* [PATCH v7 1/2] dt-bindings: mfd: x-powers: Add AC200
2026-08-11 23:11 [PATCH v7 0/2] mfd: add X-Powers AC200 support James Hilliard
@ 2026-08-11 23:11 ` James Hilliard
2026-08-11 23:22 ` sashiko-bot
2026-08-11 23:11 ` [PATCH v7 2/2] mfd: ac200: Add X-Powers AC200 support James Hilliard
1 sibling, 1 reply; 5+ messages in thread
From: James Hilliard @ 2026-08-11 23:11 UTC (permalink / raw)
To: Lee Jones, Arnd Bergmann, Rob Herring, Krzysztof Kozlowski,
Conor Dooley, James Hilliard
Cc: Andrew Lunn, Jagielski, Jedrzej, Andre Przywara, Chen-Yu Tsai,
Jernej Škrabec, linux-sunxi, mfd, devicetree, linux-kernel
The AC200 is an I2C-controlled mixed-signal companion IC containing
audio, video, RTC and Fast Ethernet PHY functions.
Describe the parent device and its shared input clock. The Ethernet PHY
is represented by a PHY package on its MDIO bus, with a phandle back to
this device for access to the package control registers, so it does not
require an MFD child node. Function-specific supplies belong to their
consumer bindings rather than the shared parent.
The input clock must run at 24 or 27 MHz when the Ethernet PHY is used,
matching the rates encoded by its documented clock selector.
Signed-off-by: James Hilliard <james.hilliard1@gmail.com>
---
.../devicetree/bindings/mfd/x-powers,ac200.yaml | 49 ++++++++++++++++++++++
1 file changed, 49 insertions(+)
diff --git a/Documentation/devicetree/bindings/mfd/x-powers,ac200.yaml b/Documentation/devicetree/bindings/mfd/x-powers,ac200.yaml
new file mode 100644
index 000000000000..609831b15c80
--- /dev/null
+++ b/Documentation/devicetree/bindings/mfd/x-powers,ac200.yaml
@@ -0,0 +1,49 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mfd/x-powers,ac200.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: X-Powers AC200 mixed-signal IC
+
+maintainers:
+ - James Hilliard <james.hilliard1@gmail.com>
+
+description:
+ The AC200 is a mixed-signal companion IC containing audio, video, RTC and
+ Fast Ethernet PHY functions. Its control registers are accessed over I2C.
+
+properties:
+ compatible:
+ const: x-powers,ac200
+
+ reg:
+ maxItems: 1
+
+ clocks:
+ maxItems: 1
+ description:
+ AC200 input clock. When using the Ethernet PHY, its configured rate must
+ be 24 or 27 MHz, matching the rates encoded by the documented EPHY clock
+ selector.
+
+required:
+ - compatible
+ - reg
+ - clocks
+
+additionalProperties: false
+
+examples:
+ - |
+ i2c {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ mixed-signal@10 {
+ compatible = "x-powers,ac200";
+ reg = <0x10>;
+ clocks = <&pwm 5>;
+ };
+ };
+...
--
2.53.0
^ permalink raw reply related [flat|nested] 5+ messages in thread* [PATCH v7 2/2] mfd: ac200: Add X-Powers AC200 support
2026-08-11 23:11 [PATCH v7 0/2] mfd: add X-Powers AC200 support James Hilliard
2026-08-11 23:11 ` [PATCH v7 1/2] dt-bindings: mfd: x-powers: Add AC200 James Hilliard
@ 2026-08-11 23:11 ` James Hilliard
2026-08-11 23:18 ` sashiko-bot
1 sibling, 1 reply; 5+ messages in thread
From: James Hilliard @ 2026-08-11 23:11 UTC (permalink / raw)
To: Lee Jones, Arnd Bergmann, Rob Herring, Krzysztof Kozlowski,
Conor Dooley, James Hilliard
Cc: Andrew Lunn, Jagielski, Jedrzej, Andre Przywara, Chen-Yu Tsai,
Jernej Škrabec, linux-sunxi, mfd, devicetree, linux-kernel
The X-Powers AC200 is a mixed-signal companion IC with a paged register
map accessed over I2C.
Enable the shared input clock and prevent its rate from changing. Match
the vendor driver's 40 ms wait before the first register access,
initialize the paged regmap, report the chip and package revision, and
apply common reset.
The Ethernet PHY link endpoint is independently enumerated on its MDIO
bus rather than created as an MFD platform child. Keep the regmap attached
to the AC200 I2C device so a separately enumerated function can resolve
that device, establish its required lifetime relationship and retrieve
the regmap from the provider.
Cache only the common page selector. Individual functions can reset
independently and invalidate their other registers without regmap's
knowledge, so leave all functional registers volatile.
Reset the chip during managed teardown and system shutdown.
Signed-off-by: James Hilliard <james.hilliard1@gmail.com>
---
drivers/mfd/Kconfig | 11 ++++
drivers/mfd/Makefile | 1 +
drivers/mfd/ac200.c | 163 +++++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 175 insertions(+)
diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index e4fd4572472f..cac3fff5aee9 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -205,6 +205,17 @@ config MFD_AC100
This driver include only the core APIs. You have to select individual
components like codecs or RTC under the corresponding menus.
+config MFD_AC200
+ tristate "X-Powers AC200"
+ depends on I2C
+ depends on OF
+ select REGMAP_I2C
+ help
+ Support for the X-Powers AC200 mixed-signal companion IC. The AC200
+ contains audio, video, RTC and Fast Ethernet PHY functions and is
+ co-packaged with some Allwinner H6 and H616 SoCs. This driver provides
+ the shared register access used by the individual function drivers.
+
config MFD_AXP20X
tristate
select MFD_CORE
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 72d3944b0ad8..f8101d2a9ce9 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -150,6 +150,7 @@ obj-$(CONFIG_MFD_DA9052_SPI) += da9052-spi.o
obj-$(CONFIG_MFD_DA9052_I2C) += da9052-i2c.o
obj-$(CONFIG_MFD_AC100) += ac100.o
+obj-$(CONFIG_MFD_AC200) += ac200.o
obj-$(CONFIG_MFD_AXP20X) += axp20x.o
obj-$(CONFIG_MFD_AXP20X_I2C) += axp20x-i2c.o
obj-$(CONFIG_MFD_AXP20X_RSB) += axp20x-rsb.o
diff --git a/drivers/mfd/ac200.c b/drivers/mfd/ac200.c
new file mode 100644
index 000000000000..0964e637afef
--- /dev/null
+++ b/drivers/mfd/ac200.c
@@ -0,0 +1,163 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * MFD core driver for the X-Powers AC200
+ *
+ * Copyright (C) 2019 Jernej Skrabec <jernej.skrabec@gmail.com>
+ * Copyright (C) 2026 James Hilliard <james.hilliard1@gmail.com>
+ *
+ * Based on the AC100 driver:
+ * Copyright (C) 2016 Chen-Yu Tsai
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+
+#define AC200_SYS_VERSION_REG 0x0000
+#define AC200_SYS_VERSION_PACKAGE_MASK GENMASK(15, 14)
+#define AC200_SYS_VERSION_CHIP_MASK GENMASK(11, 0)
+
+#define AC200_SYS_CONTROL_REG 0x0002
+#define AC200_SYS_CONTROL_CHIP_RESET_DEASSERT BIT(0)
+
+/* Interface register accessible from every register page. */
+#define AC200_TWI_REG_ADDR_H 0x00fe
+#define AC200_MAX_REG 0xa1f2
+
+struct ac200 {
+ struct regmap *regmap;
+};
+
+static const struct regmap_range_cfg ac200_range_cfg[] = {
+ {
+ .range_max = AC200_MAX_REG,
+ .selector_reg = AC200_TWI_REG_ADDR_H,
+ .selector_mask = 0xff,
+ .window_len = 256,
+ },
+};
+
+/*
+ * Each AC200 sub-block can reset independently, invalidating its register
+ * contents without regmap's knowledge. Cache only the common page selector;
+ * this avoids a selector read-modify-write for every access on the same page
+ * without ever returning stale functional-register values.
+ */
+static bool ac200_volatile_reg(struct device *dev, unsigned int reg)
+{
+ return reg != AC200_TWI_REG_ADDR_H;
+}
+
+static const struct regmap_config ac200_regmap_config = {
+ .name = "ac200",
+ .reg_bits = 8,
+ .reg_stride = 2,
+ .val_bits = 16,
+ .ranges = ac200_range_cfg,
+ .num_ranges = ARRAY_SIZE(ac200_range_cfg),
+ .max_register = AC200_MAX_REG,
+ .volatile_reg = ac200_volatile_reg,
+ .cache_type = REGCACHE_MAPLE,
+};
+
+static void ac200_disable(void *data)
+{
+ struct ac200 *ddata = data;
+
+ regmap_write(ddata->regmap, AC200_SYS_CONTROL_REG, 0);
+}
+
+static int ac200_probe(struct i2c_client *client)
+{
+ struct device *dev = &client->dev;
+ unsigned int version;
+ struct ac200 *ddata;
+ struct clk *clk;
+ int ret;
+
+ ddata = devm_kzalloc(dev, sizeof(*ddata), GFP_KERNEL);
+ if (!ddata)
+ return -ENOMEM;
+
+ clk = devm_clk_get_enabled(dev, NULL);
+ if (IS_ERR(clk))
+ return dev_err_probe(dev, PTR_ERR(clk),
+ "failed to enable input clock\n");
+
+ ret = devm_clk_rate_exclusive_get(dev, clk);
+ if (ret)
+ return dev_err_probe(dev, ret, "failed to lock clock rate\n");
+
+ ddata->regmap = devm_regmap_init_i2c(client, &ac200_regmap_config);
+ if (IS_ERR(ddata->regmap))
+ return dev_err_probe(dev, PTR_ERR(ddata->regmap),
+ "failed to initialize regmap\n");
+
+ i2c_set_clientdata(client, ddata);
+
+ /*
+ * No minimum delay is documented. Match the vendor driver's 40 ms delay
+ * before its first AC200 register access after enabling the input clock.
+ */
+ msleep(40);
+
+ ret = regmap_read(ddata->regmap, AC200_SYS_VERSION_REG, &version);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "failed to read chip version\n");
+
+ dev_info(dev, "AC200 revision %#lx in package %lu\n",
+ FIELD_GET(AC200_SYS_VERSION_CHIP_MASK, version),
+ FIELD_GET(AC200_SYS_VERSION_PACKAGE_MASK, version));
+
+ /* Reset the chip after dependent function drivers have unbound. */
+ ret = devm_add_action_or_reset(dev, ac200_disable, ddata);
+ if (ret)
+ return ret;
+
+ ret = regmap_write(ddata->regmap, AC200_SYS_CONTROL_REG, 0);
+ if (ret)
+ return ret;
+
+ ret = regmap_write(ddata->regmap, AC200_SYS_CONTROL_REG,
+ AC200_SYS_CONTROL_CHIP_RESET_DEASSERT);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+static void ac200_shutdown(struct i2c_client *client)
+{
+ ac200_disable(i2c_get_clientdata(client));
+}
+
+static const struct of_device_id ac200_of_match[] = {
+ { .compatible = "x-powers,ac200" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, ac200_of_match);
+
+static const struct i2c_device_id ac200_i2c_ids[] = {
+ { .name = "ac200" },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, ac200_i2c_ids);
+
+static struct i2c_driver ac200_driver = {
+ .driver = {
+ .name = "ac200",
+ .of_match_table = ac200_of_match,
+ },
+ .probe = ac200_probe,
+ .shutdown = ac200_shutdown,
+ .id_table = ac200_i2c_ids,
+};
+module_i2c_driver(ac200_driver);
+
+MODULE_AUTHOR("James Hilliard <james.hilliard1@gmail.com>");
+MODULE_DESCRIPTION("X-Powers AC200 MFD core driver");
+MODULE_LICENSE("GPL");
--
2.53.0
^ permalink raw reply related [flat|nested] 5+ messages in thread