
-	if (!kcs_bmc->data_in || !kcs_bmc->data_out || !kcs_bmc->kbuffer ||
-	    !kcs_bmc->miscdev.name)
+	priv = devm_kzalloc(kcs_bmc->dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
 		return -ENOMEM;
 
-	kcs_bmc->miscdev.fops = &kcs_bmc_ipmi_fops;
+	spin_lock_init(&priv->lock);
+	mutex_init(&priv->mutex);
 
-	rc = misc_register(&kcs_bmc->miscdev);
+	init_waitqueue_head(&priv->queue);
+
+	priv->client.dev = kcs_bmc;
+	priv->client.ops = &kcs_bmc_ipmi_client_ops;
+	priv->data_in = devm_kmalloc(kcs_bmc->dev, KCS_MSG_BUFSIZ, GFP_KERNEL);
+	priv->data_out = devm_kmalloc(kcs_bmc->dev, KCS_MSG_BUFSIZ, GFP_KERNEL);
+	priv->kbuffer = devm_kmalloc(kcs_bmc->dev, KCS_MSG_BUFSIZ, GFP_KERNEL);
+
+	priv->miscdev.minor = MISC_DYNAMIC_MINOR;
+	priv->miscdev.name = devm_kasprintf(kcs_bmc->dev, GFP_KERNEL, "%s%u", DEVICE_NAME,
+					   kcs_bmc->channel);
+	if (!priv->data_in || !priv->data_out || !priv->kbuffer || !priv->miscdev.name)
+		return -EINVAL;
+
+	priv->miscdev.fops = &kcs_bmc_ipmi_fops;
+
+	rc = misc_register(&priv->miscdev);
 	if (rc) {
 		dev_err(kcs_bmc->dev, "Unable to register device: %d\n", rc);
 		return rc;
 	}
 
+	spin_lock_irq(&kcs_bmc_ipmi_instances_lock);
+	list_add(&priv->entry, &kcs_bmc_ipmi_instances);
+	spin_unlock_irq(&kcs_bmc_ipmi_instances_lock);
+
 	dev_info(kcs_bmc->dev, "Initialised IPMI client for channel %d", kcs_bmc->channel);
 
 	return 0;
 }
 EXPORT_SYMBOL(kcs_bmc_ipmi_add_device);
 
-int kcs_bmc_ipmi_remove_device(struct kcs_bmc *kcs_bmc);
-int kcs_bmc_ipmi_remove_device(struct kcs_bmc *kcs_bmc)
+int kcs_bmc_ipmi_remove_device(struct kcs_bmc_device *kcs_bmc);
+int kcs_bmc_ipmi_remove_device(struct kcs_bmc_device *kcs_bmc)
 {
-	misc_deregister(&kcs_bmc->miscdev);
+	struct kcs_bmc_ipmi *priv = NULL, *pos;
 
-	spin_lock_irq(&kcs_bmc->lock);
-	kcs_bmc->running = 0;
-	kcs_bmc_ipmi_force_abort(kcs_bmc);
-	spin_unlock_irq(&kcs_bmc->lock);
+	spin_lock_irq(&kcs_bmc_ipmi_instances_lock);
+	list_for_each_entry(pos, &kcs_bmc_ipmi_instances, entry) {
+		if (pos->client.dev == kcs_bmc) {
+			priv = pos;
+			list_del(&pos->entry);
+			break;
+		}
+	}
+	spin_unlock_irq(&kcs_bmc_ipmi_instances_lock);
 
-	devm_kfree(kcs_bmc->dev, kcs_bmc->kbuffer);
-	devm_kfree(kcs_bmc->dev, kcs_bmc->data_out);
-	devm_kfree(kcs_bmc->dev, kcs_bmc->data_in);
-	devm_kfree(kcs_bmc->dev, kcs_bmc);
+	if (!priv)
+		return -ENODEV;
+
+	misc_deregister(&priv->miscdev);
+	kcs_bmc_disable_device(priv->client.dev, &priv->client);
+	devm_kfree(kcs_bmc->dev, priv->kbuffer);
+	devm_kfree(kcs_bmc->dev, priv->data_out);
+	devm_kfree(kcs_bmc->dev, priv->data_in);
+	devm_kfree(kcs_bmc->dev, priv);
 
 	return 0;
 }
@@ -460,4 +545,5 @@ EXPORT_SYMBOL(kcs_bmc_ipmi_remove_device);
 
 MODULE_LICENSE("GPL v2");
 MODULE_AUTHOR("Haiyue Wang <haiyue.wang@linux.intel.com>");
+MODULE_AUTHOR("Andrew Jeffery <andrew@aj.id.au>");
 MODULE_DESCRIPTION("KCS BMC to handle the IPMI request from system software");
diff --git a/drivers/char/ipmi/kcs_bmc_client.h b/drivers/char/ipmi/kcs_bmc_client.h
index dad8774aebce..a32fdc4a7707 100644
--- a/drivers/char/ipmi/kcs_bmc_client.h
+++ b/drivers/char/ipmi/kcs_bmc_client.h
@@ -6,22 +6,24 @@
 
 #include <linux/irqreturn.h>
 
-struct kcs_bmc;
-struct kcs_bmc_client_ops;
-
-struct kcs_bmc_client {
-	const struct kcs_bmc_client_ops *ops;
-
-	struct kcs_bmc *dev;
-};
+#include "kcs_bmc.h"
 
 struct kcs_bmc_client_ops {
 	irqreturn_t (*event)(struct kcs_bmc_client *client);
 };
 
-u8 kcs_bmc_read_data(struct kcs_bmc *kcs_bmc);
-void kcs_bmc_write_data(struct kcs_bmc *kcs_bmc, u8 data);
-u8 kcs_bmc_read_status(struct kcs_bmc *kcs_bmc);
-void kcs_bmc_write_status(struct kcs_bmc *kcs_bmc, u8 data);
-void kcs_bmc_update_status(struct kcs_bmc *kcs_bmc, u8 mask, u8 val);
+struct kcs_bmc_client {
+	const struct kcs_bmc_client_ops *ops;
+
+	struct kcs_bmc_device *dev;
+};
+
+int kcs_bmc_enable_device(struct kcs_bmc_device *kcs_bmc, struct kcs_bmc_client *client);
+void kcs_bmc_disable_device(struct kcs_bmc_device *kcs_bmc, struct kcs_bmc_client *client);
+
+u8 kcs_bmc_read_data(struct kcs_bmc_device *kcs_bmc);
+void kcs_bmc_write_data(struct kcs_bmc_device *kcs_bmc, u8 data);
+u8 kcs_bmc_read_status(struct kcs_bmc_device *kcs_bmc);
+void kcs_bmc_write_status(struct kcs_bmc_device *kcs_bmc, u8 data);
+void kcs_bmc_update_status(struct kcs_bmc_device *kcs_bmc, u8 mask, u8 val);
 #endif
diff --git a/drivers/char/ipmi/kcs_bmc_device.h b/drivers/char/ipmi/kcs_bmc_device.h
index dd8bf1307ad2..c9a4237bbf40 100644
--- a/drivers/char/ipmi/kcs_bmc_device.h
+++ b/drivers/char/ipmi/kcs_bmc_device.h
@@ -4,16 +4,18 @@
 #ifndef __KCS_BMC_DEVICE_H__
 #define __KCS_BMC_DEVICE_H__
 
+#include <linux/irqreturn.h>
+
 #include "kcs_bmc.h"
 
 struct kcs_bmc_device_ops {
-	u8 (*io_inputb)(struct kcs_bmc *kcs_bmc, u32 reg);
-	void (*io_outputb)(struct kcs_bmc *kcs_bmc, u32 reg, u8 b);
-	void (*io_updateb)(struct kcs_bmc *kcs_bmc, u32 reg, u8 mask, u8 b);
+	u8 (*io_inputb)(struct kcs_bmc_device *kcs_bmc, u32 reg);
+	void (*io_outputb)(struct kcs_bmc_device *kcs_bmc, u32 reg, u8 b);
+	void (*io_updateb)(struct kcs_bmc_device *kcs_bmc, u32 reg, u8 mask, u8 b);
 };
 
-irqreturn_t kcs_bmc_handle_event(struct kcs_bmc *kcs_bmc);
-int kcs_bmc_add_device(struct kcs_bmc *kcs_bmc);
-void kcs_bmc_remove_device(struct kcs_bmc *kcs_bmc);
+irqreturn_t kcs_bmc_handle_event(struct kcs_bmc_device *kcs_bmc);
+int kcs_bmc_add_device(struct kcs_bmc_device *kcs_bmc);
+void kcs_bmc_remove_device(struct kcs_bmc_device *kcs_bmc);
 
 #endif
diff --git a/drivers/char/ipmi/kcs_bmc_npcm7xx.c b/drivers/char/ipmi/kcs_bmc_npcm7xx.c
index ebb691af28c5..3b96486c25c3 100644
--- a/drivers/char/ipmi/kcs_bmc_npcm7xx.c
+++ b/drivers/char/ipmi/kcs_bmc_npcm7xx.c
@@ -65,7 +65,7 @@ struct npcm7xx_kcs_reg {
 };
 
 struct npcm7xx_kcs_bmc {
-	struct kcs_bmc kcs_bmc;
+	struct kcs_bmc_device kcs_bmc;
 
 	struct regmap *map;
 
@@ -78,12 +78,12 @@ static const struct npcm7xx_kcs_reg npcm7xx_kcs_reg_tbl[KCS_CHANNEL_MAX] = {
 	{ .sts = KCS3ST, .dob = KCS3DO, .dib = KCS3DI, .ctl = KCS3CTL, .ie = KCS3IE },
 };
 
-static inline struct npcm7xx_kcs_bmc *to_npcm7xx_kcs_bmc(struct kcs_bmc *kcs_bmc)
+static inline struct npcm7xx_kcs_bmc *to_npcm7xx_kcs_bmc(struct kcs_bmc_device *kcs_bmc)
 {
 	return container_of(kcs_bmc, struct npcm7xx_kcs_bmc, kcs_bmc);
 }
 
-static u8 npcm7xx_kcs_inb(struct kcs_bmc *kcs_bmc, u32 reg)
+static u8 npcm7xx_kcs_inb(struct kcs_bmc_device *kcs_bmc, u32 reg)
 {
 	struct npcm7xx_kcs_bmc *priv = to_npcm7xx_kcs_bmc(kcs_bmc);
 	u32 val = 0;
@@ -95,7 +95,7 @@ static u8 npcm7xx_kcs_inb(struct kcs_bmc *kcs_bmc, u32 reg)
 	return rc == 0 ? (u8)val : 0;
 }
 
-static void npcm7xx_kcs_outb(struct kcs_bmc *kcs_bmc, u32 reg, u8 data)
+static void npcm7xx_kcs_outb(struct kcs_bmc_device *kcs_bmc, u32 reg, u8 data)
 {
 	struct npcm7xx_kcs_bmc *priv = to_npcm7xx_kcs_bmc(kcs_bmc);
 	int rc;
@@ -104,7 +104,7 @@ static void npcm7xx_kcs_outb(struct kcs_bmc *kcs_bmc, u32 reg, u8 data)
 	WARN(rc != 0, "regmap_write() failed: %d\n", rc);
 }
 
-static void npcm7xx_kcs_updateb(struct kcs_bmc *kcs_bmc, u32 reg, u8 mask, u8 data)
+static void npcm7xx_kcs_updateb(struct kcs_bmc_device *kcs_bmc, u32 reg, u8 mask, u8 data)
 {
 	struct npcm7xx_kcs_bmc *priv = to_npcm7xx_kcs_bmc(kcs_bmc);
 	int rc;
@@ -113,7 +113,7 @@ static void npcm7xx_kcs_updateb(struct kcs_bmc *kcs_bmc, u32 reg, u8 mask, u8 da
 	WARN(rc != 0, "regmap_update_bits() failed: %d\n", rc);
 }
 
-static void npcm7xx_kcs_enable_channel(struct kcs_bmc *kcs_bmc, bool enable)
+static void npcm7xx_kcs_enable_channel(struct kcs_bmc_device *kcs_bmc, bool enable)
 {
 	struct npcm7xx_kcs_bmc *priv = to_npcm7xx_kcs_bmc(kcs_bmc);
 
@@ -126,12 +126,12 @@ static void npcm7xx_kcs_enable_channel(struct kcs_bmc *kcs_bmc, bool enable)
 
 static irqreturn_t npcm7xx_kcs_irq(int irq, void *arg)
 {
-	struct kcs_bmc *kcs_bmc = arg;
+	struct kcs_bmc_device *kcs_bmc = arg;
 
 	return kcs_bmc_handle_event(kcs_bmc);
 }
 
-static int npcm7xx_kcs_config_irq(struct kcs_bmc *kcs_bmc,
+static int npcm7xx_kcs_config_irq(struct kcs_bmc_device *kcs_bmc,
 				  struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
@@ -155,7 +155,7 @@ static int npcm7xx_kcs_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct npcm7xx_kcs_bmc *priv;
-	struct kcs_bmc *kcs_bmc;
+	struct kcs_bmc_device *kcs_bmc;
 	u32 chan;
 	int rc;
 
@@ -207,7 +207,7 @@ static int npcm7xx_kcs_probe(struct platform_device *pdev)
 static int npcm7xx_kcs_remove(struct platform_device *pdev)
 {
 	struct npcm7xx_kcs_bmc *priv = platform_get_drvdata(pdev);
-	struct kcs_bmc *kcs_bmc = &priv->kcs_bmc;
+	struct kcs_bmc_device *kcs_bmc = &priv->kcs_bmc;
 
 	kcs_bmc_remove_device(kcs_bmc);
 
-- 
2.30.2


^ permalink raw reply related	[flat|nested] 23+ messages in thread

* [PATCH v4 08/16] ipmi: kcs_bmc: Decouple the IPMI chardev from the core
  2021-06-08 10:47 [PATCH v4 00/16] ipmi: Allow raw access to KCS devices Andrew Jeffery
                   ` (6 preceding siblings ...)
  2021-06-08 10:47 ` [PATCH v4 07/16] ipmi: kcs_bmc: Strip private client data from struct kcs_bmc Andrew Jeffery
@ 2021-06-08 10:47 ` Andrew Jeffery
  2021-06-18 23:26   ` Zev Weiss
  2021-06-08 10:47 ` [PATCH v4 09/16] ipmi: kcs_bmc: Allow clients to control KCS IRQ state Andrew Jeffery
                   ` (8 subsequent siblings)
  16 siblings, 1 reply; 23+ messages in thread
From: Andrew Jeffery @ 2021-06-08 10:47 UTC (permalink / raw)
  To: openipmi-developer, openbmc, minyard
  Cc: devicetree, tmaimon77, linux-aspeed, avifishman70, venture,
	linux-kernel, tali.perry1, robh+dt, chiawei_wang,
	linux-arm-kernel, benjaminfair, arnd, zweiss, joel, KWLIU

Now that we have untangled the data-structures, split the userspace
interface out into its own module. Userspace interfaces and drivers are
registered to the KCS BMC core to support arbitrary binding of either.

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
---
 drivers/char/ipmi/Kconfig             | 13 +++++
 drivers/char/ipmi/Makefile            |  3 +-
 drivers/char/ipmi/kcs_bmc.c           | 80 +++++++++++++++++++++++++--
 drivers/char/ipmi/kcs_bmc_cdev_ipmi.c | 31 +++++++++--
 drivers/char/ipmi/kcs_bmc_client.h    | 14 +++++
 5 files changed, 128 insertions(+), 13 deletions(-)

diff --git a/drivers/char/ipmi/Kconfig b/drivers/char/ipmi/Kconfig
index 07847d9a459a..bc5f81899b62 100644
--- a/drivers/char/ipmi/Kconfig
+++ b/drivers/char/ipmi/Kconfig
@@ -124,6 +124,19 @@ config NPCM7XX_KCS_IPMI_BMC
 	  This support is also available as a module.  If so, the module
 	  will be called kcs_bmc_npcm7xx.
 
+config IPMI_KCS_BMC_CDEV_IPMI
+	depends on IPMI_KCS_BMC
+	tristate "IPMI character device interface for BMC KCS devices"
+	help
+	  Provides a BMC-side character device implementing IPMI
+	  semantics for KCS IPMI devices.
+
+	  Say YES if you wish to expose KCS devices on the BMC for IPMI
+	  purposes.
+
+	  This support is also available as a module. The module will be
+	  called kcs_bmc_cdev_ipmi.
+
 config ASPEED_BT_IPMI_BMC
 	depends on ARCH_ASPEED || COMPILE_TEST
 	depends on REGMAP && REGMAP_MMIO && MFD_SYSCON
diff --git a/drivers/char/ipmi/Makefile b/drivers/char/ipmi/Makefile
index a302bc865370..fcfa676afddb 100644
--- a/drivers/char/ipmi/Makefile
+++ b/drivers/char/ipmi/Makefile
@@ -22,7 +22,8 @@ obj-$(CONFIG_IPMI_SSIF) += ipmi_ssif.o
 obj-$(CONFIG_IPMI_POWERNV) += ipmi_powernv.o
 obj-$(CONFIG_IPMI_WATCHDOG) += ipmi_watchdog.o
 obj-$(CONFIG_IPMI_POWEROFF) += ipmi_poweroff.o
-obj-$(CONFIG_IPMI_KCS_BMC) += kcs_bmc.o kcs_bmc_cdev_ipmi.o
+obj-$(CONFIG_IPMI_KCS_BMC) += kcs_bmc.o
+obj-$(CONFIG_IPMI_KCS_BMC_CDEV_IPMI) += kcs_bmc_cdev_ipmi.o
 obj-$(CONFIG_ASPEED_BT_IPMI_BMC) += bt-bmc.o
 obj-$(CONFIG_ASPEED_KCS_IPMI_BMC) += kcs_bmc_aspeed.o
 obj-$(CONFIG_NPCM7XX_KCS_IPMI_BMC) += kcs_bmc_npcm7xx.o
diff --git a/drivers/char/ipmi/kcs_bmc.c b/drivers/char/ipmi/kcs_bmc.c
index 2ec934f0dba3..9860c7b75157 100644
--- a/drivers/char/ipmi/kcs_bmc.c
+++ b/drivers/char/ipmi/kcs_bmc.c
@@ -5,7 +5,9 @@
  */
 
 #include <linux/device.h>
+#include <linux/list.h>
 #include <linux/module.h>
+#include <linux/mutex.h>
 
 #include "kcs_bmc.h"
 
@@ -13,6 +15,11 @@
 #include "kcs_bmc_device.h"
 #include "kcs_bmc_client.h"
 
+/* Record registered devices and drivers */
+static DEFINE_MUTEX(kcs_bmc_lock);
+static LIST_HEAD(kcs_bmc_devices);
+static LIST_HEAD(kcs_bmc_drivers);
+
 /* Consumer data access */
 
 u8 kcs_bmc_read_data(struct kcs_bmc_device *kcs_bmc)
@@ -98,22 +105,83 @@ void kcs_bmc_disable_device(struct kcs_bmc_device *kcs_bmc, struct kcs_bmc_clien
 }
 EXPORT_SYMBOL(kcs_bmc_disable_device);
 
-int kcs_bmc_ipmi_add_device(struct kcs_bmc_device *kcs_bmc);
 int kcs_bmc_add_device(struct kcs_bmc_device *kcs_bmc)
 {
-	return kcs_bmc_ipmi_add_device(kcs_bmc);
+	struct kcs_bmc_driver *drv;
+	int error = 0;
+	int rc;
+
+	spin_lock_init(&kcs_bmc->lock);
+	kcs_bmc->client = NULL;
+
+	mutex_lock(&kcs_bmc_lock);
+	list_add(&kcs_bmc->entry, &kcs_bmc_devices);
+	list_for_each_entry(drv, &kcs_bmc_drivers, entry) {
+		rc = drv->ops->add_device(kcs_bmc);
+		if (!rc)
+			continue;
+
+		dev_err(kcs_bmc->dev, "Failed to add chardev for KCS channel %d: %d",
+			kcs_bmc->channel, rc);
+		error = rc;
+	}
+	mutex_unlock(&kcs_bmc_lock);
+
+	return error;
 }
 EXPORT_SYMBOL(kcs_bmc_add_device);
 
-int kcs_bmc_ipmi_remove_device(struct kcs_bmc_device *kcs_bmc);
 void kcs_bmc_remove_device(struct kcs_bmc_device *kcs_bmc)
 {
-	if (kcs_bmc_ipmi_remove_device(kcs_bmc))
-		pr_warn("Failed to remove device for KCS channel %d\n",
-			kcs_bmc->channel);
+	struct kcs_bmc_driver *drv;
+	int rc;
+
+	mutex_lock(&kcs_bmc_lock);
+	list_del(&kcs_bmc->entry);
+	list_for_each_entry(drv, &kcs_bmc_drivers, entry) {
+		rc = drv->ops->remove_device(kcs_bmc);
+		if (rc)
+			dev_err(kcs_bmc->dev, "Failed to remove chardev for KCS channel %d: %d",
+				kcs_bmc->channel, rc);
+	}
+	mutex_unlock(&kcs_bmc_lock);
 }
 EXPORT_SYMBOL(kcs_bmc_remove_device);
 
+void kcs_bmc_register_driver(struct kcs_bmc_driver *drv)
+{
+	struct kcs_bmc_device *kcs_bmc;
+	int rc;
+
+	mutex_lock(&kcs_bmc_lock);
+	list_add(&drv->entry, &kcs_bmc_drivers);
+	list_for_each_entry(kcs_bmc, &kcs_bmc_devices, entry) {
+		rc = drv->ops->add_device(kcs_bmc);
+		if (rc)
+			dev_err(kcs_bmc->dev, "Failed to add driver for KCS channel %d: %d",
+				kcs_bmc->channel, rc);
+	}
+	mutex_unlock(&kcs_bmc_lock);
+}
+EXPORT_SYMBOL(kcs_bmc_register_driver);
+
+void kcs_bmc_unregister_driver(struct kcs_bmc_driver *drv)
+{
+	struct kcs_bmc_device *kcs_bmc;
+	int rc;
+
+	mutex_lock(&kcs_bmc_lock);
+	list_del(&drv->entry);
+	list_for_each_entry(kcs_bmc, &kcs_bmc_devices, entry) {
+		rc = drv->ops->remove_device(kcs_bmc);
+		if (rc)
+			dev_err(kcs_bmc->dev, "Failed to remove driver for KCS channel %d: %d",
+				kcs_bmc->channel, rc);
+	}
+	mutex_unlock(&kcs_bmc_lock);
+}
+EXPORT_SYMBOL(kcs_bmc_unregister_driver);
+
 MODULE_LICENSE("GPL v2");
 MODULE_AUTHOR("Haiyue Wang <haiyue.wang@linux.intel.com>");
 MODULE_AUTHOR("Andrew Jeffery <andrew@aj.id.au>");
diff --git a/drivers/char/ipmi/kcs_bmc_cdev_ipmi.c b/drivers/char/ipmi/kcs_bmc_cdev_ipmi.c
index 865d8b93f3b7..486834a962c3 100644
--- a/drivers/char/ipmi/kcs_bmc_cdev_ipmi.c
+++ b/drivers/char/ipmi/kcs_bmc_cdev_ipmi.c
@@ -469,8 +469,7 @@ static const struct file_operations kcs_bmc_ipmi_fops = {
 static DEFINE_SPINLOCK(kcs_bmc_ipmi_instances_lock);
 static LIST_HEAD(kcs_bmc_ipmi_instances);
 
-int kcs_bmc_ipmi_add_device(struct kcs_bmc_device *kcs_bmc);
-int kcs_bmc_ipmi_add_device(struct kcs_bmc_device *kcs_bmc)
+static int kcs_bmc_ipmi_add_device(struct kcs_bmc_device *kcs_bmc)
 {
 	struct kcs_bmc_ipmi *priv;
 	int rc;
@@ -512,10 +511,8 @@ int kcs_bmc_ipmi_add_device(struct kcs_bmc_device *kcs_bmc)
 
 	return 0;
 }
-EXPORT_SYMBOL(kcs_bmc_ipmi_add_device);
 
-int kcs_bmc_ipmi_remove_device(struct kcs_bmc_device *kcs_bmc);
-int kcs_bmc_ipmi_remove_device(struct kcs_bmc_device *kcs_bmc)
+static int kcs_bmc_ipmi_remove_device(struct kcs_bmc_device *kcs_bmc)
 {
 	struct kcs_bmc_ipmi *priv = NULL, *pos;
 
@@ -541,7 +538,29 @@ int kcs_bmc_ipmi_remove_device(struct kcs_bmc_device *kcs_bmc)
 
 	return 0;
 }
-EXPORT_SYMBOL(kcs_bmc_ipmi_remove_device);
+
+static const struct kcs_bmc_driver_ops kcs_bmc_ipmi_driver_ops = {
+	.add_device = kcs_bmc_ipmi_add_device,
+	.remove_device = kcs_bmc_ipmi_remove_device,
+};
+
+static struct kcs_bmc_driver kcs_bmc_ipmi_driver = {
+	.ops = &kcs_bmc_ipmi_driver_ops,
+};
+
+static int kcs_bmc_ipmi_init(void)
+{
+	kcs_bmc_register_driver(&kcs_bmc_ipmi_driver);
+
+	return 0;
+}
+module_init(kcs_bmc_ipmi_init);
+
+static void kcs_bmc_ipmi_exit(void)
+{
+	kcs_bmc_unregister_driver(&kcs_bmc_ipmi_driver);
+}
+module_exit(kcs_bmc_ipmi_exit);
 
 MODULE_LICENSE("GPL v2");
 MODULE_AUTHOR("Haiyue Wang <haiyue.wang@linux.intel.com>");
diff --git a/drivers/char/ipmi/kcs_bmc_client.h b/drivers/char/ipmi/kcs_bmc_client.h
index a32fdc4a7707..814ad8e052ef 100644
--- a/drivers/char/ipmi/kcs_bmc_client.h
+++ b/drivers/char/ipmi/kcs_bmc_client.h
@@ -8,6 +8,17 @@
 
 #include "kcs_bmc.h"
 
+struct kcs_bmc_driver_ops {
+	int (*add_device)(struct kcs_bmc_device *kcs_bmc);
+	int (*remove_device)(struct kcs_bmc_device *kcs_bmc);
+};
+
+struct kcs_bmc_driver {
+	struct list_head entry;
+
+	const struct kcs_bmc_driver_ops *ops;
+};
+
 struct kcs_bmc_client_ops {
 	irqreturn_t (*event)(struct kcs_bmc_client *client);
 };
@@ -18,6 +29,9 @@ struct kcs_bmc_client {
 	struct kcs_bmc_device *dev;
 };
 
+void kcs_bmc_register_driver(struct kcs_bmc_driver *drv);
+void kcs_bmc_unregister_driver(struct kcs_bmc_driver *drv);
+
 int kcs_bmc_enable_device(struct kcs_bmc_device *kcs_bmc, struct kcs_bmc_client *client);
 void kcs_bmc_disable_device(struct kcs_bmc_device *kcs_bmc, struct kcs_bmc_client *client);
 
-- 
2.30.2


^ permalink raw reply related	[flat|nested] 23+ messages in thread

* [PATCH v4 09/16] ipmi: kcs_bmc: Allow clients to control KCS IRQ state
  2021-06-08 10:47 [PATCH v4 00/16] ipmi: Allow raw access to KCS devices Andrew Jeffery
                   ` (7 preceding siblings ...)
  2021-06-08 10:47 ` [PATCH v4 08/16] ipmi: kcs_bmc: Decouple the IPMI chardev from the core Andrew Jeffery
@ 2021-06-08 10:47 ` Andrew Jeffery
  2021-06-08 10:47 ` [PATCH v4 10/16] ipmi: kcs_bmc: Enable IBF on open Andrew Jeffery
                   ` (7 subsequent siblings)
  16 siblings, 0 replies; 23+ messages in thread
From: Andrew Jeffery @ 2021-06-08 10:47 UTC (permalink / raw)
  To: openipmi-developer, openbmc, minyard
  Cc: devicetree, tmaimon77, linux-aspeed, avifishman70, venture,
	linux-kernel, tali.perry1, robh+dt, chiawei_wang,
	linux-arm-kernel, benjaminfair, arnd, zweiss, joel, KWLIU

Add a mechanism for controlling whether the client associated with a
KCS device will receive Input Buffer Full (IBF) and Output Buffer Empty
(OBE) events. This enables an abstract implementation of poll() for KCS
devices.

A wart in the implementation is that the ASPEED KCS devices don't
support an OBE interrupt for the BMC. Instead we pretend it has one by
polling the status register waiting for the Output Buffer Full (OBF) bit
to clear, and generating an event when OBE is observed.

Cc: CS20 KWLiu <KWLIU@nuvoton.com>
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Reviewed-by: Zev Weiss <zweiss@equinix.com>
---
 drivers/char/ipmi/kcs_bmc.c         |   6 ++
 drivers/char/ipmi/kcs_bmc.h         |   3 +
 drivers/char/ipmi/kcs_bmc_aspeed.c  | 150 ++++++++++++++++++----------
 drivers/char/ipmi/kcs_bmc_client.h  |   2 +
 drivers/char/ipmi/kcs_bmc_device.h  |   1 +
 drivers/char/ipmi/kcs_bmc_npcm7xx.c |  26 ++++-
 6 files changed, 131 insertions(+), 57 deletions(-)

diff --git a/drivers/char/ipmi/kcs_bmc.c b/drivers/char/ipmi/kcs_bmc.c
index 9860c7b75157..91eb43746cef 100644
--- a/drivers/char/ipmi/kcs_bmc.c
+++ b/drivers/char/ipmi/kcs_bmc.c
@@ -182,6 +182,12 @@ void kcs_bmc_unregister_driver(struct kcs_bmc_driver *drv)
 }
 EXPORT_SYMBOL(kcs_bmc_unregister_driver);
 
+void kcs_bmc_update_event_mask(struct kcs_bmc_device *kcs_bmc, u8 mask, u8 events)
+{
+	kcs_bmc->ops->irq_mask_update(kcs_bmc, mask, events);
+}
+EXPORT_SYMBOL(kcs_bmc_update_event_mask);
+
 MODULE_LICENSE("GPL v2");
 MODULE_AUTHOR("Haiyue Wang <haiyue.wang@linux.intel.com>");
 MODULE_AUTHOR("Andrew Jeffery <andrew@aj.id.au>");
diff --git a/drivers/char/ipmi/kcs_bmc.h b/drivers/char/ipmi/kcs_bmc.h
index 3f0cce315b4f..fa408b802c79 100644
--- a/drivers/char/ipmi/kcs_bmc.h
+++ b/drivers/char/ipmi/kcs_bmc.h
@@ -8,6 +8,9 @@
 
 #include <linux/list.h>
 
+#define KCS_BMC_EVENT_TYPE_OBE	BIT(0)
+#define KCS_BMC_EVENT_TYPE_IBF	BIT(1)
+
 #define KCS_BMC_STR_OBF		BIT(0)
 #define KCS_BMC_STR_IBF		BIT(1)
 #define KCS_BMC_STR_CMD_DAT	BIT(3)
diff --git a/drivers/char/ipmi/kcs_bmc_aspeed.c b/drivers/char/ipmi/kcs_bmc_aspeed.c
index 08d4290464d8..5bf8d013e4ae 100644
--- a/drivers/char/ipmi/kcs_bmc_aspeed.c
+++ b/drivers/char/ipmi/kcs_bmc_aspeed.c
@@ -60,10 +60,18 @@
 #define LPC_ODR4             0x118
 #define LPC_STR4             0x11C
 
+#define OBE_POLL_PERIOD	     (HZ / 2)
+
 struct aspeed_kcs_bmc {
 	struct kcs_bmc_device kcs_bmc;
 
 	struct regmap *map;
+
+	struct {
+		spinlock_t lock;
+		bool remove;
+		struct timer_list timer;
+	} obe;
 };
 
 struct aspeed_kcs_of_ops {
@@ -159,68 +167,89 @@ static void aspeed_kcs_enable_channel(struct kcs_bmc_device *kcs_bmc, bool enabl
 
 	switch (kcs_bmc->channel) {
 	case 1:
-		if (enable) {
-			regmap_update_bits(priv->map, LPC_HICR2,
-					LPC_HICR2_IBFIF1, LPC_HICR2_IBFIF1);
-			regmap_update_bits(priv->map, LPC_HICR0,
-					LPC_HICR0_LPC1E, LPC_HICR0_LPC1E);
-		} else {
-			regmap_update_bits(priv->map, LPC_HICR0,
-					LPC_HICR0_LPC1E, 0);
-			regmap_update_bits(priv->map, LPC_HICR2,
-					LPC_HICR2_IBFIF1, 0);
-		}
-		break;
-
+		regmap_update_bits(priv->map, LPC_HICR0, LPC_HICR0_LPC1E, enable * LPC_HICR0_LPC1E);
+		return;
 	case 2:
-		if (enable) {
-			regmap_update_bits(priv->map, LPC_HICR2,
-					LPC_HICR2_IBFIF2, LPC_HICR2_IBFIF2);
-			regmap_update_bits(priv->map, LPC_HICR0,
-					LPC_HICR0_LPC2E, LPC_HICR0_LPC2E);
-		} else {
-			regmap_update_bits(priv->map, LPC_HICR0,
-					LPC_HICR0_LPC2E, 0);
-			regmap_update_bits(priv->map, LPC_HICR2,
-					LPC_HICR2_IBFIF2, 0);
-		}
-		break;
-
+		regmap_update_bits(priv->map, LPC_HICR0, LPC_HICR0_LPC2E, enable * LPC_HICR0_LPC2E);
+		return;
 	case 3:
-		if (enable) {
-			regmap_update_bits(priv->map, LPC_HICR2,
-					LPC_HICR2_IBFIF3, LPC_HICR2_IBFIF3);
-			regmap_update_bits(priv->map, LPC_HICR0,
-					LPC_HICR0_LPC3E, LPC_HICR0_LPC3E);
-			regmap_update_bits(priv->map, LPC_HICR4,
-					LPC_HICR4_KCSENBL, LPC_HICR4_KCSENBL);
-		} else {
-			regmap_update_bits(priv->map, LPC_HICR0,
-					LPC_HICR0_LPC3E, 0);
-			regmap_update_bits(priv->map, LPC_HICR4,
-					LPC_HICR4_KCSENBL, 0);
-			regmap_update_bits(priv->map, LPC_HICR2,
-					LPC_HICR2_IBFIF3, 0);
-		}
-		break;
-
+		regmap_update_bits(priv->map, LPC_HICR0, LPC_HICR0_LPC3E, enable * LPC_HICR0_LPC3E);
+		regmap_update_bits(priv->map, LPC_HICR4,
+				   LPC_HICR4_KCSENBL, enable * LPC_HICR4_KCSENBL);
+		return;
 	case 4:
-		if (enable)
-			regmap_update_bits(priv->map, LPC_HICRB,
-					LPC_HICRB_IBFIF4 | LPC_HICRB_LPC4E,
-					LPC_HICRB_IBFIF4 | LPC_HICRB_LPC4E);
+		regmap_update_bits(priv->map, LPC_HICRB, LPC_HICRB_LPC4E, enable * LPC_HICRB_LPC4E);
+		return;
+	default:
+		pr_warn("%s: Unsupported channel: %d", __func__, kcs_bmc->channel);
+		return;
+	}
+}
+
+static void aspeed_kcs_check_obe(struct timer_list *timer)
+{
+	struct aspeed_kcs_bmc *priv = container_of(timer, struct aspeed_kcs_bmc, obe.timer);
+	unsigned long flags;
+	u8 str;
+
+	spin_lock_irqsave(&priv->obe.lock, flags);
+	if (priv->obe.remove) {
+		spin_unlock_irqrestore(&priv->obe.lock, flags);
+		return;
+	}
+
+	str = aspeed_kcs_inb(&priv->kcs_bmc, priv->kcs_bmc.ioreg.str);
+	if (str & KCS_BMC_STR_OBF) {
+		mod_timer(timer, jiffies + OBE_POLL_PERIOD);
+		spin_unlock_irqrestore(&priv->obe.lock, flags);
+		return;
+	}
+	spin_unlock_irqrestore(&priv->obe.lock, flags);
+
+	kcs_bmc_handle_event(&priv->kcs_bmc);
+}
+
+static void aspeed_kcs_irq_mask_update(struct kcs_bmc_device *kcs_bmc, u8 mask, u8 state)
+{
+	struct aspeed_kcs_bmc *priv = to_aspeed_kcs_bmc(kcs_bmc);
+
+	/* We don't have an OBE IRQ, emulate it */
+	if (mask & KCS_BMC_EVENT_TYPE_OBE) {
+		if (KCS_BMC_EVENT_TYPE_OBE & state)
+			mod_timer(&priv->obe.timer, jiffies + OBE_POLL_PERIOD);
 		else
-			regmap_update_bits(priv->map, LPC_HICRB,
-					LPC_HICRB_IBFIF4 | LPC_HICRB_LPC4E,
-					0);
-		break;
+			del_timer(&priv->obe.timer);
+	}
 
-	default:
-		break;
+	if (mask & KCS_BMC_EVENT_TYPE_IBF) {
+		const bool enable = !!(state & KCS_BMC_EVENT_TYPE_IBF);
+
+		switch (kcs_bmc->channel) {
+		case 1:
+			regmap_update_bits(priv->map, LPC_HICR2, LPC_HICR2_IBFIF1,
+					   enable * LPC_HICR2_IBFIF1);
+			return;
+		case 2:
+			regmap_update_bits(priv->map, LPC_HICR2, LPC_HICR2_IBFIF2,
+					   enable * LPC_HICR2_IBFIF2);
+			return;
+		case 3:
+			regmap_update_bits(priv->map, LPC_HICR2, LPC_HICR2_IBFIF3,
+					   enable * LPC_HICR2_IBFIF3);
+			return;
+		case 4:
+			regmap_update_bits(priv->map, LPC_HICRB, LPC_HICRB_IBFIF4,
+					   enable * LPC_HICRB_IBFIF4);
+			return;
+		default:
+			pr_warn("%s: Unsupported channel: %d", __func__, kcs_bmc->channel);
+			return;
+		}
 	}
 }
 
 static const struct kcs_bmc_device_ops aspeed_kcs_ops = {
+	.irq_mask_update = aspeed_kcs_irq_mask_update,
 	.io_inputb = aspeed_kcs_inb,
 	.io_outputb = aspeed_kcs_outb,
 	.io_updateb = aspeed_kcs_updateb,
@@ -375,6 +404,10 @@ static int aspeed_kcs_probe(struct platform_device *pdev)
 		return -ENODEV;
 	}
 
+	spin_lock_init(&priv->obe.lock);
+	priv->obe.remove = false;
+	timer_setup(&priv->obe.timer, aspeed_kcs_check_obe, 0);
+
 	aspeed_kcs_set_address(kcs_bmc, addr);
 
 	rc = aspeed_kcs_config_irq(kcs_bmc, pdev);
@@ -383,6 +416,8 @@ static int aspeed_kcs_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, priv);
 
+	aspeed_kcs_irq_mask_update(kcs_bmc, (KCS_BMC_EVENT_TYPE_IBF | KCS_BMC_EVENT_TYPE_OBE),
+				   KCS_BMC_EVENT_TYPE_IBF);
 	aspeed_kcs_enable_channel(kcs_bmc, true);
 
 	rc = kcs_bmc_add_device(&priv->kcs_bmc);
@@ -403,6 +438,15 @@ static int aspeed_kcs_remove(struct platform_device *pdev)
 
 	kcs_bmc_remove_device(kcs_bmc);
 
+	aspeed_kcs_enable_channel(kcs_bmc, false);
+	aspeed_kcs_irq_mask_update(kcs_bmc, (KCS_BMC_EVENT_TYPE_IBF | KCS_BMC_EVENT_TYPE_OBE), 0);
+
+	/* Make sure it's proper dead */
+	spin_lock_irq(&priv->obe.lock);
+	priv->obe.remove = true;
+	spin_unlock_irq(&priv->obe.lock);
+	del_timer_sync(&priv->obe.timer);
+
 	return 0;
 }
 
diff --git a/drivers/char/ipmi/kcs_bmc_client.h b/drivers/char/ipmi/kcs_bmc_client.h
index 814ad8e052ef..6fdcde0a7169 100644
--- a/drivers/char/ipmi/kcs_bmc_client.h
+++ b/drivers/char/ipmi/kcs_bmc_client.h
@@ -35,6 +35,8 @@ void kcs_bmc_unregister_driver(struct kcs_bmc_driver *drv);
 int kcs_bmc_enable_device(struct kcs_bmc_device *kcs_bmc, struct kcs_bmc_client *client);
 void kcs_bmc_disable_device(struct kcs_bmc_device *kcs_bmc, struct kcs_bmc_client *client);
 
+void kcs_bmc_update_event_mask(struct kcs_bmc_device *kcs_bmc, u8 mask, u8 events);
+
 u8 kcs_bmc_read_data(struct kcs_bmc_device *kcs_bmc);
 void kcs_bmc_write_data(struct kcs_bmc_device *kcs_bmc, u8 data);
 u8 kcs_bmc_read_status(struct kcs_bmc_device *kcs_bmc);
diff --git a/drivers/char/ipmi/kcs_bmc_device.h b/drivers/char/ipmi/kcs_bmc_device.h
index c9a4237bbf40..17c572f25c54 100644
--- a/drivers/char/ipmi/kcs_bmc_device.h
+++ b/drivers/char/ipmi/kcs_bmc_device.h
@@ -9,6 +9,7 @@
 #include "kcs_bmc.h"
 
 struct kcs_bmc_device_ops {
+	void (*irq_mask_update)(struct kcs_bmc_device *kcs_bmc, u8 mask, u8 enable);
 	u8 (*io_inputb)(struct kcs_bmc_device *kcs_bmc, u32 reg);
 	void (*io_outputb)(struct kcs_bmc_device *kcs_bmc, u32 reg, u8 b);
 	void (*io_updateb)(struct kcs_bmc_device *kcs_bmc, u32 reg, u8 mask, u8 b);
diff --git a/drivers/char/ipmi/kcs_bmc_npcm7xx.c b/drivers/char/ipmi/kcs_bmc_npcm7xx.c
index 3b96486c25c3..ef81a715f88a 100644
--- a/drivers/char/ipmi/kcs_bmc_npcm7xx.c
+++ b/drivers/char/ipmi/kcs_bmc_npcm7xx.c
@@ -38,6 +38,7 @@
 #define KCS2CTL		0x2A
 #define KCS3CTL		0x3C
 #define    KCS_CTL_IBFIE	BIT(0)
+#define    KCS_CTL_OBEIE	BIT(1)
 
 #define KCS1IE		0x1C
 #define KCS2IE		0x2E
@@ -117,13 +118,23 @@ static void npcm7xx_kcs_enable_channel(struct kcs_bmc_device *kcs_bmc, bool enab
 {
 	struct npcm7xx_kcs_bmc *priv = to_npcm7xx_kcs_bmc(kcs_bmc);
 
-	regmap_update_bits(priv->map, priv->reg->ctl, KCS_CTL_IBFIE,
-			   enable ? KCS_CTL_IBFIE : 0);
-
 	regmap_update_bits(priv->map, priv->reg->ie, KCS_IE_IRQE | KCS_IE_HIRQE,
 			   enable ? KCS_IE_IRQE | KCS_IE_HIRQE : 0);
 }
 
+static void npcm7xx_kcs_irq_mask_update(struct kcs_bmc_device *kcs_bmc, u8 mask, u8 state)
+{
+	struct npcm7xx_kcs_bmc *priv = to_npcm7xx_kcs_bmc(kcs_bmc);
+
+	if (mask & KCS_BMC_EVENT_TYPE_OBE)
+		regmap_update_bits(priv->map, priv->reg->ctl, KCS_CTL_OBEIE,
+				   !!(state & KCS_BMC_EVENT_TYPE_OBE) * KCS_CTL_OBEIE);
+
+	if (mask & KCS_BMC_EVENT_TYPE_IBF)
+		regmap_update_bits(priv->map, priv->reg->ctl, KCS_CTL_IBFIE,
+				   !!(state & KCS_BMC_EVENT_TYPE_IBF) * KCS_CTL_IBFIE);
+}
+
 static irqreturn_t npcm7xx_kcs_irq(int irq, void *arg)
 {
 	struct kcs_bmc_device *kcs_bmc = arg;
@@ -146,6 +157,7 @@ static int npcm7xx_kcs_config_irq(struct kcs_bmc_device *kcs_bmc,
 }
 
 static const struct kcs_bmc_device_ops npcm7xx_kcs_ops = {
+	.irq_mask_update = npcm7xx_kcs_irq_mask_update,
 	.io_inputb = npcm7xx_kcs_inb,
 	.io_outputb = npcm7xx_kcs_outb,
 	.io_updateb = npcm7xx_kcs_updateb,
@@ -186,11 +198,14 @@ static int npcm7xx_kcs_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, priv);
 
-	npcm7xx_kcs_enable_channel(kcs_bmc, true);
 	rc = npcm7xx_kcs_config_irq(kcs_bmc, pdev);
 	if (rc)
 		return rc;
 
+	npcm7xx_kcs_irq_mask_update(kcs_bmc, (KCS_BMC_EVENT_TYPE_IBF | KCS_BMC_EVENT_TYPE_OBE),
+				    KCS_BMC_EVENT_TYPE_IBF);
+	npcm7xx_kcs_enable_channel(kcs_bmc, true);
+
 	rc = kcs_bmc_add_device(kcs_bmc);
 	if (rc) {
 		dev_warn(&pdev->dev, "Failed to register channel %d: %d\n", kcs_bmc->channel, rc);
@@ -211,6 +226,9 @@ static int npcm7xx_kcs_remove(struct platform_device *pdev)
 
 	kcs_bmc_remove_device(kcs_bmc);
 
+	npcm7xx_kcs_enable_channel(kcs_bmc, false);
+	npcm7xx_kcs_irq_mask_update(kcs_bmc, (KCS_BMC_EVENT_TYPE_IBF | KCS_BMC_EVENT_TYPE_OBE), 0);
+
 	return 0;
 }
 
-- 
2.30.2


^ permalink raw reply related	[flat|nested] 23+ messages in thread

* [PATCH v4 10/16] ipmi: kcs_bmc: Enable IBF on open
  2021-06-08 10:47 [PATCH v4 00/16] ipmi: Allow raw access to KCS devices Andrew Jeffery
                   ` (8 preceding siblings ...)
  2021-06-08 10:47 ` [PATCH v4 09/16] ipmi: kcs_bmc: Allow clients to control KCS IRQ state Andrew Jeffery
@ 2021-06-08 10:47 ` Andrew Jeffery
  2021-06-08 10:47 ` [PATCH v4 11/16] ipmi: kcs_bmc: Add serio adaptor Andrew Jeffery
                   ` (6 subsequent siblings)
  16 siblings, 0 replies; 23+ messages in thread
From: Andrew Jeffery @ 2021-06-08 10:47 UTC (permalink / raw)
  To: openipmi-developer, openbmc, minyard
  Cc: devicetree, tmaimon77, linux-aspeed, avifishman70, venture,
	linux-kernel, tali.perry1, robh+dt, chiawei_wang,
	linux-arm-kernel, benjaminfair, arnd, zweiss, joel, KWLIU

This way devices don't get delivered IRQs when no-one is interested.

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
---
 drivers/char/ipmi/kcs_bmc.c         | 25 ++++++++++---------------
 drivers/char/ipmi/kcs_bmc_aspeed.c  |  3 +--
 drivers/char/ipmi/kcs_bmc_npcm7xx.c |  3 +--
 3 files changed, 12 insertions(+), 19 deletions(-)

diff --git a/drivers/char/ipmi/kcs_bmc.c b/drivers/char/ipmi/kcs_bmc.c
index 91eb43746cef..03d02a848f3a 100644
--- a/drivers/char/ipmi/kcs_bmc.c
+++ b/drivers/char/ipmi/kcs_bmc.c
@@ -55,24 +55,12 @@ EXPORT_SYMBOL(kcs_bmc_update_status);
 irqreturn_t kcs_bmc_handle_event(struct kcs_bmc_device *kcs_bmc)
 {
 	struct kcs_bmc_client *client;
-	irqreturn_t rc;
+	irqreturn_t rc = IRQ_NONE;
 
 	spin_lock(&kcs_bmc->lock);
 	client = kcs_bmc->client;
-	if (client) {
+	if (client)
 		rc = client->ops->event(client);
-	} else {
-		u8 status;
-
-		status = kcs_bmc_read_status(kcs_bmc);
-		if (status & KCS_BMC_STR_IBF) {
-			/* Ack the event by reading the data */
-			kcs_bmc_read_data(kcs_bmc);
-			rc = IRQ_HANDLED;
-		} else {
-			rc = IRQ_NONE;
-		}
-	}
 	spin_unlock(&kcs_bmc->lock);
 
 	return rc;
@@ -87,7 +75,10 @@ int kcs_bmc_enable_device(struct kcs_bmc_device *kcs_bmc, struct kcs_bmc_client
 	if (kcs_bmc->client) {
 		rc = -EBUSY;
 	} else {
+		u8 mask = KCS_BMC_EVENT_TYPE_IBF;
+
 		kcs_bmc->client = client;
+		kcs_bmc_update_event_mask(kcs_bmc, mask, mask);
 		rc = 0;
 	}
 	spin_unlock_irq(&kcs_bmc->lock);
@@ -99,8 +90,12 @@ EXPORT_SYMBOL(kcs_bmc_enable_device);
 void kcs_bmc_disable_device(struct kcs_bmc_device *kcs_bmc, struct kcs_bmc_client *client)
 {
 	spin_lock_irq(&kcs_bmc->lock);
-	if (client == kcs_bmc->client)
+	if (client == kcs_bmc->client) {
+		u8 mask = KCS_BMC_EVENT_TYPE_IBF | KCS_BMC_EVENT_TYPE_OBE;
+
+		kcs_bmc_update_event_mask(kcs_bmc, mask, 0);
 		kcs_bmc->client = NULL;
+	}
 	spin_unlock_irq(&kcs_bmc->lock);
 }
 EXPORT_SYMBOL(kcs_bmc_disable_device);
diff --git a/drivers/char/ipmi/kcs_bmc_aspeed.c b/drivers/char/ipmi/kcs_bmc_aspeed.c
index 5bf8d013e4ae..43994688dc8a 100644
--- a/drivers/char/ipmi/kcs_bmc_aspeed.c
+++ b/drivers/char/ipmi/kcs_bmc_aspeed.c
@@ -416,8 +416,7 @@ static int aspeed_kcs_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, priv);
 
-	aspeed_kcs_irq_mask_update(kcs_bmc, (KCS_BMC_EVENT_TYPE_IBF | KCS_BMC_EVENT_TYPE_OBE),
-				   KCS_BMC_EVENT_TYPE_IBF);
+	aspeed_kcs_irq_mask_update(kcs_bmc, (KCS_BMC_EVENT_TYPE_IBF | KCS_BMC_EVENT_TYPE_OBE), 0);
 	aspeed_kcs_enable_channel(kcs_bmc, true);
 
 	rc = kcs_bmc_add_device(&priv->kcs_bmc);
diff --git a/drivers/char/ipmi/kcs_bmc_npcm7xx.c b/drivers/char/ipmi/kcs_bmc_npcm7xx.c
index ef81a715f88a..7961fec56476 100644
--- a/drivers/char/ipmi/kcs_bmc_npcm7xx.c
+++ b/drivers/char/ipmi/kcs_bmc_npcm7xx.c
@@ -202,8 +202,7 @@ static int npcm7xx_kcs_probe(struct platform_device *pdev)
 	if (rc)
 		return rc;
 
-	npcm7xx_kcs_irq_mask_update(kcs_bmc, (KCS_BMC_EVENT_TYPE_IBF | KCS_BMC_EVENT_TYPE_OBE),
-				    KCS_BMC_EVENT_TYPE_IBF);
+	npcm7xx_kcs_irq_mask_update(kcs_bmc, (KCS_BMC_EVENT_TYPE_IBF | KCS_BMC_EVENT_TYPE_OBE), 0);
 	npcm7xx_kcs_enable_channel(kcs_bmc, true);
 
 	rc = kcs_bmc_add_device(kcs_bmc);
-- 
2.30.2


^ permalink raw reply related	[flat|nested] 23+ messages in thread

* [PATCH v4 11/16] ipmi: kcs_bmc: Add serio adaptor
  2021-06-08 10:47 [PATCH v4 00/16] ipmi: Allow raw access to KCS devices Andrew Jeffery
                   ` (9 preceding siblings ...)
  2021-06-08 10:47 ` [PATCH v4 10/16] ipmi: kcs_bmc: Enable IBF on open Andrew Jeffery
@ 2021-06-08 10:47 ` Andrew Jeffery
  2021-06-18 23:30   ` Zev Weiss
  2021-06-08 10:47 ` [PATCH v4 12/16] dt-bindings: ipmi: Convert ASPEED KCS binding to schema Andrew Jeffery
                   ` (5 subsequent siblings)
  16 siblings, 1 reply; 23+ messages in thread
From: Andrew Jeffery @ 2021-06-08 10:47 UTC (permalink / raw)
  To: openipmi-developer, openbmc, minyard
  Cc: devicetree, tmaimon77, linux-aspeed, avifishman70, venture,
	linux-kernel, tali.perry1, robh+dt, chiawei_wang,
	linux-arm-kernel, benjaminfair, arnd, zweiss, joel, KWLIU

kcs_bmc_serio acts as a bridge between the KCS drivers in the IPMI
subsystem and the existing userspace interfaces available through the
serio subsystem. This is useful when userspace would like to make use of
the BMC KCS devices for purposes that aren't IPMI.

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
---
 drivers/char/ipmi/Kconfig         |  14 +++
 drivers/char/ipmi/Makefile        |   1 +
 drivers/char/ipmi/kcs_bmc_serio.c | 157 ++++++++++++++++++++++++++++++
 3 files changed, 172 insertions(+)
 create mode 100644 drivers/char/ipmi/kcs_bmc_serio.c

diff --git a/drivers/char/ipmi/Kconfig b/drivers/char/ipmi/Kconfig
index bc5f81899b62..249b31197eea 100644
--- a/drivers/char/ipmi/Kconfig
+++ b/drivers/char/ipmi/Kconfig
@@ -137,6 +137,20 @@ config IPMI_KCS_BMC_CDEV_IPMI
 	  This support is also available as a module. The module will be
 	  called kcs_bmc_cdev_ipmi.
 
+config IPMI_KCS_BMC_SERIO
+	depends on IPMI_KCS_BMC && SERIO
+	tristate "SerIO adaptor for BMC KCS devices"
+	help
+	  Adapts the BMC KCS device for the SerIO subsystem. This allows users
+	  to take advantage of userspace interfaces provided by SerIO where
+	  appropriate.
+
+	  Say YES if you wish to expose KCS devices on the BMC via SerIO
+	  interfaces.
+
+	  This support is also available as a module. The module will be
+	  called kcs_bmc_serio.
+
 config ASPEED_BT_IPMI_BMC
 	depends on ARCH_ASPEED || COMPILE_TEST
 	depends on REGMAP && REGMAP_MMIO && MFD_SYSCON
diff --git a/drivers/char/ipmi/Makefile b/drivers/char/ipmi/Makefile
index fcfa676afddb..84f47d18007f 100644
--- a/drivers/char/ipmi/Makefile
+++ b/drivers/char/ipmi/Makefile
@@ -23,6 +23,7 @@ obj-$(CONFIG_IPMI_POWERNV) += ipmi_powernv.o
 obj-$(CONFIG_IPMI_WATCHDOG) += ipmi_watchdog.o
 obj-$(CONFIG_IPMI_POWEROFF) += ipmi_poweroff.o
 obj-$(CONFIG_IPMI_KCS_BMC) += kcs_bmc.o
+obj-$(CONFIG_IPMI_KCS_BMC_SERIO) += kcs_bmc_serio.o
 obj-$(CONFIG_IPMI_KCS_BMC_CDEV_IPMI) += kcs_bmc_cdev_ipmi.o
 obj-$(CONFIG_ASPEED_BT_IPMI_BMC) += bt-bmc.o
 obj-$(CONFIG_ASPEED_KCS_IPMI_BMC) += kcs_bmc_aspeed.o
diff --git a/drivers/char/ipmi/kcs_bmc_serio.c b/drivers/char/ipmi/kcs_bmc_serio.c
new file mode 100644
index 000000000000..7948cabde50b
--- /dev/null
+++ b/drivers/char/ipmi/kcs_bmc_serio.c
@@ -0,0 +1,157 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Copyright (c) 2021 IBM Corp. */
+
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/sched/signal.h>
+#include <linux/serio.h>
+#include <linux/slab.h>
+
+#include "kcs_bmc_client.h"
+
+struct kcs_bmc_serio {
+	struct list_head entry;
+
+	struct kcs_bmc_client client;
+	struct serio *port;
+
+	spinlock_t lock;
+};
+
+static inline struct kcs_bmc_serio *client_to_kcs_bmc_serio(struct kcs_bmc_client *client)
+{
+	return container_of(client, struct kcs_bmc_serio, client);
+}
+
+static irqreturn_t kcs_bmc_serio_event(struct kcs_bmc_client *client)
+{
+	struct kcs_bmc_serio *priv;
+	u8 handled = IRQ_NONE;
+	u8 status;
+
+	priv = client_to_kcs_bmc_serio(client);
+
+	spin_lock(&priv->lock);
+
+	status = kcs_bmc_read_status(client->dev);
+
+	if (status & KCS_BMC_STR_IBF)
+		handled = serio_interrupt(priv->port, kcs_bmc_read_data(client->dev), 0);
+
+	spin_unlock(&priv->lock);
+
+	return handled;
+}
+
+static const struct kcs_bmc_client_ops kcs_bmc_serio_client_ops = {
+	.event = kcs_bmc_serio_event,
+};
+
+static int kcs_bmc_serio_open(struct serio *port)
+{
+	struct kcs_bmc_serio *priv = port->port_data;
+
+	return kcs_bmc_enable_device(priv->client.dev, &priv->client);
+}
+
+static void kcs_bmc_serio_close(struct serio *port)
+{
+	struct kcs_bmc_serio *priv = port->port_data;
+
+	kcs_bmc_disable_device(priv->client.dev, &priv->client);
+}
+
+static DEFINE_SPINLOCK(kcs_bmc_serio_instances_lock);
+static LIST_HEAD(kcs_bmc_serio_instances);
+
+static int kcs_bmc_serio_add_device(struct kcs_bmc_device *kcs_bmc)
+{
+	struct kcs_bmc_serio *priv;
+	struct serio *port;
+
+	priv = devm_kzalloc(kcs_bmc->dev, sizeof(*priv), GFP_KERNEL);
+
+	/* Use kzalloc() as the allocation is cleaned up with kfree() via serio_unregister_port() */
+	port = kzalloc(sizeof(*port), GFP_KERNEL);
+	if (!(priv && port))
+		return -ENOMEM;
+
+	port->id.type = SERIO_8042;
+	port->open = kcs_bmc_serio_open;
+	port->close = kcs_bmc_serio_close;
+	port->port_data = priv;
+	port->dev.parent = kcs_bmc->dev;
+
+	spin_lock_init(&priv->lock);
+	priv->port = port;
+	priv->client.dev = kcs_bmc;
+	priv->client.ops = &kcs_bmc_serio_client_ops;
+
+	spin_lock_irq(&kcs_bmc_serio_instances_lock);
+	list_add(&priv->entry, &kcs_bmc_serio_instances);
+	spin_unlock_irq(&kcs_bmc_serio_instances_lock);
+
+	serio_register_port(port);
+
+	dev_info(kcs_bmc->dev, "Initialised serio client for channel %d", kcs_bmc->channel);
+
+	return 0;
+}
+
+static int kcs_bmc_serio_remove_device(struct kcs_bmc_device *kcs_bmc)
+{
+	struct kcs_bmc_serio *priv = NULL, *pos;
+
+	spin_lock_irq(&kcs_bmc_serio_instances_lock);
+	list_for_each_entry(pos, &kcs_bmc_serio_instances, entry) {
+		if (pos->client.dev == kcs_bmc) {
+			priv = pos;
+			list_del(&pos->entry);
+			break;
+		}
+	}
+	spin_unlock_irq(&kcs_bmc_serio_instances_lock);
+
+	if (!priv)
+		return -ENODEV;
+
+	/* kfree()s priv->port via put_device() */
+	serio_unregister_port(priv->port);
+
+	/* Ensure the IBF IRQ is disabled if we were the active client */
+	kcs_bmc_disable_device(kcs_bmc, &priv->client);
+
+	devm_kfree(priv->client.dev->dev, priv);
+
+	return 0;
+}
+
+static const struct kcs_bmc_driver_ops kcs_bmc_serio_driver_ops = {
+	.add_device = kcs_bmc_serio_add_device,
+	.remove_device = kcs_bmc_serio_remove_device,
+};
+
+static struct kcs_bmc_driver kcs_bmc_serio_driver = {
+	.ops = &kcs_bmc_serio_driver_ops,
+};
+
+static int kcs_bmc_serio_init(void)
+{
+	kcs_bmc_register_driver(&kcs_bmc_serio_driver);
+
+	return 0;
+}
+module_init(kcs_bmc_serio_init);
+
+static void kcs_bmc_serio_exit(void)
+{
+	kcs_bmc_unregister_driver(&kcs_bmc_serio_driver);
+}
+module_exit(kcs_bmc_serio_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Andrew Jeffery <andrew@aj.id.au>");
+MODULE_DESCRIPTION("Adapter driver for serio access to BMC KCS devices");
-- 
2.30.2


^ permalink raw reply related	[flat|nested] 23+ messages in thread

* [PATCH v4 12/16] dt-bindings: ipmi: Convert ASPEED KCS binding to schema
  2021-06-08 10:47 [PATCH v4 00/16] ipmi: Allow raw access to KCS devices Andrew Jeffery
                   ` (10 preceding siblings ...)
  2021-06-08 10:47 ` [PATCH v4 11/16] ipmi: kcs_bmc: Add serio adaptor Andrew Jeffery
@ 2021-06-08 10:47 ` Andrew Jeffery
  2021-06-08 10:47 ` [PATCH v4 13/16] dt-bindings: ipmi: Add optional SerIRQ property to ASPEED KCS devices Andrew Jeffery
                   ` (4 subsequent siblings)
  16 siblings, 0 replies; 23+ messages in thread
From: Andrew Jeffery @ 2021-06-08 10:47 UTC (permalink / raw)
  To: openipmi-developer, openbmc, minyard
  Cc: devicetree, tmaimon77, linux-aspeed, avifishman70, venture,
	linux-kernel, tali.perry1, robh+dt, chiawei_wang,
	linux-arm-kernel, benjaminfair, arnd, zweiss, joel, KWLIU,
	Rob Herring

Given the deprecated binding, improve the ability to detect issues in
the platform devicetrees. Further, a subsequent patch will introduce a
new interrupts property for specifying SerIRQ behaviour, so convert
before we do any further additions.

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Zev Weiss <zweiss@equinix.com>
---
 .../bindings/ipmi/aspeed,ast2400-kcs-bmc.yaml | 92 +++++++++++++++++++
 .../bindings/ipmi/aspeed-kcs-bmc.txt          | 33 -------
 2 files changed, 92 insertions(+), 33 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/ipmi/aspeed,ast2400-kcs-bmc.yaml
 delete mode 100644 Documentation/devicetree/bindings/ipmi/aspeed-kcs-bmc.txt

diff --git a/Documentation/devicetree/bindings/ipmi/aspeed,ast2400-kcs-bmc.yaml b/Documentation/devicetree/bindings/ipmi/aspeed,ast2400-kcs-bmc.yaml
new file mode 100644
index 000000000000..697ca575454f
--- /dev/null
+++ b/Documentation/devicetree/bindings/ipmi/aspeed,ast2400-kcs-bmc.yaml
@@ -0,0 +1,92 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/ipmi/aspeed,ast2400-kcs-bmc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: ASPEED BMC KCS Devices
+
+maintainers:
+  - Andrew Jeffery <andrew@aj.id.au>
+
+description: |
+  The Aspeed BMC SoCs typically use the Keyboard-Controller-Style (KCS)
+  interfaces on the LPC bus for in-band IPMI communication with their host.
+
+properties:
+  compatible:
+    oneOf:
+      - description: Channel ID derived from reg
+        items:
+          enum:
+            - aspeed,ast2400-kcs-bmc-v2
+            - aspeed,ast2500-kcs-bmc-v2
+            - aspeed,ast2600-kcs-bmc
+
+      - description: Old-style with explicit channel ID, no reg
+        deprecated: true
+        items:
+          enum:
+            - aspeed,ast2400-kcs-bmc
+            - aspeed,ast2500-kcs-bmc
+
+  interrupts:
+    maxItems: 1
+
+  reg:
+    # maxItems: 3
+    items:
+      - description: IDR register
+      - description: ODR register
+      - description: STR register
+
+  aspeed,lpc-io-reg:
+    $ref: '/schemas/types.yaml#/definitions/uint32-array'
+    minItems: 1
+    maxItems: 2
+    description: |
+      The host CPU LPC IO data and status addresses for the device. For most
+      channels the status address is derived from the data address, but the
+      status address may be optionally provided.
+
+  kcs_chan:
+    deprecated: true
+    $ref: '/schemas/types.yaml#/definitions/uint32'
+    description: The LPC channel number in the controller
+
+  kcs_addr:
+    deprecated: true
+    $ref: '/schemas/types.yaml#/definitions/uint32'
+    description: The host CPU IO map address
+
+required:
+  - compatible
+  - interrupts
+
+additionalProperties: false
+
+allOf:
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - aspeed,ast2400-kcs-bmc
+              - aspeed,ast2500-kcs-bmc
+    then:
+      required:
+        - kcs_chan
+        - kcs_addr
+    else:
+      required:
+        - reg
+        - aspeed,lpc-io-reg
+
+examples:
+  - |
+    kcs3: kcs@24 {
+        compatible = "aspeed,ast2600-kcs-bmc";
+        reg = <0x24 0x1>, <0x30 0x1>, <0x3c 0x1>;
+        aspeed,lpc-io-reg = <0xca2>;
+        interrupts = <8>;
+    };
diff --git a/Documentation/devicetree/bindings/ipmi/aspeed-kcs-bmc.txt b/Documentation/devicetree/bindings/ipmi/aspeed-kcs-bmc.txt
deleted file mode 100644
index 193e71ca96b0..000000000000
--- a/Documentation/devicetree/bindings/ipmi/aspeed-kcs-bmc.txt
+++ /dev/null
@@ -1,33 +0,0 @@
-# Aspeed KCS (Keyboard Controller Style) IPMI interface
-
-The Aspeed SOCs (AST2400 and AST2500) are commonly used as BMCs
-(Baseboard Management Controllers) and the KCS interface can be
-used to perform in-band IPMI communication with their host.
-
-## v1
-Required properties:
-- compatible : should be one of
-    "aspeed,ast2400-kcs-bmc"
-    "aspeed,ast2500-kcs-bmc"
-- interrupts : interrupt generated by the controller
-- kcs_chan : The LPC channel number in the controller
-- kcs_addr : The host CPU IO map address
-
-## v2
-Required properties:
-- compatible : should be one of
-    "aspeed,ast2400-kcs-bmc-v2"
-    "aspeed,ast2500-kcs-bmc-v2"
-- reg : The address and size of the IDR, ODR and STR registers
-- interrupts : interrupt generated by the controller
-- aspeed,lpc-io-reg : The host CPU LPC IO address for the device
-
-Example:
-
-    kcs3: kcs@24 {
-        compatible = "aspeed,ast2500-kcs-bmc-v2";
-        reg = <0x24 0x1>, <0x30 0x1>, <0x3c 0x1>;
-        aspeed,lpc-reg = <0xca2>;
-        interrupts = <8>;
-        status = "okay";
-    };
-- 
2.30.2


^ permalink raw reply related	[flat|nested] 23+ messages in thread

* [PATCH v4 13/16] dt-bindings: ipmi: Add optional SerIRQ property to ASPEED KCS devices
  2021-06-08 10:47 [PATCH v4 00/16] ipmi: Allow raw access to KCS devices Andrew Jeffery
                   ` (11 preceding siblings ...)
  2021-06-08 10:47 ` [PATCH v4 12/16] dt-bindings: ipmi: Convert ASPEED KCS binding to schema Andrew Jeffery
@ 2021-06-08 10:47 ` Andrew Jeffery
  2021-06-08 10:47 ` [PATCH v4 14/16] ipmi: kcs_bmc_aspeed: Implement KCS SerIRQ configuration Andrew Jeffery
                   ` (3 subsequent siblings)
  16 siblings, 0 replies; 23+ messages in thread
From: Andrew Jeffery @ 2021-06-08 10:47 UTC (permalink / raw)
  To: openipmi-developer, openbmc, minyard
  Cc: devicetree, tmaimon77, linux-aspeed, avifishman70, venture,
	linux-kernel, tali.perry1, robh+dt, chiawei_wang,
	linux-arm-kernel, benjaminfair, arnd, zweiss, joel, KWLIU,
	Rob Herring

Allocating IO and IRQ resources to LPC devices is in-theory an operation
for the host, however ASPEED don't appear to expose this capability
outside the BMC (e.g. SuperIO). Instead, we are left with BMC-internal
registers for managing these resources, so introduce a devicetree
property for KCS devices to describe SerIRQ properties.

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Reviewed-by: Rob Herring <robh@kernel.org>
---
 .../bindings/ipmi/aspeed,ast2400-kcs-bmc.yaml      | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/Documentation/devicetree/bindings/ipmi/aspeed,ast2400-kcs-bmc.yaml b/Documentation/devicetree/bindings/ipmi/aspeed,ast2400-kcs-bmc.yaml
index 697ca575454f..4ff6fabfcb30 100644
--- a/Documentation/devicetree/bindings/ipmi/aspeed,ast2400-kcs-bmc.yaml
+++ b/Documentation/devicetree/bindings/ipmi/aspeed,ast2400-kcs-bmc.yaml
@@ -49,6 +49,18 @@ properties:
       channels the status address is derived from the data address, but the
       status address may be optionally provided.
 
+  aspeed,lpc-interrupts:
+    $ref: "/schemas/types.yaml#/definitions/uint32-array"
+    minItems: 2
+    maxItems: 2
+    description: |
+      A 2-cell property expressing the LPC SerIRQ number and the interrupt
+      level/sense encoding (specified in the standard fashion).
+
+      Note that the generated interrupt is issued from the BMC to the host, and
+      thus the target interrupt controller is not captured by the BMC's
+      devicetree.
+
   kcs_chan:
     deprecated: true
     $ref: '/schemas/types.yaml#/definitions/uint32'
@@ -84,9 +96,11 @@ allOf:
 
 examples:
   - |
+    #include <dt-bindings/interrupt-controller/irq.h>
     kcs3: kcs@24 {
         compatible = "aspeed,ast2600-kcs-bmc";
         reg = <0x24 0x1>, <0x30 0x1>, <0x3c 0x1>;
         aspeed,lpc-io-reg = <0xca2>;
+        aspeed,lpc-interrupts = <11 IRQ_TYPE_LEVEL_LOW>;
         interrupts = <8>;
     };
-- 
2.30.2


^ permalink raw reply related	[flat|nested] 23+ messages in thread

* [PATCH v4 14/16] ipmi: kcs_bmc_aspeed: Implement KCS SerIRQ configuration
  2021-06-08 10:47 [PATCH v4 00/16] ipmi: Allow raw access to KCS devices Andrew Jeffery
                   ` (12 preceding siblings ...)
  2021-06-08 10:47 ` [PATCH v4 13/16] dt-bindings: ipmi: Add optional SerIRQ property to ASPEED KCS devices Andrew Jeffery
@ 2021-06-08 10:47 ` Andrew Jeffery
  2021-06-08 10:47 ` [PATCH v4 15/16] ipmi: kcs_bmc_aspeed: Fix IBFIE typo from datasheet Andrew Jeffery
                   ` (2 subsequent siblings)
  16 siblings, 0 replies; 23+ messages in thread
From: Andrew Jeffery @ 2021-06-08 10:47 UTC (permalink / raw)
  To: openipmi-developer, openbmc, minyard
  Cc: devicetree, tmaimon77, linux-aspeed, avifishman70, venture,
	linux-kernel, tali.perry1, robh+dt, chiawei_wang,
	linux-arm-kernel, benjaminfair, arnd, zweiss, joel, KWLIU

Apply the SerIRQ ID and level/sense behaviours from the devicetree if
provided.

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
---
 drivers/char/ipmi/kcs_bmc_aspeed.c | 182 ++++++++++++++++++++++++++++-
 1 file changed, 180 insertions(+), 2 deletions(-)

diff --git a/drivers/char/ipmi/kcs_bmc_aspeed.c b/drivers/char/ipmi/kcs_bmc_aspeed.c
index 43994688dc8a..922fe41f6b05 100644
--- a/drivers/char/ipmi/kcs_bmc_aspeed.c
+++ b/drivers/char/ipmi/kcs_bmc_aspeed.c
@@ -9,6 +9,7 @@
 #include <linux/errno.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
+#include <linux/irq.h>
 #include <linux/mfd/syscon.h>
 #include <linux/module.h>
 #include <linux/of.h>
@@ -28,6 +29,22 @@
 
 #define KCS_CHANNEL_MAX     4
 
+/*
+ * Field class descriptions
+ *
+ * LPCyE	Enable LPC channel y
+ * IBFIEy	Input Buffer Full IRQ Enable for LPC channel y
+ * IRQxEy	Assert SerIRQ x for LPC channel y (Deprecated, use IDyIRQX, IRQXEy)
+ * IDyIRQX	Use the specified 4-bit SerIRQ for LPC channel y
+ * SELyIRQX	SerIRQ polarity for LPC channel y (low: 0, high: 1)
+ * IRQXEy	Assert the SerIRQ specified in IDyIRQX for LPC channel y
+ */
+
+#define LPC_TYIRQX_LOW       0b00
+#define LPC_TYIRQX_HIGH      0b01
+#define LPC_TYIRQX_RSVD      0b10
+#define LPC_TYIRQX_RISING    0b11
+
 #define LPC_HICR0            0x000
 #define     LPC_HICR0_LPC3E          BIT(7)
 #define     LPC_HICR0_LPC2E          BIT(6)
@@ -39,6 +56,19 @@
 #define LPC_HICR4            0x010
 #define     LPC_HICR4_LADR12AS       BIT(7)
 #define     LPC_HICR4_KCSENBL        BIT(2)
+#define LPC_SIRQCR0	     0x070
+/* IRQ{12,1}E1 are deprecated as of AST2600 A3 but necessary for prior chips */
+#define     LPC_SIRQCR0_IRQ12E1	     BIT(1)
+#define     LPC_SIRQCR0_IRQ1E1	     BIT(0)
+#define LPC_HICR5	     0x080
+#define     LPC_HICR5_ID3IRQX_MASK   GENMASK(23, 20)
+#define     LPC_HICR5_ID3IRQX_SHIFT  20
+#define     LPC_HICR5_ID2IRQX_MASK   GENMASK(19, 16)
+#define     LPC_HICR5_ID2IRQX_SHIFT  16
+#define     LPC_HICR5_SEL3IRQX       BIT(15)
+#define     LPC_HICR5_IRQXE3         BIT(14)
+#define     LPC_HICR5_SEL2IRQX       BIT(13)
+#define     LPC_HICR5_IRQXE2         BIT(12)
 #define LPC_LADR3H           0x014
 #define LPC_LADR3L           0x018
 #define LPC_LADR12H          0x01C
@@ -55,6 +85,13 @@
 #define LPC_HICRB            0x100
 #define     LPC_HICRB_IBFIF4         BIT(1)
 #define     LPC_HICRB_LPC4E          BIT(0)
+#define LPC_HICRC            0x104
+#define     LPC_HICRC_ID4IRQX_MASK   GENMASK(7, 4)
+#define     LPC_HICRC_ID4IRQX_SHIFT  4
+#define     LPC_HICRC_TY4IRQX_MASK   GENMASK(3, 2)
+#define     LPC_HICRC_TY4IRQX_SHIFT  2
+#define     LPC_HICRC_OBF4_AUTO_CLR  BIT(1)
+#define     LPC_HICRC_IRQXE4         BIT(0)
 #define LPC_LADR4            0x110
 #define LPC_IDR4             0x114
 #define LPC_ODR4             0x118
@@ -62,11 +99,21 @@
 
 #define OBE_POLL_PERIOD	     (HZ / 2)
 
+enum aspeed_kcs_irq_mode {
+	aspeed_kcs_irq_none,
+	aspeed_kcs_irq_serirq,
+};
+
 struct aspeed_kcs_bmc {
 	struct kcs_bmc_device kcs_bmc;
 
 	struct regmap *map;
 
+	struct {
+		enum aspeed_kcs_irq_mode mode;
+		int id;
+	} upstream_irq;
+
 	struct {
 		spinlock_t lock;
 		bool remove;
@@ -103,6 +150,49 @@ static void aspeed_kcs_outb(struct kcs_bmc_device *kcs_bmc, u32 reg, u8 data)
 
 	rc = regmap_write(priv->map, reg, data);
 	WARN(rc != 0, "regmap_write() failed: %d\n", rc);
+
+	/* Trigger the upstream IRQ on ODR writes, if enabled */
+
+	switch (reg) {
+	case LPC_ODR1:
+	case LPC_ODR2:
+	case LPC_ODR3:
+	case LPC_ODR4:
+		break;
+	default:
+		return;
+	}
+
+	if (priv->upstream_irq.mode != aspeed_kcs_irq_serirq)
+		return;
+
+	switch (kcs_bmc->channel) {
+	case 1:
+		switch (priv->upstream_irq.id) {
+		case 12:
+			regmap_update_bits(priv->map, LPC_SIRQCR0, LPC_SIRQCR0_IRQ12E1,
+					   LPC_SIRQCR0_IRQ12E1);
+			break;
+		case 1:
+			regmap_update_bits(priv->map, LPC_SIRQCR0, LPC_SIRQCR0_IRQ1E1,
+					   LPC_SIRQCR0_IRQ1E1);
+			break;
+		default:
+			break;
+		}
+		break;
+	case 2:
+		regmap_update_bits(priv->map, LPC_HICR5, LPC_HICR5_IRQXE2, LPC_HICR5_IRQXE2);
+		break;
+	case 3:
+		regmap_update_bits(priv->map, LPC_HICR5, LPC_HICR5_IRQXE3, LPC_HICR5_IRQXE3);
+		break;
+	case 4:
+		regmap_update_bits(priv->map, LPC_HICRC, LPC_HICRC_IRQXE4, LPC_HICRC_IRQXE4);
+		break;
+	default:
+		break;
+	}
 }
 
 static void aspeed_kcs_updateb(struct kcs_bmc_device *kcs_bmc, u32 reg, u8 mask, u8 val)
@@ -161,6 +251,73 @@ static void aspeed_kcs_set_address(struct kcs_bmc_device *kcs_bmc, u16 addr)
 	}
 }
 
+static inline int aspeed_kcs_map_serirq_type(u32 dt_type)
+{
+	switch (dt_type) {
+	case IRQ_TYPE_EDGE_RISING:
+		return LPC_TYIRQX_RISING;
+	case IRQ_TYPE_LEVEL_HIGH:
+		return LPC_TYIRQX_HIGH;
+	case IRQ_TYPE_LEVEL_LOW:
+		return LPC_TYIRQX_LOW;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int aspeed_kcs_config_upstream_irq(struct aspeed_kcs_bmc *priv, u32 id, u32 dt_type)
+{
+	unsigned int mask, val, hw_type;
+
+	if (id > 15)
+		return -EINVAL;
+
+	hw_type = aspeed_kcs_map_serirq_type(dt_type);
+	if (hw_type < 0)
+		return hw_type;
+
+	priv->upstream_irq.mode = aspeed_kcs_irq_serirq;
+	priv->upstream_irq.id = id;
+
+	switch (priv->kcs_bmc.channel) {
+	case 1:
+		/* Needs IRQxE1 rather than (ID1IRQX, SEL1IRQX, IRQXE1) before AST2600 A3 */
+		break;
+	case 2:
+		if (!(hw_type == LPC_TYIRQX_LOW || hw_type == LPC_TYIRQX_HIGH))
+			return -EINVAL;
+
+		mask = LPC_HICR5_SEL2IRQX | LPC_HICR5_ID2IRQX_MASK;
+		val = (id << LPC_HICR5_ID2IRQX_SHIFT);
+		val |= (hw_type == LPC_TYIRQX_HIGH) ? LPC_HICR5_SEL2IRQX : 0;
+		regmap_update_bits(priv->map, LPC_HICR5, mask, val);
+
+		break;
+	case 3:
+		if (!(hw_type == LPC_TYIRQX_LOW || hw_type == LPC_TYIRQX_HIGH))
+			return -EINVAL;
+
+		mask = LPC_HICR5_SEL3IRQX | LPC_HICR5_ID3IRQX_MASK;
+		val = (id << LPC_HICR5_ID3IRQX_SHIFT);
+		val |= (hw_type == LPC_TYIRQX_HIGH) ? LPC_HICR5_SEL3IRQX : 0;
+		regmap_update_bits(priv->map, LPC_HICR5, mask, val);
+
+		break;
+	case 4:
+		mask = LPC_HICRC_ID4IRQX_MASK | LPC_HICRC_TY4IRQX_MASK | LPC_HICRC_OBF4_AUTO_CLR;
+		val = (id << LPC_HICRC_ID4IRQX_SHIFT) | (hw_type << LPC_HICRC_TY4IRQX_SHIFT);
+		regmap_update_bits(priv->map, LPC_HICRC, mask, val);
+		break;
+	default:
+		dev_warn(priv->kcs_bmc.dev,
+			 "SerIRQ configuration not supported on KCS channel %d\n",
+			 priv->kcs_bmc.channel);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
 static void aspeed_kcs_enable_channel(struct kcs_bmc_device *kcs_bmc, bool enable)
 {
 	struct aspeed_kcs_bmc *priv = to_aspeed_kcs_bmc(kcs_bmc);
@@ -262,7 +419,7 @@ static irqreturn_t aspeed_kcs_irq(int irq, void *arg)
 	return kcs_bmc_handle_event(kcs_bmc);
 }
 
-static int aspeed_kcs_config_irq(struct kcs_bmc_device *kcs_bmc,
+static int aspeed_kcs_config_downstream_irq(struct kcs_bmc_device *kcs_bmc,
 			struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
@@ -368,6 +525,8 @@ static int aspeed_kcs_probe(struct platform_device *pdev)
 	struct aspeed_kcs_bmc *priv;
 	struct device_node *np;
 	int rc, channel, addr;
+	bool have_upstream_irq;
+	u32 upstream_irq[2];
 
 	np = pdev->dev.of_node->parent;
 	if (!of_device_is_compatible(np, "aspeed,ast2400-lpc-v2") &&
@@ -376,6 +535,7 @@ static int aspeed_kcs_probe(struct platform_device *pdev)
 		dev_err(&pdev->dev, "unsupported LPC device binding\n");
 		return -ENODEV;
 	}
+
 	ops = of_device_get_match_data(&pdev->dev);
 	if (!ops)
 		return -EINVAL;
@@ -388,6 +548,13 @@ static int aspeed_kcs_probe(struct platform_device *pdev)
 	if (addr < 0)
 		return addr;
 
+	np = pdev->dev.of_node;
+	rc = of_property_read_u32_array(np, "aspeed,lpc-interrupts", upstream_irq, 2);
+	if (rc && rc != -EINVAL)
+		return -EINVAL;
+
+	have_upstream_irq = !rc;
+
 	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
 	if (!priv)
 		return -ENOMEM;
@@ -410,10 +577,20 @@ static int aspeed_kcs_probe(struct platform_device *pdev)
 
 	aspeed_kcs_set_address(kcs_bmc, addr);
 
-	rc = aspeed_kcs_config_irq(kcs_bmc, pdev);
+	/* Host to BMC IRQ */
+	rc = aspeed_kcs_config_downstream_irq(kcs_bmc, pdev);
 	if (rc)
 		return rc;
 
+	/* BMC to Host IRQ */
+	if (have_upstream_irq) {
+		rc = aspeed_kcs_config_upstream_irq(priv, upstream_irq[0], upstream_irq[1]);
+		if (rc < 0)
+			return rc;
+	} else {
+		priv->upstream_irq.mode = aspeed_kcs_irq_none;
+	}
+
 	platform_set_drvdata(pdev, priv);
 
 	aspeed_kcs_irq_mask_update(kcs_bmc, (KCS_BMC_EVENT_TYPE_IBF | KCS_BMC_EVENT_TYPE_OBE), 0);
@@ -480,4 +657,5 @@ module_platform_driver(ast_kcs_bmc_driver);
 
 MODULE_LICENSE("GPL v2");
 MODULE_AUTHOR("Haiyue Wang <haiyue.wang@linux.intel.com>");
+MODULE_AUTHOR("Andrew Jeffery <andrew@aj.id.au>");
 MODULE_DESCRIPTION("Aspeed device interface to the KCS BMC device");
-- 
2.30.2


^ permalink raw reply related	[flat|nested] 23+ messages in thread

* [PATCH v4 15/16] ipmi: kcs_bmc_aspeed: Fix IBFIE typo from datasheet
  2021-06-08 10:47 [PATCH v4 00/16] ipmi: Allow raw access to KCS devices Andrew Jeffery
                   ` (13 preceding siblings ...)
  2021-06-08 10:47 ` [PATCH v4 14/16] ipmi: kcs_bmc_aspeed: Implement KCS SerIRQ configuration Andrew Jeffery
@ 2021-06-08 10:47 ` Andrew Jeffery
  2021-06-08 10:47 ` [PATCH v4 16/16] ipmi: kcs_bmc_aspeed: Optionally apply status address Andrew Jeffery
  2021-06-15 18:46 ` [PATCH v4 00/16] ipmi: Allow raw access to KCS devices Corey Minyard
  16 siblings, 0 replies; 23+ messages in thread
From: Andrew Jeffery @ 2021-06-08 10:47 UTC (permalink / raw)
  To: openipmi-developer, openbmc, minyard
  Cc: devicetree, tmaimon77, linux-aspeed, avifishman70, venture,
	linux-kernel, tali.perry1, robh+dt, chiawei_wang,
	linux-arm-kernel, benjaminfair, arnd, zweiss, joel, KWLIU

Input Buffer Full Interrupt Enable (IBFIE) is typoed as IBFIF for some
registers in the datasheet. Fix the driver to use the sensible acronym.

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Reviewed-by: Zev Weiss <zweiss@equinix.com>
---
 drivers/char/ipmi/kcs_bmc_aspeed.c | 24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/drivers/char/ipmi/kcs_bmc_aspeed.c b/drivers/char/ipmi/kcs_bmc_aspeed.c
index 922fe41f6b05..461cb2c9cc7e 100644
--- a/drivers/char/ipmi/kcs_bmc_aspeed.c
+++ b/drivers/char/ipmi/kcs_bmc_aspeed.c
@@ -50,9 +50,9 @@
 #define     LPC_HICR0_LPC2E          BIT(6)
 #define     LPC_HICR0_LPC1E          BIT(5)
 #define LPC_HICR2            0x008
-#define     LPC_HICR2_IBFIF3         BIT(3)
-#define     LPC_HICR2_IBFIF2         BIT(2)
-#define     LPC_HICR2_IBFIF1         BIT(1)
+#define     LPC_HICR2_IBFIE3         BIT(3)
+#define     LPC_HICR2_IBFIE2         BIT(2)
+#define     LPC_HICR2_IBFIE1         BIT(1)
 #define LPC_HICR4            0x010
 #define     LPC_HICR4_LADR12AS       BIT(7)
 #define     LPC_HICR4_KCSENBL        BIT(2)
@@ -83,7 +83,7 @@
 #define LPC_STR2             0x040
 #define LPC_STR3             0x044
 #define LPC_HICRB            0x100
-#define     LPC_HICRB_IBFIF4         BIT(1)
+#define     LPC_HICRB_IBFIE4         BIT(1)
 #define     LPC_HICRB_LPC4E          BIT(0)
 #define LPC_HICRC            0x104
 #define     LPC_HICRC_ID4IRQX_MASK   GENMASK(7, 4)
@@ -383,20 +383,20 @@ static void aspeed_kcs_irq_mask_update(struct kcs_bmc_device *kcs_bmc, u8 mask,
 
 		switch (kcs_bmc->channel) {
 		case 1:
-			regmap_update_bits(priv->map, LPC_HICR2, LPC_HICR2_IBFIF1,
-					   enable * LPC_HICR2_IBFIF1);
+			regmap_update_bits(priv->map, LPC_HICR2, LPC_HICR2_IBFIE1,
+					   enable * LPC_HICR2_IBFIE1);
 			return;
 		case 2:
-			regmap_update_bits(priv->map, LPC_HICR2, LPC_HICR2_IBFIF2,
-					   enable * LPC_HICR2_IBFIF2);
+			regmap_update_bits(priv->map, LPC_HICR2, LPC_HICR2_IBFIE2,
+					   enable * LPC_HICR2_IBFIE2);
 			return;
 		case 3:
-			regmap_update_bits(priv->map, LPC_HICR2, LPC_HICR2_IBFIF3,
-					   enable * LPC_HICR2_IBFIF3);
+			regmap_update_bits(priv->map, LPC_HICR2, LPC_HICR2_IBFIE3,
+					   enable * LPC_HICR2_IBFIE3);
 			return;
 		case 4:
-			regmap_update_bits(priv->map, LPC_HICRB, LPC_HICRB_IBFIF4,
-					   enable * LPC_HICRB_IBFIF4);
+			regmap_update_bits(priv->map, LPC_HICRB, LPC_HICRB_IBFIE4,
+					   enable * LPC_HICRB_IBFIE4);
 			return;
 		default:
 			pr_warn("%s: Unsupported channel: %d", __func__, kcs_bmc->channel);
-- 
2.30.2


^ permalink raw reply related	[flat|nested] 23+ messages in thread

* [PATCH v4 16/16] ipmi: kcs_bmc_aspeed: Optionally apply status address
  2021-06-08 10:47 [PATCH v4 00/16] ipmi: Allow raw access to KCS devices Andrew Jeffery
                   ` (14 preceding siblings ...)
  2021-06-08 10:47 ` [PATCH v4 15/16] ipmi: kcs_bmc_aspeed: Fix IBFIE typo from datasheet Andrew Jeffery
@ 2021-06-08 10:47 ` Andrew Jeffery
  2021-06-15 18:46 ` [PATCH v4 00/16] ipmi: Allow raw access to KCS devices Corey Minyard
  16 siblings, 0 replies; 23+ messages in thread
From: Andrew Jeffery @ 2021-06-08 10:47 UTC (permalink / raw)
  To: openipmi-developer, openbmc, minyard
  Cc: devicetree, tmaimon77, linux-aspeed, avifishman70, venture,
	linux-kernel, tali.perry1, robh+dt, chiawei_wang,
	linux-arm-kernel, benjaminfair, arnd, zweiss, joel, KWLIU

Some Aspeed KCS devices can derive the status register address from the
address of the data register. As such, the address of the status
register can be implicit in the configuration if desired. On the other
hand, sometimes address schemes might be requested that are incompatible
with the default addressing scheme. Allow these requests where possible
if the devicetree specifies the status register address.

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Reviewed-by: Chia-Wei Wang <chiawei_wang@aspeedtech.com>
---
 drivers/char/ipmi/kcs_bmc_aspeed.c | 116 +++++++++++++++++++++--------
 1 file changed, 83 insertions(+), 33 deletions(-)

diff --git a/drivers/char/ipmi/kcs_bmc_aspeed.c b/drivers/char/ipmi/kcs_bmc_aspeed.c
index 461cb2c9cc7e..0401089f8895 100644
--- a/drivers/char/ipmi/kcs_bmc_aspeed.c
+++ b/drivers/char/ipmi/kcs_bmc_aspeed.c
@@ -83,6 +83,8 @@
 #define LPC_STR2             0x040
 #define LPC_STR3             0x044
 #define LPC_HICRB            0x100
+#define     LPC_HICRB_EN16LADR2      BIT(5)
+#define     LPC_HICRB_EN16LADR1      BIT(4)
 #define     LPC_HICRB_IBFIE4         BIT(1)
 #define     LPC_HICRB_LPC4E          BIT(0)
 #define LPC_HICRC            0x104
@@ -96,6 +98,11 @@
 #define LPC_IDR4             0x114
 #define LPC_ODR4             0x118
 #define LPC_STR4             0x11C
+#define LPC_LSADR12	     0x120
+#define     LPC_LSADR12_LSADR2_MASK  GENMASK(31, 16)
+#define     LPC_LSADR12_LSADR2_SHIFT 16
+#define     LPC_LSADR12_LSADR1_MASK  GENMASK(15, 0)
+#define     LPC_LSADR12_LSADR1_SHIFT 0
 
 #define OBE_POLL_PERIOD	     (HZ / 2)
 
@@ -123,7 +130,7 @@ struct aspeed_kcs_bmc {
 
 struct aspeed_kcs_of_ops {
 	int (*get_channel)(struct platform_device *pdev);
-	int (*get_io_address)(struct platform_device *pdev);
+	int (*get_io_address)(struct platform_device *pdev, u32 addrs[2]);
 };
 
 static inline struct aspeed_kcs_bmc *to_aspeed_kcs_bmc(struct kcs_bmc_device *kcs_bmc)
@@ -217,38 +224,64 @@ static void aspeed_kcs_updateb(struct kcs_bmc_device *kcs_bmc, u32 reg, u8 mask,
  *     C. KCS4
  *        D / C : CA4h / CA5h
  */
-static void aspeed_kcs_set_address(struct kcs_bmc_device *kcs_bmc, u16 addr)
+static int aspeed_kcs_set_address(struct kcs_bmc_device *kcs_bmc, u32 addrs[2], int nr_addrs)
 {
 	struct aspeed_kcs_bmc *priv = to_aspeed_kcs_bmc(kcs_bmc);
 
-	switch (kcs_bmc->channel) {
+	if (WARN_ON(nr_addrs < 1 || nr_addrs > 2))
+		return -EINVAL;
+
+	switch (priv->kcs_bmc.channel) {
 	case 1:
-		regmap_update_bits(priv->map, LPC_HICR4,
-				LPC_HICR4_LADR12AS, 0);
-		regmap_write(priv->map, LPC_LADR12H, addr >> 8);
-		regmap_write(priv->map, LPC_LADR12L, addr & 0xFF);
+		regmap_update_bits(priv->map, LPC_HICR4, LPC_HICR4_LADR12AS, 0);
+		regmap_write(priv->map, LPC_LADR12H, addrs[0] >> 8);
+		regmap_write(priv->map, LPC_LADR12L, addrs[0] & 0xFF);
+		if (nr_addrs == 2) {
+			regmap_update_bits(priv->map, LPC_LSADR12, LPC_LSADR12_LSADR1_MASK,
+					   addrs[1] << LPC_LSADR12_LSADR1_SHIFT);
+
+			regmap_update_bits(priv->map, LPC_HICRB, LPC_HICRB_EN16LADR1,
+					   LPC_HICRB_EN16LADR1);
+		}
 		break;
 
 	case 2:
-		regmap_update_bits(priv->map, LPC_HICR4,
-				LPC_HICR4_LADR12AS, LPC_HICR4_LADR12AS);
-		regmap_write(priv->map, LPC_LADR12H, addr >> 8);
-		regmap_write(priv->map, LPC_LADR12L, addr & 0xFF);
+		regmap_update_bits(priv->map, LPC_HICR4, LPC_HICR4_LADR12AS, LPC_HICR4_LADR12AS);
+		regmap_write(priv->map, LPC_LADR12H, addrs[0] >> 8);
+		regmap_write(priv->map, LPC_LADR12L, addrs[0] & 0xFF);
+		if (nr_addrs == 2) {
+			regmap_update_bits(priv->map, LPC_LSADR12, LPC_LSADR12_LSADR2_MASK,
+					   addrs[1] << LPC_LSADR12_LSADR2_SHIFT);
+
+			regmap_update_bits(priv->map, LPC_HICRB, LPC_HICRB_EN16LADR2,
+					   LPC_HICRB_EN16LADR2);
+		}
 		break;
 
 	case 3:
-		regmap_write(priv->map, LPC_LADR3H, addr >> 8);
-		regmap_write(priv->map, LPC_LADR3L, addr & 0xFF);
+		if (nr_addrs == 2) {
+			dev_err(priv->kcs_bmc.dev,
+				"Channel 3 only supports inferred status IO address\n");
+			return -EINVAL;
+		}
+
+		regmap_write(priv->map, LPC_LADR3H, addrs[0] >> 8);
+		regmap_write(priv->map, LPC_LADR3L, addrs[0] & 0xFF);
 		break;
 
 	case 4:
-		regmap_write(priv->map, LPC_LADR4, ((addr + 1) << 16) |
-			addr);
+		if (nr_addrs == 1)
+			regmap_write(priv->map, LPC_LADR4, ((addrs[0] + 1) << 16) | addrs[0]);
+		else
+			regmap_write(priv->map, LPC_LADR4, (addrs[1] << 16) | addrs[0]);
+
 		break;
 
 	default:
-		break;
+		return -EINVAL;
 	}
+
+	return 0;
 }
 
 static inline int aspeed_kcs_map_serirq_type(u32 dt_type)
@@ -457,18 +490,18 @@ static int aspeed_kcs_of_v1_get_channel(struct platform_device *pdev)
 	return channel;
 }
 
-static int aspeed_kcs_of_v1_get_io_address(struct platform_device *pdev)
+static int
+aspeed_kcs_of_v1_get_io_address(struct platform_device *pdev, u32 addrs[2])
 {
-	u32 slave;
 	int rc;
 
-	rc = of_property_read_u32(pdev->dev.of_node, "kcs_addr", &slave);
-	if (rc || slave > 0xffff) {
+	rc = of_property_read_u32(pdev->dev.of_node, "kcs_addr", addrs);
+	if (rc || addrs[0] > 0xffff) {
 		dev_err(&pdev->dev, "no valid 'kcs_addr' configured\n");
 		return -EINVAL;
 	}
 
-	return slave;
+	return 1;
 }
 
 static int aspeed_kcs_of_v2_get_channel(struct platform_device *pdev)
@@ -504,18 +537,30 @@ static int aspeed_kcs_of_v2_get_channel(struct platform_device *pdev)
 	return -EINVAL;
 }
 
-static int aspeed_kcs_of_v2_get_io_address(struct platform_device *pdev)
+static int
+aspeed_kcs_of_v2_get_io_address(struct platform_device *pdev, u32 addrs[2])
 {
-	uint32_t slave;
 	int rc;
 
-	rc = of_property_read_u32(pdev->dev.of_node, "aspeed,lpc-io-reg", &slave);
-	if (rc || slave > 0xffff) {
-		dev_err(&pdev->dev, "no valid 'aspeed,lpc-io-reg' configured\n");
+	rc = of_property_read_variable_u32_array(pdev->dev.of_node,
+						 "aspeed,lpc-io-reg",
+						 addrs, 1, 2);
+	if (rc < 0) {
+		dev_err(&pdev->dev, "No valid 'aspeed,lpc-io-reg' configured\n");
+		return rc;
+	}
+
+	if (addrs[0] > 0xffff) {
+		dev_err(&pdev->dev, "Invalid data address in 'aspeed,lpc-io-reg'\n");
+		return -EINVAL;
+	}
+
+	if (rc == 2 && addrs[1] > 0xffff) {
+		dev_err(&pdev->dev, "Invalid status address in 'aspeed,lpc-io-reg'\n");
 		return -EINVAL;
 	}
 
-	return slave;
+	return rc;
 }
 
 static int aspeed_kcs_probe(struct platform_device *pdev)
@@ -524,9 +569,11 @@ static int aspeed_kcs_probe(struct platform_device *pdev)
 	struct kcs_bmc_device *kcs_bmc;
 	struct aspeed_kcs_bmc *priv;
 	struct device_node *np;
-	int rc, channel, addr;
 	bool have_upstream_irq;
 	u32 upstream_irq[2];
+	int rc, channel;
+	int nr_addrs;
+	u32 addrs[2];
 
 	np = pdev->dev.of_node->parent;
 	if (!of_device_is_compatible(np, "aspeed,ast2400-lpc-v2") &&
@@ -544,9 +591,9 @@ static int aspeed_kcs_probe(struct platform_device *pdev)
 	if (channel < 0)
 		return channel;
 
-	addr = ops->get_io_address(pdev);
-	if (addr < 0)
-		return addr;
+	nr_addrs = ops->get_io_address(pdev, addrs);
+	if (nr_addrs < 0)
+		return nr_addrs;
 
 	np = pdev->dev.of_node;
 	rc = of_property_read_u32_array(np, "aspeed,lpc-interrupts", upstream_irq, 2);
@@ -575,7 +622,9 @@ static int aspeed_kcs_probe(struct platform_device *pdev)
 	priv->obe.remove = false;
 	timer_setup(&priv->obe.timer, aspeed_kcs_check_obe, 0);
 
-	aspeed_kcs_set_address(kcs_bmc, addr);
+	rc = aspeed_kcs_set_address(kcs_bmc, addrs, nr_addrs);
+	if (rc)
+		return rc;
 
 	/* Host to BMC IRQ */
 	rc = aspeed_kcs_config_downstream_irq(kcs_bmc, pdev);
@@ -602,7 +651,8 @@ static int aspeed_kcs_probe(struct platform_device *pdev)
 		return rc;
 	}
 
-	dev_info(&pdev->dev, "Initialised channel %d at 0x%x\n", kcs_bmc->channel, addr);
+	dev_info(&pdev->dev, "Initialised channel %d at 0x%x\n",
+			kcs_bmc->channel, addrs[0]);
 
 	return 0;
 }
-- 
2.30.2


^ permalink raw reply related	[flat|nested] 23+ messages in thread

* Re: [PATCH v4 00/16] ipmi: Allow raw access to KCS devices
  2021-06-08 10:47 [PATCH v4 00/16] ipmi: Allow raw access to KCS devices Andrew Jeffery
                   ` (15 preceding siblings ...)
  2021-06-08 10:47 ` [PATCH v4 16/16] ipmi: kcs_bmc_aspeed: Optionally apply status address Andrew Jeffery
@ 2021-06-15 18:46 ` Corey Minyard
  2021-06-15 22:43   ` Andrew Jeffery
  16 siblings, 1 reply; 23+ messages in thread
From: Corey Minyard @ 2021-06-15 18:46 UTC (permalink / raw)
  To: Andrew Jeffery
  Cc: openipmi-developer, openbmc, devicetree, tmaimon77, linux-aspeed,
	avifishman70, venture, linux-kernel, tali.perry1, robh+dt,
	chiawei_wang, linux-arm-kernel, benjaminfair, arnd, zweiss, joel,
	KWLIU

On Tue, Jun 08, 2021 at 08:17:41PM +0930, Andrew Jeffery wrote:
> 
> Hello,
> 
> This is the 4th spin of the series refactoring the keyboard-controller-style
> device drivers in the IPMI subsystem.

Ok, no comments and everything looks good, I have this queued for the
next Linux release.

Thanks,

-corey

> 
> v3 can be found at:
> 
> https://lore.kernel.org/lkml/20210510054213.1610760-1-andrew@aj.id.au/
> 
> v4:
> 
> * Makes kcs_bmc_add_device() return an error if no client successfully
>   initialised with respect to the binding of the device driver
> * Retains the existing single-open semantics (v3 allowed multiple-open)
> * Fixes the OBE macro for the NPCM7xx KCS driver
> * Cleans up Yoda-style masks (mask constant on the LHS rather than RHS)
> * Cleans up includes in kcs_bmc_client.h
> * Adds some comments to the SerIO adapter to clarify object lifetimes
> 
> Previously:
> 
> Changes in v3:
> 
> * The series was rebased onto v5.13-rc1
> * v5.13-rc1 includes Chiawei's patches reworking the LPC devicetree bindings,
>   so they're no-longer required in the series.
> * After some discussion with Arnd[1] and investigating the serio subsystem,
>   I've replaced the "raw" KCS driver (patch 16/21 in v2) with a serio adaptor
>   (patch 11/16 in this series). The adaptor allows us to take advantage of the
>   existing chardevs provided by serio.
> 
> [1] https://lore.kernel.org/linux-arm-kernel/37e75b07-a5c6-422f-84b3-54f2bea0b917@www.fastmail.com/
> 
> Changes in v2 include:
> 
> * A rebase onto v5.12-rc2
> * Incorporation of off-list feedback on SerIRQ configuration from
>   Chiawei
> * Further validation on hardware for ASPEED KCS devices 2, 3 and 4
> * Lifting the existing single-open constraint of the IPMI chardev
> * Fixes addressing Rob's feedback on the conversion of the ASPEED KCS
>   binding to dt-schema
> * Fixes addressing Rob's feedback on the new aspeed,lpc-interrupts
>   property definition for the ASPEED KCS binding
> 
> Please test and review!
> 
> Andrew
> 
> Andrew Jeffery (16):
>   ipmi: kcs_bmc_aspeed: Use of match data to extract KCS properties
>   ipmi: kcs_bmc: Make status update atomic
>   ipmi: kcs_bmc: Rename {read,write}_{status,data}() functions
>   ipmi: kcs_bmc: Split out kcs_bmc_cdev_ipmi
>   ipmi: kcs_bmc: Turn the driver data-structures inside-out
>   ipmi: kcs_bmc: Split headers into device and client
>   ipmi: kcs_bmc: Strip private client data from struct kcs_bmc
>   ipmi: kcs_bmc: Decouple the IPMI chardev from the core
>   ipmi: kcs_bmc: Allow clients to control KCS IRQ state
>   ipmi: kcs_bmc: Enable IBF on open
>   ipmi: kcs_bmc: Add serio adaptor
>   dt-bindings: ipmi: Convert ASPEED KCS binding to schema
>   dt-bindings: ipmi: Add optional SerIRQ property to ASPEED KCS devices
>   ipmi: kcs_bmc_aspeed: Implement KCS SerIRQ configuration
>   ipmi: kcs_bmc_aspeed: Fix IBFIE typo from datasheet
>   ipmi: kcs_bmc_aspeed: Optionally apply status address
> 
>  .../bindings/ipmi/aspeed,ast2400-kcs-bmc.yaml | 106 +++
>  .../bindings/ipmi/aspeed-kcs-bmc.txt          |  33 -
>  drivers/char/ipmi/Kconfig                     |  27 +
>  drivers/char/ipmi/Makefile                    |   2 +
>  drivers/char/ipmi/kcs_bmc.c                   | 523 ++++-----------
>  drivers/char/ipmi/kcs_bmc.h                   |  92 +--
>  drivers/char/ipmi/kcs_bmc_aspeed.c            | 633 +++++++++++++-----
>  drivers/char/ipmi/kcs_bmc_cdev_ipmi.c         | 568 ++++++++++++++++
>  drivers/char/ipmi/kcs_bmc_client.h            |  45 ++
>  drivers/char/ipmi/kcs_bmc_device.h            |  22 +
>  drivers/char/ipmi/kcs_bmc_npcm7xx.c           |  92 ++-
>  drivers/char/ipmi/kcs_bmc_serio.c             | 157 +++++
>  12 files changed, 1594 insertions(+), 706 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/ipmi/aspeed,ast2400-kcs-bmc.yaml
>  delete mode 100644 Documentation/devicetree/bindings/ipmi/aspeed-kcs-bmc.txt
>  create mode 100644 drivers/char/ipmi/kcs_bmc_cdev_ipmi.c
>  create mode 100644 drivers/char/ipmi/kcs_bmc_client.h
>  create mode 100644 drivers/char/ipmi/kcs_bmc_device.h
>  create mode 100644 drivers/char/ipmi/kcs_bmc_serio.c
> 
> -- 
> 2.30.2
> 

^ permalink raw reply	[flat|nested] 23+ messages in thread

* Re: [PATCH v4 00/16] ipmi: Allow raw access to KCS devices
  2021-06-15 18:46 ` [PATCH v4 00/16] ipmi: Allow raw access to KCS devices Corey Minyard
@ 2021-06-15 22:43   ` Andrew Jeffery
  0 siblings, 0 replies; 23+ messages in thread
From: Andrew Jeffery @ 2021-06-15 22:43 UTC (permalink / raw)
  To: Corey Minyard
  Cc: openipmi-developer, openbmc, devicetree, Tomer Maimon,
	linux-aspeed, Avi Fishman, Patrick Venture, linux-kernel,
	Tali Perry, Rob Herring, Chia-Wei, Wang, linux-arm-kernel,
	Benjamin Fair, Arnd Bergmann, Zev Weiss, Joel Stanley,
	CS20 KWLiu



On Wed, 16 Jun 2021, at 04:16, Corey Minyard wrote:
> On Tue, Jun 08, 2021 at 08:17:41PM +0930, Andrew Jeffery wrote:
> > 
> > Hello,
> > 
> > This is the 4th spin of the series refactoring the keyboard-controller-style
> > device drivers in the IPMI subsystem.
> 
> Ok, no comments and everything looks good, I have this queued for the
> next Linux release.

Thanks!

Andrew

^ permalink raw reply	[flat|nested] 23+ messages in thread

* Re: [PATCH v4 01/16] ipmi: kcs_bmc_aspeed: Use of match data to extract KCS properties
  2021-06-08 10:47 ` [PATCH v4 01/16] ipmi: kcs_bmc_aspeed: Use of match data to extract KCS properties Andrew Jeffery
@ 2021-06-18 23:19   ` Zev Weiss
  0 siblings, 0 replies; 23+ messages in thread
From: Zev Weiss @ 2021-06-18 23:19 UTC (permalink / raw)
  To: Andrew Jeffery
  Cc: openipmi-developer, openbmc, minyard, devicetree, tmaimon77,
	linux-aspeed, avifishman70, venture, linux-kernel, tali.perry1,
	robh+dt, chiawei_wang, linux-arm-kernel, benjaminfair, arnd,
	joel, KWLIU

On Tue, Jun 08, 2021 at 05:47:42AM 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 | 154 ++++++++++++++---------------
> 1 file changed, 77 insertions(+), 77 deletions(-)
>

Reviewed-by: Zev Weiss <zweiss@equinix.com>

^ permalink raw reply	[flat|nested] 23+ messages in thread

* Re: [PATCH v4 06/16] ipmi: kcs_bmc: Split headers into device and client
  2021-06-08 10:47 ` [PATCH v4 06/16] ipmi: kcs_bmc: Split headers into device and client Andrew Jeffery
@ 2021-06-18 23:24   ` Zev Weiss
  0 siblings, 0 replies; 23+ messages in thread
From: Zev Weiss @ 2021-06-18 23:24 UTC (permalink / raw)
  To: Andrew Jeffery
  Cc: openipmi-developer, openbmc, minyard, devicetree, tmaimon77,
	linux-aspeed, avifishman70, venture, linux-kernel, tali.perry1,
	robh+dt, chiawei_wang, linux-arm-kernel, benjaminfair, arnd,
	joel, KWLIU

On Tue, Jun 08, 2021 at 05:47:47AM CDT, Andrew Jeffery wrote:
>Strengthen the distinction between code that abstracts the
>implementation of the KCS behaviours (device drivers) and code that
>exploits KCS behaviours (clients). Neither needs to know about the APIs
>required by the other, so provide separate headers.
>
>Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
>---
> drivers/char/ipmi/kcs_bmc.c           | 23 ++++++++++------
> drivers/char/ipmi/kcs_bmc.h           | 27 +++++++++----------
> drivers/char/ipmi/kcs_bmc_aspeed.c    | 17 ++++++------
> drivers/char/ipmi/kcs_bmc_cdev_ipmi.c | 39 ++++++++++++++++++---------
> drivers/char/ipmi/kcs_bmc_client.h    | 27 +++++++++++++++++++
> drivers/char/ipmi/kcs_bmc_device.h    | 19 +++++++++++++
> drivers/char/ipmi/kcs_bmc_npcm7xx.c   | 17 ++++++------
> 7 files changed, 117 insertions(+), 52 deletions(-)
> create mode 100644 drivers/char/ipmi/kcs_bmc_client.h
> create mode 100644 drivers/char/ipmi/kcs_bmc_device.h
>

Reviewed-by: Zev Weiss <zweiss@equinix.com>

^ permalink raw reply	[flat|nested] 23+ messages in thread

* Re: [PATCH v4 08/16] ipmi: kcs_bmc: Decouple the IPMI chardev from the core
  2021-06-08 10:47 ` [PATCH v4 08/16] ipmi: kcs_bmc: Decouple the IPMI chardev from the core Andrew Jeffery
@ 2021-06-18 23:26   ` Zev Weiss
  0 siblings, 0 replies; 23+ messages in thread
From: Zev Weiss @ 2021-06-18 23:26 UTC (permalink / raw)
  To: Andrew Jeffery
  Cc: openipmi-developer, openbmc, minyard, devicetree, tmaimon77,
	linux-aspeed, avifishman70, venture, linux-kernel, tali.perry1,
	robh+dt, chiawei_wang, linux-arm-kernel, benjaminfair, arnd,
	joel, KWLIU

On Tue, Jun 08, 2021 at 05:47:49AM CDT, Andrew Jeffery wrote:
>Now that we have untangled the data-structures, split the userspace
>interface out into its own module. Userspace interfaces and drivers are
>registered to the KCS BMC core to support arbitrary binding of either.
>
>Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
>---
> drivers/char/ipmi/Kconfig             | 13 +++++
> drivers/char/ipmi/Makefile            |  3 +-
> drivers/char/ipmi/kcs_bmc.c           | 80 +++++++++++++++++++++++++--
> drivers/char/ipmi/kcs_bmc_cdev_ipmi.c | 31 +++++++++--
> drivers/char/ipmi/kcs_bmc_client.h    | 14 +++++
> 5 files changed, 128 insertions(+), 13 deletions(-)
>

Reviewed-by: Zev Weiss <zweiss@equinix.com>

^ permalink raw reply	[flat|nested] 23+ messages in thread

* Re: [PATCH v4 11/16] ipmi: kcs_bmc: Add serio adaptor
  2021-06-08 10:47 ` [PATCH v4 11/16] ipmi: kcs_bmc: Add serio adaptor Andrew Jeffery
@ 2021-06-18 23:30   ` Zev Weiss
  0 siblings, 0 replies; 23+ messages in thread
From: Zev Weiss @ 2021-06-18 23:30 UTC (permalink / raw)
  To: Andrew Jeffery
  Cc: openipmi-developer, openbmc, minyard, devicetree, tmaimon77,
	linux-aspeed, avifishman70, venture, linux-kernel, tali.perry1,
	robh+dt, chiawei_wang, linux-arm-kernel, benjaminfair, arnd,
	joel, KWLIU

On Tue, Jun 08, 2021 at 05:47:52AM CDT, Andrew Jeffery wrote:
>kcs_bmc_serio acts as a bridge between the KCS drivers in the IPMI
>subsystem and the existing userspace interfaces available through the
>serio subsystem. This is useful when userspace would like to make use of
>the BMC KCS devices for purposes that aren't IPMI.
>
>Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
>---
> drivers/char/ipmi/Kconfig         |  14 +++
> drivers/char/ipmi/Makefile        |   1 +
> drivers/char/ipmi/kcs_bmc_serio.c | 157 ++++++++++++++++++++++++++++++
> 3 files changed, 172 insertions(+)
> create mode 100644 drivers/char/ipmi/kcs_bmc_serio.c
>

Reviewed-by: Zev Weiss <zweiss@equinix.com>

^ permalink raw reply	[flat|nested] 23+ messages in thread

end of thread, other threads:[~2021-06-19  1:21 UTC | newest]

Thread overview: 23+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-06-08 10:47 [PATCH v4 00/16] ipmi: Allow raw access to KCS devices Andrew Jeffery
2021-06-08 10:47 ` [PATCH v4 01/16] ipmi: kcs_bmc_aspeed: Use of match data to extract KCS properties Andrew Jeffery
2021-06-18 23:19   ` Zev Weiss
2021-06-08 10:47 ` [PATCH v4 02/16] ipmi: kcs_bmc: Make status update atomic Andrew Jeffery
2021-06-08 10:47 ` [PATCH v4 03/16] ipmi: kcs_bmc: Rename {read,write}_{status,data}() functions Andrew Jeffery
2021-06-08 10:47 ` [PATCH v4 04/16] ipmi: kcs_bmc: Split out kcs_bmc_cdev_ipmi Andrew Jeffery
2021-06-08 10:47 ` [PATCH v4 05/16] ipmi: kcs_bmc: Turn the driver data-structures inside-out Andrew Jeffery
2021-06-08 10:47 ` [PATCH v4 06/16] ipmi: kcs_bmc: Split headers into device and client Andrew Jeffery
2021-06-18 23:24   ` Zev Weiss
2021-06-08 10:47 ` [PATCH v4 07/16] ipmi: kcs_bmc: Strip private client data from struct kcs_bmc Andrew Jeffery
2021-06-08 10:47 ` [PATCH v4 08/16] ipmi: kcs_bmc: Decouple the IPMI chardev from the core Andrew Jeffery
2021-06-18 23:26   ` Zev Weiss
2021-06-08 10:47 ` [PATCH v4 09/16] ipmi: kcs_bmc: Allow clients to control KCS IRQ state Andrew Jeffery
2021-06-08 10:47 ` [PATCH v4 10/16] ipmi: kcs_bmc: Enable IBF on open Andrew Jeffery
2021-06-08 10:47 ` [PATCH v4 11/16] ipmi: kcs_bmc: Add serio adaptor Andrew Jeffery
2021-06-18 23:30   ` Zev Weiss
2021-06-08 10:47 ` [PATCH v4 12/16] dt-bindings: ipmi: Convert ASPEED KCS binding to schema Andrew Jeffery
2021-06-08 10:47 ` [PATCH v4 13/16] dt-bindings: ipmi: Add optional SerIRQ property to ASPEED KCS devices Andrew Jeffery
2021-06-08 10:47 ` [PATCH v4 14/16] ipmi: kcs_bmc_aspeed: Implement KCS SerIRQ configuration Andrew Jeffery
2021-06-08 10:47 ` [PATCH v4 15/16] ipmi: kcs_bmc_aspeed: Fix IBFIE typo from datasheet Andrew Jeffery
2021-06-08 10:47 ` [PATCH v4 16/16] ipmi: kcs_bmc_aspeed: Optionally apply status address Andrew Jeffery
2021-06-15 18:46 ` [PATCH v4 00/16] ipmi: Allow raw access to KCS devices Corey Minyard
2021-06-15 22:43   ` Andrew Jeffery

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