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

Zev Weiss
2021-04-01T10:28:38Z

On Fri, Mar 19, 2021 at 01:27:50AM CDT, Andrew Jeffery wrote:
>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]);

This has a return value that could indicate an error if the DT
properties are misconfigured; do we want to check for that here?

>+ 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
>