platform/x86: mlx-platform: Add physical bus number auto detection
mlx-platform does not provide a bus number to i2c-mlxcpld, assuming it
is always one. On some x86 systems, other i2c drivers may probe before
i2c-mlxcpld, causing bus one to be busy.
Make mlx-platform determine which adapter number is free prior to
activating i2c-mlxpld, adjusting the mux base numbers accordingly.
Update the mlxreg-hotplug pdata similarly.
This adds an explicit mlx-platform build dependency on I2C, update the
Kconfig accordingly. Add the missing REGMAP dependency while we're at
it.
Signed-off-by: Vadim Pasternak <vadimp@mellanox.com>
[dvhart: Rewrite commit message more concisely]
[dvhart: Add build dependencies]
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>
diff --git a/drivers/platform/x86/mlx-platform.c b/drivers/platform/x86/mlx-platform.c
index 67f3c6d..7a0bd24 100644
--- a/drivers/platform/x86/mlx-platform.c
+++ b/drivers/platform/x86/mlx-platform.c
@@ -85,6 +85,12 @@
#define MLXPLAT_CPLD_FAN_MASK GENMASK(3, 0)
#define MLXPLAT_CPLD_FAN_NG_MASK GENMASK(5, 0)
+/* Default I2C parent bus number */
+#define MLXPLAT_CPLD_PHYS_ADAPTER_DEF_NR 1
+
+/* Maximum number of possible physical buses equipped on system */
+#define MLXPLAT_CPLD_MAX_PHYS_ADAPTER_NUM 16
+
/* Number of channels in group */
#define MLXPLAT_CPLD_GRP_CHNL_NUM 8
@@ -843,10 +849,48 @@ static const struct dmi_system_id mlxplat_dmi_table[] __initconst = {
MODULE_DEVICE_TABLE(dmi, mlxplat_dmi_table);
+static int mlxplat_mlxcpld_verify_bus_topology(int *nr)
+{
+ struct i2c_adapter *search_adap;
+ int shift, i;
+
+ /* Scan adapters from expected id to verify it is free. */
+ *nr = MLXPLAT_CPLD_PHYS_ADAPTER_DEF_NR;
+ for (i = MLXPLAT_CPLD_PHYS_ADAPTER_DEF_NR; i <
+ MLXPLAT_CPLD_MAX_PHYS_ADAPTER_NUM; i++) {
+ search_adap = i2c_get_adapter(i);
+ if (search_adap) {
+ i2c_put_adapter(search_adap);
+ continue;
+ }
+
+ /* Return if expected parent adapter is free. */
+ if (i == MLXPLAT_CPLD_PHYS_ADAPTER_DEF_NR)
+ return 0;
+ break;
+ }
+
+ /* Return with error if free id for adapter is not found. */
+ if (i == MLXPLAT_CPLD_MAX_PHYS_ADAPTER_NUM)
+ return -ENODEV;
+
+ /* Shift adapter ids, since expected parent adapter is not free. */
+ *nr = i;
+ for (i = 0; i < ARRAY_SIZE(mlxplat_mux_data); i++) {
+ shift = *nr - mlxplat_mux_data[i].parent;
+ mlxplat_mux_data[i].parent = *nr;
+ mlxplat_mux_data[i].base_nr += shift;
+ if (shift > 0)
+ mlxplat_hotplug->shift_nr = shift;
+ }
+
+ return 0;
+}
+
static int __init mlxplat_init(void)
{
struct mlxplat_priv *priv;
- int i, err;
+ int i, nr, err;
if (!dmi_check_system(mlxplat_dmi_table))
return -ENODEV;
@@ -866,7 +910,12 @@ static int __init mlxplat_init(void)
}
platform_set_drvdata(mlxplat_dev, priv);
- priv->pdev_i2c = platform_device_register_simple("i2c_mlxcpld", -1,
+ err = mlxplat_mlxcpld_verify_bus_topology(&nr);
+ if (nr < 0)
+ goto fail_alloc;
+
+ nr = (nr == MLXPLAT_CPLD_MAX_PHYS_ADAPTER_NUM) ? -1 : nr;
+ priv->pdev_i2c = platform_device_register_simple("i2c_mlxcpld", nr,
NULL, 0);
if (IS_ERR(priv->pdev_i2c)) {
err = PTR_ERR(priv->pdev_i2c);