[PATCH v2 19/21] ipmi: kcs_bmc_aspeed: Implement KCS SerIRQ configuration

Andrew Jeffery
2021-03-19T06:27:50Z

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 | 179 ++++++++++++++++++++++++++++-
1 file changed, 177 insertions(+), 2 deletions(-)

diff --git a/drivers/char/ipmi/kcs_bmc_aspeed.c b/drivers/char/ipmi/kcs_bmc_aspeed.c
index 271845eb2e26..3782aef4eb73 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);
@@ -267,7 +424,7 @@ static irqreturn_t aspeed_kcs_irq(int irq, void *arg)
return rc == KCS_BMC_EVENT_HANDLED ? IRQ_HANDLED : IRQ_NONE;
}

-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;
@@ -371,6 +528,8 @@ 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") &&
@@ -379,6 +538,7 @@ 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;
@@ -391,6 +551,13 @@ 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;
@@ -413,10 +580,17 @@ 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)
+ aspeed_kcs_config_upstream_irq(priv, upstream_irq[0], upstream_irq[1]);
+ 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);
@@ -481,4 +655,5 @@ 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");
--
2.27.0