[RFC 1/5] ipmi:bt-bmc: Separate out ASPEED specific bits

Signed-off-by: Anton Blanchard <redacted>
---
 .../devicetree/bindings/ipmi/ibt-bmc.txt      |  1 +
 drivers/char/ipmi/Kconfig                     |  8 ++-
 drivers/char/ipmi/bt-bmc.c                    | 69 +++++++++++++++++++
 3 files changed, 75 insertions(+), 3 deletions(-)

diff --git a/Documentation/devicetree/bindings/ipmi/ibt-bmc.txt b/Documentation/devicetree/bindings/ipmi/ibt-bmc.txt
index 78ee716a950e..1b661daf0193 100644
--- a/Documentation/devicetree/bindings/ipmi/ibt-bmc.txt
+++ b/Documentation/devicetree/bindings/ipmi/ibt-bmc.txt

@@ -9,6 +9,7 @@ Required properties:
 - compatible : should be one of
        "aspeed,ast2400-ibt-bmc"
        "aspeed,ast2500-ibt-bmc"
+       "ibm,microwatt-ibt-bmc"
 - reg: physical address and size of the registers

 Optional properties:

diff --git a/drivers/char/ipmi/Kconfig b/drivers/char/ipmi/Kconfig
index 8b2f0f675e5f..079302f4eef2 100644
--- a/drivers/char/ipmi/Kconfig
+++ b/drivers/char/ipmi/Kconfig

@@ -152,13 +152,15 @@ config IPMI_KCS_BMC_SERIO
          called kcs_bmc_serio.

 config BT_IPMI_BMC
-       depends on ARCH_ASPEED || COMPILE_TEST
+       depends on ARCH_ASPEED || PPC_MICROWATT || COMPILE_TEST
        depends on REGMAP && REGMAP_MMIO && MFD_SYSCON
        tristate "BT IPMI bmc driver"
        help
          Provides a driver for the BT (Block Transfer) IPMI interface
-         found on Aspeed SOCs (AST2400 and AST2500). The driver
-         implements the BMC side of the BT interface.
+         found on Aspeed SOCs (AST2400 and AST2500) as well as the OpenPOWER
+         LPC peripheral macro at
+         <https://github.com/OpenPOWERFoundation/lpcperipheral>
+         The driver implements the BMC side of the BT interface.

 config IPMB_DEVICE_INTERFACE
        tristate 'IPMB Interface handler'

diff --git a/drivers/char/ipmi/bt-bmc.c b/drivers/char/ipmi/bt-bmc.c
index b48e04405ac4..24327b57c60b 100644
--- a/drivers/char/ipmi/bt-bmc.c
+++ b/drivers/char/ipmi/bt-bmc.c

@@ -41,6 +41,11 @@
 #define   BT_CR2_IRQ_HBUSY     0x40
 #define ASPEED_BT_CR3  0xc

+#define MICROWATT_IRQ_MASK     0x0
+#define MICROWATT_IRQ_STATUS   0x4
+#define   IRQ_HOST_TO_BMC_ATTN 0x1
+#define   IRQ_HOST_NOT_BUSY    0x2
+
 #define BT_CTRL                0x10
 #define   BT_CTRL_B_BUSY               0x80
 #define   BT_CTRL_H_BUSY               0x40

@@ -395,6 +400,27 @@ static irqreturn_t aspeed_bt_bmc_irq(int irq, void *arg)
        return IRQ_HANDLED;
 }

+static irqreturn_t microwatt_bt_bmc_irq(int irq, void *arg)
+{
+       struct bt_bmc *bt_bmc = arg;
+       u32 reg;
+       int rc;
+
+       rc = regmap_read(bt_bmc->map, bt_bmc->offset + MICROWATT_IRQ_STATUS, &reg);
+       if (rc)
+               return IRQ_NONE;
+
+       /* Interrupt wasn't something we knew about */
+       if (!(reg & (IRQ_HOST_TO_BMC_ATTN | IRQ_HOST_NOT_BUSY)))
+               return IRQ_NONE;
+
+       /* ack all pending IRQs */
+       regmap_write(bt_bmc->map, bt_bmc->offset + MICROWATT_IRQ_STATUS, 0);
+
+       wake_up(&bt_bmc->queue);
+       return IRQ_HANDLED;
+}
+
 static int aspeed_bt_bmc_config_irq(struct bt_bmc *bt_bmc,
                             struct platform_device *pdev)
 {

@@ -446,6 +472,48 @@ static const struct bt_bmc_ops aspeed_bt_bmc_ops = {
        .enable_bt = aspeed_enable_bt,
 };

+static int microwatt_bt_bmc_config_irq(struct bt_bmc *bt_bmc,
+                            struct platform_device *pdev)
+{
+       struct device *dev = &pdev->dev;
+       int rc;
+
+       bt_bmc->irq = platform_get_irq_optional(pdev, 0);
+       if (bt_bmc->irq < 0)
+               return bt_bmc->irq;
+
+       rc = devm_request_irq(dev, bt_bmc->irq, microwatt_bt_bmc_irq, IRQF_SHARED,
+                             DEVICE_NAME, bt_bmc);
+       if (rc < 0) {
+               dev_warn(dev, "Unable to request IRQ %d\n", bt_bmc->irq);
+               bt_bmc->irq = rc;
+               return rc;
+       }
+
+       /*
+        * Configure the hardware to give us an interrupt whenever the H2B
+        * bit is set or the HBUSY bit is cleared.
+        *
+        * H2B will be asserted when the bmc has data for us; HBUSY
+        * will be cleared (along with B2H) when we can write the next
+        * message to the BT buffer
+        */
+       rc = regmap_update_bits(bt_bmc->map, bt_bmc->offset + MICROWATT_IRQ_MASK,
+                               (IRQ_HOST_TO_BMC_ATTN | IRQ_HOST_NOT_BUSY),
+                               (IRQ_HOST_TO_BMC_ATTN | IRQ_HOST_NOT_BUSY));
+
+       return rc;
+}
+
+static void microwatt_enable_bt(struct bt_bmc *bt_bmc)
+{
+}
+
+static const struct bt_bmc_ops microwatt_bt_bmc_ops = {
+       .config_irq = microwatt_bt_bmc_config_irq,
+       .enable_bt = microwatt_enable_bt,
+};
+
 static int bt_bmc_probe(struct platform_device *pdev)
 {
        struct bt_bmc *bt_bmc;

@@ -530,6 +598,7 @@ static int bt_bmc_remove(struct platform_device *pdev)
 static const struct of_device_id bt_bmc_match[] = {
        { .compatible = "aspeed,ast2400-ibt-bmc", .data = &aspeed_bt_bmc_ops },
        { .compatible = "aspeed,ast2500-ibt-bmc", .data = &aspeed_bt_bmc_ops },
+       { .compatible = "ibm,microwatt-ibt-bmc", .data = &microwatt_bt_bmc_ops },
        { },
 };

--

2.31.1

---
  drivers/char/ipmi/bt-bmc.c | 24 ++++++++++++++++++++----
  1 file changed, 20 insertions(+), 4 deletions(-)

diff --git a/drivers/char/ipmi/bt-bmc.c b/drivers/char/ipmi/bt-bmc.c
index 2b0fe1255026..b48e04405ac4 100644
--- a/drivers/char/ipmi/bt-bmc.c
+++ b/drivers/char/ipmi/bt-bmc.c

@@ -17,6 +17,7 @@
  #include <linux/regmap.h>
  #include <linux/sched.h>
  #include <linux/timer.h>
+#include <linux/of_device.h>
  
  /*
   * This is a BMC device used to communicate to the host

@@ -435,15 +436,30 @@ static void aspeed_enable_bt(struct bt_bmc *bt_bmc)
  		     BT_CR0_ENABLE_IBT);
  }
  
+struct bt_bmc_ops {
+	int (*config_irq)(struct bt_bmc *bt_bmc, struct platform_device *pdev);
+	void (*enable_bt)(struct bt_bmc *bt_bmc);
+};
+
+static const struct bt_bmc_ops aspeed_bt_bmc_ops = {
+	.config_irq = aspeed_bt_bmc_config_irq,
+	.enable_bt = aspeed_enable_bt,
+};
+
  static int bt_bmc_probe(struct platform_device *pdev)
  {
  	struct bt_bmc *bt_bmc;
  	struct device *dev;
  	int rc;
+	const struct bt_bmc_ops *ops;
  
  	dev = &pdev->dev;
  	dev_info(dev, "Found bt bmc device\n");
  
+	ops = of_device_get_match_data(&pdev->dev);
+	if (!ops)
+		return -ENODEV;
+
  	bt_bmc = devm_kzalloc(dev, sizeof(*bt_bmc), GFP_KERNEL);
  	if (!bt_bmc)
  		return -ENOMEM;

@@ -483,7 +499,7 @@ static int bt_bmc_probe(struct platform_device *pdev)
  		return rc;
  	}
  
-	aspeed_bt_bmc_config_irq(bt_bmc, pdev);
+	ops->config_irq(bt_bmc, pdev);
  
  	if (bt_bmc->irq >= 0) {
  		dev_info(dev, "Using IRQ %d\n", bt_bmc->irq);

@@ -494,7 +510,7 @@ static int bt_bmc_probe(struct platform_device *pdev)
  		add_timer(&bt_bmc->poll_timer);
  	}
  
-	aspeed_enable_bt(bt_bmc);
+	ops->enable_bt(bt_bmc);
  
  	clr_b_busy(bt_bmc);
  

@@ -512,8 +528,8 @@ static int bt_bmc_remove(struct platform_device *pdev)
  }
  
  static const struct of_device_id bt_bmc_match[] = {
-	{ .compatible = "aspeed,ast2400-ibt-bmc" },
-	{ .compatible = "aspeed,ast2500-ibt-bmc" },
+	{ .compatible = "aspeed,ast2400-ibt-bmc", .data = &aspeed_bt_bmc_ops },
+	{ .compatible = "aspeed,ast2500-ibt-bmc", .data = &aspeed_bt_bmc_ops },
  	{ },
  };
  

This adds the Microwatt specific bits, including interrupt support.

Signed-off-by: Anton Blanchard <redacted>
---
  .../devicetree/bindings/ipmi/ibt-bmc.txt      |  1 +
  drivers/char/ipmi/Kconfig                     |  8 ++-
  drivers/char/ipmi/bt-bmc.c                    | 69 +++++++++++++++++++
  3 files changed, 75 insertions(+), 3 deletions(-)

diff --git a/Documentation/devicetree/bindings/ipmi/ibt-bmc.txt b/Documentation/devicetree/bindings/ipmi/ibt-bmc.txt
index 78ee716a950e..1b661daf0193 100644
--- a/Documentation/devicetree/bindings/ipmi/ibt-bmc.txt
+++ b/Documentation/devicetree/bindings/ipmi/ibt-bmc.txt

@@ -9,6 +9,7 @@ Required properties:
  - compatible : should be one of
  	"aspeed,ast2400-ibt-bmc"
  	"aspeed,ast2500-ibt-bmc"
+	"ibm,microwatt-ibt-bmc"
  - reg: physical address and size of the registers
  
  Optional properties:

diff --git a/drivers/char/ipmi/Kconfig b/drivers/char/ipmi/Kconfig
index 8b2f0f675e5f..079302f4eef2 100644
--- a/drivers/char/ipmi/Kconfig
+++ b/drivers/char/ipmi/Kconfig

@@ -152,13 +152,15 @@ config IPMI_KCS_BMC_SERIO
  	  called kcs_bmc_serio.
  
  config BT_IPMI_BMC
-	depends on ARCH_ASPEED || COMPILE_TEST
+	depends on ARCH_ASPEED || PPC_MICROWATT || COMPILE_TEST
  	depends on REGMAP && REGMAP_MMIO && MFD_SYSCON
  	tristate "BT IPMI bmc driver"
  	help
  	  Provides a driver for the BT (Block Transfer) IPMI interface
-	  found on Aspeed SOCs (AST2400 and AST2500). The driver
-	  implements the BMC side of the BT interface.
+	  found on Aspeed SOCs (AST2400 and AST2500) as well as the OpenPOWER
+	  LPC peripheral macro at
+	  <https://github.com/OpenPOWERFoundation/lpcperipheral>
+	  The driver implements the BMC side of the BT interface.
  
  config IPMB_DEVICE_INTERFACE
  	tristate 'IPMB Interface handler'

diff --git a/drivers/char/ipmi/bt-bmc.c b/drivers/char/ipmi/bt-bmc.c
index b48e04405ac4..24327b57c60b 100644
--- a/drivers/char/ipmi/bt-bmc.c
+++ b/drivers/char/ipmi/bt-bmc.c

@@ -41,6 +41,11 @@
  #define   BT_CR2_IRQ_HBUSY	0x40
  #define ASPEED_BT_CR3	0xc
  
+#define MICROWATT_IRQ_MASK	0x0
+#define MICROWATT_IRQ_STATUS	0x4
+#define   IRQ_HOST_TO_BMC_ATTN	0x1
+#define   IRQ_HOST_NOT_BUSY	0x2
+
  #define BT_CTRL		0x10
  #define   BT_CTRL_B_BUSY		0x80
  #define   BT_CTRL_H_BUSY		0x40

@@ -395,6 +400,27 @@ static irqreturn_t aspeed_bt_bmc_irq(int irq, void *arg)
  	return IRQ_HANDLED;
  }
  
+static irqreturn_t microwatt_bt_bmc_irq(int irq, void *arg)
+{
+	struct bt_bmc *bt_bmc = arg;
+	u32 reg;
+	int rc;
+
+	rc = regmap_read(bt_bmc->map, bt_bmc->offset + MICROWATT_IRQ_STATUS, &reg);
+	if (rc)
+		return IRQ_NONE;
+
+	/* Interrupt wasn't something we knew about */
+	if (!(reg & (IRQ_HOST_TO_BMC_ATTN | IRQ_HOST_NOT_BUSY)))
+		return IRQ_NONE;
+
+	/* ack all pending IRQs */
+	regmap_write(bt_bmc->map, bt_bmc->offset + MICROWATT_IRQ_STATUS, 0);
+
+	wake_up(&bt_bmc->queue);
+	return IRQ_HANDLED;
+}
+
  static int aspeed_bt_bmc_config_irq(struct bt_bmc *bt_bmc,
  			     struct platform_device *pdev)
  {

@@ -446,6 +472,48 @@ static const struct bt_bmc_ops aspeed_bt_bmc_ops = {
  	.enable_bt = aspeed_enable_bt,
  };
  
+static int microwatt_bt_bmc_config_irq(struct bt_bmc *bt_bmc,
+			     struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	int rc;
+
+	bt_bmc->irq = platform_get_irq_optional(pdev, 0);
+	if (bt_bmc->irq < 0)
+		return bt_bmc->irq;
+
+	rc = devm_request_irq(dev, bt_bmc->irq, microwatt_bt_bmc_irq, IRQF_SHARED,
+			      DEVICE_NAME, bt_bmc);
+	if (rc < 0) {
+		dev_warn(dev, "Unable to request IRQ %d\n", bt_bmc->irq);
+		bt_bmc->irq = rc;
+		return rc;
+	}
+
+	/*
+	 * Configure the hardware to give us an interrupt whenever the H2B
+	 * bit is set or the HBUSY bit is cleared.
+	 *
+	 * H2B will be asserted when the bmc has data for us; HBUSY
+	 * will be cleared (along with B2H) when we can write the next
+	 * message to the BT buffer
+	 */
+	rc = regmap_update_bits(bt_bmc->map, bt_bmc->offset + MICROWATT_IRQ_MASK,
+				(IRQ_HOST_TO_BMC_ATTN | IRQ_HOST_NOT_BUSY),
+				(IRQ_HOST_TO_BMC_ATTN | IRQ_HOST_NOT_BUSY));

+	return rc;
+}
+
+static void microwatt_enable_bt(struct bt_bmc *bt_bmc)
+{
+}
+
+static const struct bt_bmc_ops microwatt_bt_bmc_ops = {
+	.config_irq = microwatt_bt_bmc_config_irq,
+	.enable_bt = microwatt_enable_bt,
+};
+
  static int bt_bmc_probe(struct platform_device *pdev)
  {
  	struct bt_bmc *bt_bmc;

@@ -530,6 +598,7 @@ static int bt_bmc_remove(struct platform_device *pdev)
  static const struct of_device_id bt_bmc_match[] = {
  	{ .compatible = "aspeed,ast2400-ibt-bmc", .data = &aspeed_bt_bmc_ops },
  	{ .compatible = "aspeed,ast2500-ibt-bmc", .data = &aspeed_bt_bmc_ops },
+	{ .compatible = "ibm,microwatt-ibt-bmc", .data = &microwatt_bt_bmc_ops },
  	{ },
  };
  

---
  drivers/char/ipmi/bt-bmc.c | 26 ++++++++++++++++----------
  1 file changed, 16 insertions(+), 10 deletions(-)

diff --git a/drivers/char/ipmi/bt-bmc.c b/drivers/char/ipmi/bt-bmc.c
index 6e3d247b55d1..f85fafc96ef6 100644
--- a/drivers/char/ipmi/bt-bmc.c
+++ b/drivers/char/ipmi/bt-bmc.c

@@ -39,6 +39,7 @@
  #define   BT_CR2_IRQ_H2B	0x01
  #define   BT_CR2_IRQ_HBUSY	0x40
  #define BT_CR3		0xc
+
  #define BT_CTRL		0x10
  #define   BT_CTRL_B_BUSY		0x80
  #define   BT_CTRL_H_BUSY		0x40

@@ -372,7 +373,7 @@ static void poll_timer(struct timer_list *t)
  	add_timer(&bt_bmc->poll_timer);
  }
  
-static irqreturn_t bt_bmc_irq(int irq, void *arg)
+static irqreturn_t aspeed_bt_bmc_irq(int irq, void *arg)
  {
  	struct bt_bmc *bt_bmc = arg;
  	u32 reg;

@@ -393,7 +394,7 @@ static irqreturn_t bt_bmc_irq(int irq, void *arg)
  	return IRQ_HANDLED;
  }
  
-static int bt_bmc_config_irq(struct bt_bmc *bt_bmc,
+static int aspeed_bt_bmc_config_irq(struct bt_bmc *bt_bmc,
  			     struct platform_device *pdev)
  {
  	struct device *dev = &pdev->dev;

@@ -403,7 +404,7 @@ static int bt_bmc_config_irq(struct bt_bmc *bt_bmc,
  	if (bt_bmc->irq < 0)
  		return bt_bmc->irq;
  
-	rc = devm_request_irq(dev, bt_bmc->irq, bt_bmc_irq, IRQF_SHARED,
+	rc = devm_request_irq(dev, bt_bmc->irq, aspeed_bt_bmc_irq, IRQF_SHARED,
  			      DEVICE_NAME, bt_bmc);
  	if (rc < 0) {
  		dev_warn(dev, "Unable to request IRQ %d\n", bt_bmc->irq);

@@ -424,6 +425,16 @@ static int bt_bmc_config_irq(struct bt_bmc *bt_bmc,
  	return rc;
  }
  
+static void aspeed_enable_bt(struct bt_bmc *bt_bmc)
+{
+	regmap_write(bt_bmc->map, bt_bmc->offset + BT_CR0,
+		     (BT_IO_BASE << BT_CR0_IO_BASE) |
+		     (BT_IRQ << BT_CR0_IRQ) |
+		     BT_CR0_EN_CLR_SLV_RDP |
+		     BT_CR0_EN_CLR_SLV_WRP |
+		     BT_CR0_ENABLE_IBT);
+}
+
  static int bt_bmc_probe(struct platform_device *pdev)
  {
  	struct bt_bmc *bt_bmc;

@@ -472,7 +483,7 @@ static int bt_bmc_probe(struct platform_device *pdev)
  		return rc;
  	}
  
-	bt_bmc_config_irq(bt_bmc, pdev);
+	aspeed_bt_bmc_config_irq(bt_bmc, pdev);
  
  	if (bt_bmc->irq >= 0) {
  		dev_info(dev, "Using IRQ %d\n", bt_bmc->irq);

@@ -483,12 +494,7 @@ static int bt_bmc_probe(struct platform_device *pdev)
  		add_timer(&bt_bmc->poll_timer);
  	}
  
-	regmap_write(bt_bmc->map, bt_bmc->offset + BT_CR0,
-		     (BT_IO_BASE << BT_CR0_IO_BASE) |
-		     (BT_IRQ << BT_CR0_IRQ) |
-		     BT_CR0_EN_CLR_SLV_RDP |
-		     BT_CR0_EN_CLR_SLV_WRP |
-		     BT_CR0_ENABLE_IBT);
+	aspeed_enable_bt(bt_bmc);
  
  	clr_b_busy(bt_bmc);