In this mode the switch device and the internal phys will be managed via
I2C interface.
Signed-off-by: Sergio Paracuellos <sergio.paracuellos@xxxxxxxxx>
---
Changes v3:
- return -EINVAL if 'ksz_i2c_write' is called with len 0 to
avoid a possible memory corruption.
Changes v2:
- Use dev->txbuf as transmition buffer which is allocated using
kernel allocators avoiding some possible DMA issues using the
stack.
drivers/net/dsa/microchip/Kconfig | 6 +
drivers/net/dsa/microchip/Makefile | 1 +
drivers/net/dsa/microchip/ksz9477_i2c.c | 272 ++++++++++++++++++++++++
3 files changed, 279 insertions(+)
create mode 100644 drivers/net/dsa/microchip/ksz9477_i2c.c
diff --git a/drivers/net/dsa/microchip/Kconfig b/drivers/net/dsa/microchip/Kconfig
index a8caf9249d50..162fec43d204 100644
--- a/drivers/net/dsa/microchip/Kconfig
+++ b/drivers/net/dsa/microchip/Kconfig
@@ -14,3 +14,9 @@ config NET_DSA_MICROCHIP_KSZ9477_SPI
depends on NET_DSA_MICROCHIP_KSZ9477 && SPI
help
Select to enable support for registering switches configured through SPI.
+
+config NET_DSA_MICROCHIP_KSZ9477_I2C
+ tristate "KSZ series I2C connected switch driver"
+ depends on NET_DSA_MICROCHIP_KSZ9477 && I2C
+ help
+ Select to enable support for registering switches configured through I2C.
diff --git a/drivers/net/dsa/microchip/Makefile b/drivers/net/dsa/microchip/Makefile
index 3142c18b8f57..eb9b768face2 100644
--- a/drivers/net/dsa/microchip/Makefile
+++ b/drivers/net/dsa/microchip/Makefile
@@ -1,3 +1,4 @@
obj-$(CONFIG_NET_DSA_MICROCHIP_KSZ_COMMON) += ksz_common.o
obj-$(CONFIG_NET_DSA_MICROCHIP_KSZ9477) += ksz9477.o
obj-$(CONFIG_NET_DSA_MICROCHIP_KSZ9477_SPI) += ksz9477_spi.o
+obj-$(CONFIG_NET_DSA_MICROCHIP_KSZ9477_I2C) += ksz9477_i2c.o
diff --git a/drivers/net/dsa/microchip/ksz9477_i2c.c b/drivers/net/dsa/microchip/ksz9477_i2c.c
new file mode 100644
index 000000000000..52f63c0d35e7
--- /dev/null
+++ b/drivers/net/dsa/microchip/ksz9477_i2c.c
@@ -0,0 +1,272 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Microchip KSZ series register access through I2C
+ *
+ * Author: Sergio Paracuellos <sergio.paracuellos@xxxxxxxxx>
+ */
+
+#include <linux/i2c.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+
+#include "ksz_priv.h"
+
+/* Enough to read all switch port registers. */
+#define I2C_TX_BUF_LEN 0x100
+
+/**
+ * ksz_i2c_read_reg - issue read register command
+ * @client: i2c client structure
+ * @reg: The register address.
+ * @val: The buffer to return the result into.
+ * @len: The length of data expected.
+ *
+ * This is the low level read call that issues the necessary i2c message(s)
+ * to read data from the register specified in @reg.
+ */
+static int ksz_i2c_read_reg(struct i2c_client *client, u32 reg, u8 *val,
+ unsigned int len)
+{
+ struct i2c_adapter *adapter = client->adapter;
+ struct i2c_msg msg[2];
+ int ret;
+
+ msg[0].addr = client->addr;
+ msg[0].flags = 0;
+ msg[0].len = 2;
+ msg[0].buf = val;
+
+ msg[1].addr = client->addr;
+ msg[1].flags = I2C_M_RD;
+ msg[1].len = len;
+ msg[1].buf = val;
+
+ ret = i2c_transfer(adapter, msg, 2);
+ return (ret != 2) ? -EREMOTEIO : 0;
+}
+
+static int ksz_i2c_read(struct ksz_device *dev, u32 reg, u8 *data,
+ unsigned int len)
+{
+ struct i2c_client *client = dev->priv;
+ int ret;
+
+ len = (len > I2C_TX_BUF_LEN) ? I2C_TX_BUF_LEN : len;
+ dev->txbuf[0] = (u8)(reg >> 8);
+ dev->txbuf[1] = (u8)reg;
+
+ ret = ksz_i2c_read_reg(client, reg, dev->txbuf, len);
+ if (!ret)
+ memcpy(data, dev->txbuf, len);
+
+ return ret;
+}
+
+static int ksz_i2c_read8(struct ksz_device *dev, u32 reg, u8 *val)
+{
+ return ksz_i2c_read(dev, reg, val, 1);
+}
+
+static int ksz_i2c_read16(struct ksz_device *dev, u32 reg, u16 *val)
+{
+ int ret = ksz_i2c_read(dev, reg, (u8 *)val, 2);
+
+ if (!ret)
+ *val = be16_to_cpu(*val);
+
+ return ret;
+}
+
+static int ksz_i2c_read24(struct ksz_device *dev, u32 reg, u32 *val)
+{
+ int ret;
+
+ *val = 0;
+ ret = ksz_i2c_read(dev, reg, (u8 *)val, 3);
+
+ if (!ret) {
+ *val = be32_to_cpu(*val);
+ /* convert to 24 bit */
+ *val >>= 8;
+ }
+
+ return ret;
+}
+
+static int ksz_i2c_read32(struct ksz_device *dev, u32 reg, u32 *val)
+{
+ int ret = ksz_i2c_read(dev, reg, (u8 *)val, 4);
+
+ if (!ret)
+ *val = be32_to_cpu(*val);
+
+ return ret;
+}
+
+/**
+ * ksz_i2c_write_reg - issue write register command
+ * @client: i2c client structure
+ * @reg: The register address.
+ * @val: value to write
+ * @len: The length of data
+ *
+ * This is the low level write call that issues the necessary i2c message(s)
+ * to write data to the register specified in @reg.
+ */
+static int ksz_i2c_write_reg(struct i2c_client *client, u32 reg, u8 *val,
+ unsigned int len)
+{
+ struct i2c_adapter *adapter = client->adapter;
+ struct i2c_msg msg;
+ int ret;
+
+ msg.addr = client->addr;
+ msg.flags = 0;
+ msg.len = 2 + len;
+ msg.buf = val;
+
+ ret = i2c_transfer(adapter, &msg, 1);
+ return (ret != 1) ? -EREMOTEIO : 0;
+}
+
+static int ksz_i2c_write(struct ksz_device *dev, u32 reg, u8 *val,
+ unsigned int len)
+{
+ struct i2c_client *client = dev->priv;
+ unsigned int cnt = len;
+ int i;
+
+ if (len == 0)
+ return -EINVAL;
+
+ len = (len > I2C_TX_BUF_LEN) ? I2C_TX_BUF_LEN : len;
+ dev->txbuf[0] = (u8)(reg >> 8);
+ dev->txbuf[1] = (u8)reg;
+ i = 2;
+
+ do {
+ dev->txbuf[i++] = (u8)(*val >> (8 * (cnt - 1)));
+ cnt--;
+ } while (cnt);
+
+ return ksz_i2c_write_reg(client, reg, dev->txbuf, len);
+}
+
+static int ksz_i2c_write8(struct ksz_device *dev, u32 reg, u8 value)
+{
+ return ksz_i2c_write(dev, reg, &value, 1);
+}
+
+static int ksz_i2c_write16(struct ksz_device *dev, u32 reg, u16 value)
+{
+ value = cpu_to_be16(value);
+ return ksz_i2c_write(dev, reg, (u8 *)&value, 2);
+}
+
+static int ksz_i2c_write24(struct ksz_device *dev, u32 reg, u32 value)
+{
+ /* make it to big endian 24bit from MSB */
+ value <<= 8;
+ value = cpu_to_be32(value);
+
+ return ksz_i2c_write(dev, reg, (u8 *)&value, 3);
+}
+
+static int ksz_i2c_write32(struct ksz_device *dev, u32 reg, u32 value)
+{
+ value = cpu_to_be32(value);
+ return ksz_i2c_write(dev, reg, (u8 *)&value, 4);
+}
+
+static int ksz_i2c_get(struct ksz_device *dev, u32 reg, void *data, size_t len)
+{
+ return ksz_i2c_read(dev, reg, data, len);
+}
+
+static int ksz_i2c_set(struct ksz_device *dev, u32 reg, void *data, size_t len)
+{
+ return ksz_i2c_write(dev, reg, data, len);
+}
+
+static const struct ksz_io_ops ksz_i2c_ops = {
+ .read8 = ksz_i2c_read8,
+ .read16 = ksz_i2c_read16,
+ .read24 = ksz_i2c_read24,
+ .read32 = ksz_i2c_read32,
+ .write8 = ksz_i2c_write8,
+ .write16 = ksz_i2c_write16,
+ .write24 = ksz_i2c_write24,
+ .write32 = ksz_i2c_write32,
+ .get = ksz_i2c_get,
+ .set = ksz_i2c_set,
+};
+
+static int ksz_i2c_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct ksz_device *dev;
+ int ret;
+
+ dev = ksz_switch_alloc(&client->dev, &ksz_i2c_ops, client);
+ if (!dev)
+ return -ENOMEM;
+
+ if (client->dev.platform_data)
+ dev->pdata = client->dev.platform_data;
+
+ dev->txbuf = devm_kzalloc(dev->dev, 2 + I2C_TX_BUF_LEN, GFP_KERNEL);
+ if (!dev->txbuf)
+ return -ENOMEM;
+
+ i2c_set_clientdata(client, dev);
+
+ ret = ksz9477_switch_register(dev);
+ if (ret) {
+ dev_err(&client->dev, "registering switch (ret: %d)\n", ret);
+ return ret;
+ }
+
+ return 0;
+}
+
+static int ksz_i2c_remove(struct i2c_client *client)
+{
+ struct ksz_device *dev = i2c_get_clientdata(client);
+
+ if (dev)
+ ksz_switch_remove(dev);
+
+ return 0;
+}
+
+static const struct i2c_device_id ksz_i2c_id[] = {
+ { "ksz9477-switch", 0 },
+ {},
+};
+
+MODULE_DEVICE_TABLE(i2c, ksz_i2c_id);
+
+static const struct of_device_id ksz_dt_match[] = {
+ { .compatible = "microchip,ksz9477" },
+ { .compatible = "microchip,ksz9897" },
+ {},
+};
+
+MODULE_DEVICE_TABLE(of, ksz_dt_match);
+
+static struct i2c_driver ksz_i2c_driver = {
+ .driver = {
+ .name = "ksz9477-switch",
+ .owner = THIS_MODULE,
+ .of_match_table = ksz_dt_match,
+ },
+ .probe = ksz_i2c_probe,
+ .remove = ksz_i2c_remove,
+ .id_table = ksz_i2c_id,
+};
+
+module_i2c_driver(ksz_i2c_driver);
+
+MODULE_AUTHOR("Sergio Paracuellos <sergio.paracuellos@xxxxxxxxx>");
+MODULE_DESCRIPTION("Microchip KSZ Series Switch I2C access Driver");
+MODULE_LICENSE("GPL");
--
2.19.1
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