[net-next PATCH v11 5/9] mfd: an8855: Add support for Airoha AN8855 Switch MFD

Christian Marangi
2024-12-09T13:45:48Z

Add support for Airoha AN8855 Switch MFD that provide support for a DSA
switch and a NVMEM provider. Also provide support for a virtual MDIO
passthrough as the PHYs address for the switch are shared with the switch
address

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
---
MAINTAINERS | 1 +
drivers/mfd/Kconfig | 10 +
drivers/mfd/Makefile | 1 +
drivers/mfd/airoha-an8855.c | 278 ++++++++++++++++++++++++++
include/linux/mfd/airoha-an8855-mfd.h | 41 ++++
5 files changed, 331 insertions(+)
create mode 100644 drivers/mfd/airoha-an8855.c
create mode 100644 include/linux/mfd/airoha-an8855-mfd.h

diff --git a/MAINTAINERS b/MAINTAINERS
index f3e3f6938824..7f4d7c48b6e1 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -721,6 +721,7 @@ F: Documentation/devicetree/bindings/mfd/airoha,an8855-mfd.yaml
F: Documentation/devicetree/bindings/net/airoha,an8855-mdio.yaml
F: Documentation/devicetree/bindings/net/dsa/airoha,an8855-switch.yaml
F: Documentation/devicetree/bindings/nvmem/airoha,an8855-efuse.yaml
+F: drivers/mfd/airoha-an8855.c

AIROHA ETHERNET DRIVER
M: Lorenzo Bianconi <lorenzo@kernel.org>
diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index ae23b317a64e..3a0b84991408 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -53,6 +53,16 @@ config MFD_ALTERA_SYSMGR
using regmap_mmio accesses for ARM32 parts and SMC calls to
EL3 for ARM64 parts.

+config MFD_AIROHA_AN8855
+ tristate "Airoha AN8855 Switch MFD"
+ select MFD_CORE
+ select MDIO_DEVICE
+ depends on NETDEVICES && OF
+ help
+ Support for the Airoha AN8855 Switch MFD. This is a SoC Switch
+ that provides various peripherals. Currently it provides a
+ DSA switch and a NVMEM provider.
+
config MFD_ACT8945A
tristate "Active-semi ACT8945A"
select MFD_CORE
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index e057d6d6faef..bcbeb36ab19d 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -8,6 +8,7 @@ obj-$(CONFIG_MFD_88PM860X) += 88pm860x.o
obj-$(CONFIG_MFD_88PM800) += 88pm800.o 88pm80x.o
obj-$(CONFIG_MFD_88PM805) += 88pm805.o 88pm80x.o
obj-$(CONFIG_MFD_88PM886_PMIC) += 88pm886.o
+obj-$(CONFIG_MFD_AIROHA_AN8855) += airoha-an8855.o
obj-$(CONFIG_MFD_ACT8945A) += act8945a.o
obj-$(CONFIG_MFD_SM501) += sm501.o
obj-$(CONFIG_ARCH_BCM2835) += bcm2835-pm.o
diff --git a/drivers/mfd/airoha-an8855.c b/drivers/mfd/airoha-an8855.c
new file mode 100644
index 000000000000..eeaea348aa41
--- /dev/null
+++ b/drivers/mfd/airoha-an8855.c
@@ -0,0 +1,278 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * MFD driver for Airoha AN8855 Switch
+ */
+
+#include <linux/mfd/airoha-an8855-mfd.h>
+#include <linux/mfd/core.h>
+#include <linux/mdio.h>
+#include <linux/module.h>
+#include <linux/phy.h>
+#include <linux/regmap.h>
+
+static const struct mfd_cell an8855_mfd_devs[] = {
+ {
+ .name = "an8855-efuse",
+ .of_compatible = "airoha,an8855-efuse",
+ }, {
+ .name = "an8855-switch",
+ .of_compatible = "airoha,an8855-switch",
+ }, {
+ .name = "an8855-mdio",
+ .of_compatible = "airoha,an8855-mdio",
+ }
+};
+
+int an8855_mii_set_page(struct an8855_mfd_priv *priv, u8 phy_id,
+ u8 page) __must_hold(&priv->bus->mdio_lock)
+{
+ struct mii_bus *bus = priv->bus;
+ int ret;
+
+ ret = __mdiobus_write(bus, phy_id, AN8855_PHY_SELECT_PAGE, page);
+ if (ret < 0)
+ dev_err_ratelimited(&bus->dev,
+ "failed to set an8855 mii page\n");
+
+ /* Cache current page if next mii read/write is for switch */
+ priv->current_page = page;
+ return ret < 0 ? ret : 0;
+}
+EXPORT_SYMBOL_GPL(an8855_mii_set_page);
+
+static int an8855_mii_read32(struct mii_bus *bus, u8 phy_id, u32 reg,
+ u32 *val) __must_hold(&bus->mdio_lock)
+{
+ int lo, hi, ret;
+
+ ret = __mdiobus_write(bus, phy_id, AN8855_PBUS_MODE,
+ AN8855_PBUS_MODE_ADDR_FIXED);
+ if (ret < 0)
+ goto err;
+
+ ret = __mdiobus_write(bus, phy_id, AN8855_PBUS_RD_ADDR_HIGH,
+ upper_16_bits(reg));
+ if (ret < 0)
+ goto err;
+ ret = __mdiobus_write(bus, phy_id, AN8855_PBUS_RD_ADDR_LOW,
+ lower_16_bits(reg));
+ if (ret < 0)
+ goto err;
+
+ hi = __mdiobus_read(bus, phy_id, AN8855_PBUS_RD_DATA_HIGH);
+ if (hi < 0) {
+ ret = hi;
+ goto err;
+ }
+ lo = __mdiobus_read(bus, phy_id, AN8855_PBUS_RD_DATA_LOW);
+ if (lo < 0) {
+ ret = lo;
+ goto err;
+ }
+
+ *val = ((u16)hi << 16) | ((u16)lo & 0xffff);
+
+ return 0;
+err:
+ dev_err_ratelimited(&bus->dev,
+ "failed to read an8855 register\n");
+ return ret;
+}
+
+static int an8855_regmap_read(void *ctx, uint32_t reg, uint32_t *val)
+{
+ struct an8855_mfd_priv *priv = ctx;
+ struct mii_bus *bus = priv->bus;
+ u16 addr = priv->switch_addr;
+ int ret;
+
+ mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
+ ret = an8855_mii_set_page(priv, addr, AN8855_PHY_PAGE_EXTENDED_4);
+ if (ret < 0)
+ goto exit;
+
+ ret = an8855_mii_read32(bus, addr, reg, val);
+
+exit:
+ mutex_unlock(&bus->mdio_lock);
+
+ return ret < 0 ? ret : 0;
+}
+
+static int an8855_mii_write32(struct mii_bus *bus, u8 phy_id, u32 reg,
+ u32 val) __must_hold(&bus->mdio_lock)
+{
+ int ret;
+
+ ret = __mdiobus_write(bus, phy_id, AN8855_PBUS_MODE,
+ AN8855_PBUS_MODE_ADDR_FIXED);
+ if (ret < 0)
+ goto err;
+
+ ret = __mdiobus_write(bus, phy_id, AN8855_PBUS_WR_ADDR_HIGH,
+ upper_16_bits(reg));
+ if (ret < 0)
+ goto err;
+ ret = __mdiobus_write(bus, phy_id, AN8855_PBUS_WR_ADDR_LOW,
+ lower_16_bits(reg));
+ if (ret < 0)
+ goto err;
+
+ ret = __mdiobus_write(bus, phy_id, AN8855_PBUS_WR_DATA_HIGH,
+ upper_16_bits(val));
+ if (ret < 0)
+ goto err;
+ ret = __mdiobus_write(bus, phy_id, AN8855_PBUS_WR_DATA_LOW,
+ lower_16_bits(val));
+ if (ret < 0)
+ goto err;
+
+ return 0;
+err:
+ dev_err_ratelimited(&bus->dev,
+ "failed to write an8855 register\n");
+ return ret;
+}
+
+static int
+an8855_regmap_write(void *ctx, uint32_t reg, uint32_t val)
+{
+ struct an8855_mfd_priv *priv = ctx;
+ struct mii_bus *bus = priv->bus;
+ u16 addr = priv->switch_addr;
+ int ret;
+
+ mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
+ ret = an8855_mii_set_page(priv, addr, AN8855_PHY_PAGE_EXTENDED_4);
+ if (ret < 0)
+ goto exit;
+
+ ret = an8855_mii_write32(bus, addr, reg, val);
+
+exit:
+ mutex_unlock(&bus->mdio_lock);
+
+ return ret < 0 ? ret : 0;
+}
+
+static int an8855_regmap_update_bits(void *ctx, uint32_t reg, uint32_t mask,
+ uint32_t write_val)
+{
+ struct an8855_mfd_priv *priv = ctx;
+ struct mii_bus *bus = priv->bus;
+ u16 addr = priv->switch_addr;
+ u32 val;
+ int ret;
+
+ mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
+ ret = an8855_mii_set_page(priv, addr, AN8855_PHY_PAGE_EXTENDED_4);
+ if (ret < 0)
+ goto exit;
+
+ ret = an8855_mii_read32(bus, addr, reg, &val);
+ if (ret < 0)
+ goto exit;
+
+ val &= ~mask;
+ val |= write_val;
+ ret = an8855_mii_write32(bus, addr, reg, val);
+
+exit:
+ mutex_unlock(&bus->mdio_lock);
+
+ return ret < 0 ? ret : 0;
+}
+
+static const struct regmap_range an8855_readable_ranges[] = {
+ regmap_reg_range(0x10000000, 0x10000fff), /* SCU */
+ regmap_reg_range(0x10001000, 0x10001fff), /* RBUS */
+ regmap_reg_range(0x10002000, 0x10002fff), /* MCU */
+ regmap_reg_range(0x10005000, 0x10005fff), /* SYS SCU */
+ regmap_reg_range(0x10007000, 0x10007fff), /* I2C Slave */
+ regmap_reg_range(0x10008000, 0x10008fff), /* I2C Master */
+ regmap_reg_range(0x10009000, 0x10009fff), /* PDMA */
+ regmap_reg_range(0x1000a100, 0x1000a2ff), /* General Purpose Timer */
+ regmap_reg_range(0x1000a200, 0x1000a2ff), /* GPU timer */
+ regmap_reg_range(0x1000a300, 0x1000a3ff), /* GPIO */
+ regmap_reg_range(0x1000a400, 0x1000a5ff), /* EFUSE */
+ regmap_reg_range(0x1000c000, 0x1000cfff), /* GDMP CSR */
+ regmap_reg_range(0x10010000, 0x1001ffff), /* GDMP SRAM */
+ regmap_reg_range(0x10200000, 0x10203fff), /* Switch - ARL Global */
+ regmap_reg_range(0x10204000, 0x10207fff), /* Switch - BMU */
+ regmap_reg_range(0x10208000, 0x1020bfff), /* Switch - ARL Port */
+ regmap_reg_range(0x1020c000, 0x1020cfff), /* Switch - SCH */
+ regmap_reg_range(0x10210000, 0x10213fff), /* Switch - MAC */
+ regmap_reg_range(0x10214000, 0x10217fff), /* Switch - MIB */
+ regmap_reg_range(0x10218000, 0x1021bfff), /* Switch - Port Control */
+ regmap_reg_range(0x1021c000, 0x1021ffff), /* Switch - TOP */
+ regmap_reg_range(0x10220000, 0x1022ffff), /* SerDes */
+ regmap_reg_range(0x10286000, 0x10286fff), /* RG Batcher */
+ regmap_reg_range(0x1028c000, 0x1028ffff), /* ETHER_SYS */
+ regmap_reg_range(0x30000000, 0x37ffffff), /* I2C EEPROM */
+ regmap_reg_range(0x38000000, 0x3fffffff), /* BOOT_ROM */
+ regmap_reg_range(0xa0000000, 0xbfffffff), /* GPHY */
+};
+
+static const struct regmap_access_table an8855_readable_table = {
+ .yes_ranges = an8855_readable_ranges,
+ .n_yes_ranges = ARRAY_SIZE(an8855_readable_ranges),
+};
+
+static const struct regmap_config an8855_regmap_config = {
+ .reg_bits = 32,
+ .val_bits = 32,
+ .reg_stride = 4,
+ .max_register = 0xbfffffff,
+ .reg_read = an8855_regmap_read,
+ .reg_write = an8855_regmap_write,
+ .reg_update_bits = an8855_regmap_update_bits,
+ .disable_locking = true,
+ .rd_table = &an8855_readable_table,
+};
+
+static int an8855_mfd_probe(struct mdio_device *mdiodev)
+{
+ struct an8855_mfd_priv *priv;
+ struct regmap *regmap;
+
+ priv = devm_kzalloc(&mdiodev->dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->bus = mdiodev->bus;
+ priv->dev = &mdiodev->dev;
+ priv->switch_addr = mdiodev->addr;
+ /* no DMA for mdiobus, mute warning for DMA mask not set */
+ priv->dev->dma_mask = &priv->dev->coherent_dma_mask;
+
+ regmap = devm_regmap_init(priv->dev, NULL, priv,
+ &an8855_regmap_config);
+ if (IS_ERR(regmap))
+ dev_err_probe(priv->dev, PTR_ERR(priv->dev),
+ "regmap initialization failed\n");
+
+ dev_set_drvdata(&mdiodev->dev, priv);
+
+ return devm_mfd_add_devices(priv->dev, PLATFORM_DEVID_AUTO, an8855_mfd_devs,
+ ARRAY_SIZE(an8855_mfd_devs), NULL, 0,
+ NULL);
+}
+
+static const struct of_device_id an8855_mfd_of_match[] = {
+ { .compatible = "airoha,an8855-mfd" },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, an8855_mfd_of_match);
+
+static struct mdio_driver an8855_mfd_driver = {
+ .probe = an8855_mfd_probe,
+ .mdiodrv.driver = {
+ .name = "an8855",
+ .of_match_table = an8855_mfd_of_match,
+ },
+};
+mdio_module_driver(an8855_mfd_driver);
+
+MODULE_AUTHOR("Christian Marangi <ansuelsmth@gmail.com>");
+MODULE_DESCRIPTION("Driver for Airoha AN8855 MFD");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/mfd/airoha-an8855-mfd.h b/include/linux/mfd/airoha-an8855-mfd.h
new file mode 100644
index 000000000000..56061566a079
--- /dev/null
+++ b/include/linux/mfd/airoha-an8855-mfd.h
@@ -0,0 +1,41 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * MFD driver for Airoha AN8855 Switch
+ */
+#ifndef _LINUX_INCLUDE_MFD_AIROHA_AN8855_MFD_H
+#define _LINUX_INCLUDE_MFD_AIROHA_AN8855_MFD_H
+
+#include <linux/bitfield.h>
+
+/* MII Registers */
+#define AN8855_PHY_SELECT_PAGE 0x1f
+#define AN8855_PHY_PAGE GENMASK(2, 0)
+#define AN8855_PHY_PAGE_STANDARD FIELD_PREP_CONST(AN8855_PHY_PAGE, 0x0)
+#define AN8855_PHY_PAGE_EXTENDED_1 FIELD_PREP_CONST(AN8855_PHY_PAGE, 0x1)
+#define AN8855_PHY_PAGE_EXTENDED_4 FIELD_PREP_CONST(AN8855_PHY_PAGE, 0x4)
+
+/* MII Registers Page 4 */
+#define AN8855_PBUS_MODE 0x10
+#define AN8855_PBUS_MODE_ADDR_FIXED 0x0
+#define AN8855_PBUS_MODE_ADDR_INCR BIT(15)
+#define AN8855_PBUS_WR_ADDR_HIGH 0x11
+#define AN8855_PBUS_WR_ADDR_LOW 0x12
+#define AN8855_PBUS_WR_DATA_HIGH 0x13
+#define AN8855_PBUS_WR_DATA_LOW 0x14
+#define AN8855_PBUS_RD_ADDR_HIGH 0x15
+#define AN8855_PBUS_RD_ADDR_LOW 0x16
+#define AN8855_PBUS_RD_DATA_HIGH 0x17
+#define AN8855_PBUS_RD_DATA_LOW 0x18
+
+struct an8855_mfd_priv {
+ struct device *dev;
+ struct mii_bus *bus;
+
+ unsigned int switch_addr;
+ u16 current_page;
+};
+
+int an8855_mii_set_page(struct an8855_mfd_priv *priv, u8 phy_id,
+ u8 page);
+
+#endif
--
2.45.2