[PATCH v3 3/8] mfd: khadas-mcu: Add per-variant configuration infrastructure and VIM4 support

Ronald Claveau
2026-04-17T16:37:17Z

Introduce a per-variant configuration structure (khadas_mcu_data)
holding the regmap config and MFD cells,
selected at probe time via the of_device_id match data.
This makes adding other variants straightforward.

Also introduce khadas_mcu_fan_pdata to pass fan register address and
maximum level to the fan sub-driver, removing the hardcoded constants.

Signed-off-by: Ronald Claveau <linux-kernel-dev@aliel.fr>
---
include/linux/mfd/khadas-mcu.h | 39 +++++++++++++++++++++++++++++++++++++--
1 file changed, 37 insertions(+), 2 deletions(-)

diff --git a/include/linux/mfd/khadas-mcu.h b/include/linux/mfd/khadas-mcu.h
index a99ba2ed0e4e0..75e275d3fa8d9 100644
--- a/include/linux/mfd/khadas-mcu.h
+++ b/include/linux/mfd/khadas-mcu.h
@@ -70,6 +70,13 @@
#define KHADAS_MCU_WOL_INIT_START_REG 0x87 /* WO */
#define KHADAS_MCU_CMD_FAN_STATUS_CTRL_REG 0x88 /* WO */

+/* VIM4 specific registers */
+#define KHADAS_MCU_VIM4_REST_CONF_REG 0x2c /* WO - reset EEPROM */
+#define KHADAS_MCU_VIM4_LED_ON_RAM_REG 0x89 /* WO - LED volatile */
+#define KHADAS_MCU_VIM4_FAN_CTRL_REG 0x8a /* WO */
+#define KHADAS_MCU_VIM4_WDT_EN_REG 0x8b /* WO */
+#define KHADAS_MCU_VIM4_SYS_RST_REG 0x91 /* WO */
+
enum {
KHADAS_BOARD_VIM1 = 0x1,
KHADAS_BOARD_VIM2,
@@ -82,10 +89,38 @@ enum {
* struct khadas_mcu - Khadas MCU structure
* @device: device reference used for logs
* @regmap: register map
+ * @data: pointer to variant-specific config
*/
struct khadas_mcu {
- struct device *dev;
- struct regmap *regmap;
+ struct device *dev;
+ struct regmap *regmap;
+ const struct khadas_mcu_data *data;
+};
+
+/**
+ * struct khadas_mcu_data - per-variant configuration
+ * @regmap_config: regmap configuration
+ * @cells: MFD sub-devices
+ * @ncells: number of sub-devices
+ * @fan_cells: MFD fan sub-devices
+ * @nfan_cells: number of fan sub-devices
+ */
+struct khadas_mcu_data {
+ const struct regmap_config *regmap_config;
+ const struct mfd_cell *cells;
+ int ncells;
+ const struct mfd_cell *fan_cells;
+ int nfan_cells;
+};
+
+/**
+ * struct khadas_mcu_fan_pdata - fan sub-driver configuration
+ * @fan_reg: register address to write the fan level
+ * @max_level: maximum fan level
+ */
+struct khadas_mcu_fan_pdata {
+ unsigned int fan_reg;
+ unsigned int max_level;
};

#endif /* MFD_KHADAS_MCU_H */

--
2.49.0