Re [PATCH v2 21/21] ipmi: kcs_bmc_aspeed: Optionally apply status address

Zev Weiss
2021-04-01T18:18:09Z

On Fri, Mar 19, 2021 at 01:27:52AM CDT, Andrew Jeffery wrote:
>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>
>---
> drivers/char/ipmi/kcs_bmc_aspeed.c | 113 +++++++++++++++++++++--------
> 1 file changed, 81 insertions(+), 32 deletions(-)
>
>diff --git a/drivers/char/ipmi/kcs_bmc_aspeed.c b/drivers/char/ipmi/kcs_bmc_aspeed.c
>index 7334b1f51dcc..98789b837690 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)
>@@ -462,18 +495,18 @@ 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)
>@@ -509,16 +542,27 @@ 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)
>+ rc = of_property_read_variable_u32_array(pdev->dev.of_node,
>+ "aspeed,lpc-io-reg",
>+ addrs, 1, 2);
>+ if (rc < 0)
>+ return rc;
>+
>+ if (WARN_ON(rc == 0))
>+ return -EINVAL;

Is this check necessary? It looks like
of_property_read_variable_u32_array() should fail in that case given
sz_min==1, so this seems like it should be impossible to trigger.

>+
>+ if (addrs[0] > 0xffff)
>+ return -EINVAL;
>+
>+ if (rc == 2 && addrs[1] > 0xffff)
> return -EINVAL;
>
>- return slave;
>+ return rc;
> }
>
> static int aspeed_kcs_probe(struct platform_device *pdev)
>@@ -527,9 +571,11 @@ 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") &&
>@@ -547,9 +593,9 @@ 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);
>@@ -578,7 +624,9 @@ 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);
>@@ -600,7 +648,8 @@ static int aspeed_kcs_probe(struct platform_device *pdev)
> if (rc < 0)
> 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;
> }
>--
>2.27.0
>