diff --git a/MAINTAINERS b/MAINTAINERS
index 75fe8f571210d4c543db0c67ce10bf7c852e881f..043a5c3dcc124d23945a1d15c28745e0991d1ae3 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -20115,6 +20115,13 @@ S: Maintained
T: git https://github.com/pkshih/rtw.git
F: drivers/net/wireless/realtek/rtl8xxxu/
+RTL9300 I2C DRIVER (rtl9300-i2c)
+M: Chris Packham <chris.packham@alliedtelesis.co.nz>
+L: linux-i2c@vger.kernel.org
+S: Maintained
+F: Documentation/devicetree/bindings/i2c/realtek,rtl9301-i2c.yaml
+F: drivers/i2c/busses/i2c-rtl9300.c
+
RTRS TRANSPORT DRIVERS
M: Md. Haris Iqbal <haris.iqbal@ionos.com>
M: Jack Wang <jinpu.wang@ionos.com>
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index db4f9a0c3d9f62769b18851ca4feb3f1cd17b69f..bd9a6bcaaca437accdc24d56003192693868e447 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -1053,6 +1053,16 @@ config I2C_RK3X
This driver can also be built as a module. If so, the module will
be called i2c-rk3x.
+config I2C_RTL9300
+ tristate "Realtek RTL9300 I2C controller"
+ depends on MACH_REALTEK_RTL || COMPILE_TEST
+ help
+ Say Y here to include support for the I2C controller in Realtek
+ RTL9300 SoCs.
+
+ This driver can also be built as a module. If so, the module will
+ be called i2c-rtl9300.
+
config I2C_RZV2M
tristate "Renesas RZ/V2M adapter"
depends on ARCH_RENESAS || COMPILE_TEST
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index 3e345c4779c33c228c1ea1255b30191ca1681463..49154c7bceee5368323d4b4f12e615e67d55eefe 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -100,6 +100,7 @@ obj-$(CONFIG_I2C_QCOM_GENI) += i2c-qcom-geni.o
obj-$(CONFIG_I2C_QUP) += i2c-qup.o
obj-$(CONFIG_I2C_RIIC) += i2c-riic.o
obj-$(CONFIG_I2C_RK3X) += i2c-rk3x.o
+obj-$(CONFIG_I2C_RTL9300) += i2c-rtl9300.o
obj-$(CONFIG_I2C_RZV2M) += i2c-rzv2m.o
obj-$(CONFIG_I2C_S3C2410) += i2c-s3c2410.o
obj-$(CONFIG_I2C_SH7760) += i2c-sh7760.o
diff --git a/drivers/i2c/busses/i2c-rtl9300.c b/drivers/i2c/busses/i2c-rtl9300.c
new file mode 100644
index 0000000000000000000000000000000000000000..e064e8a4a1f0824abc82fa677866b85f99fbe4a7
--- /dev/null
+++ b/drivers/i2c/busses/i2c-rtl9300.c
@@ -0,0 +1,423 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/bits.h>
+#include <linux/i2c.h>
+#include <linux/i2c-mux.h>
+#include <linux/mod_devicetable.h>
+#include <linux/mfd/syscon.h>
+#include <linux/mutex.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+enum rtl9300_bus_freq {
+ RTL9300_I2C_STD_FREQ,
+ RTL9300_I2C_FAST_FREQ,
+};
+
+struct rtl9300_i2c;
+
+struct rtl9300_i2c_chan {
+ struct i2c_adapter adap;
+ struct rtl9300_i2c *i2c;
+ enum rtl9300_bus_freq bus_freq;
+ u8 sda_pin;
+};
+
+#define RTL9300_I2C_MUX_NCHAN 8
+
+struct rtl9300_i2c {
+ struct regmap *regmap;
+ struct device *dev;
+ struct rtl9300_i2c_chan chans[RTL9300_I2C_MUX_NCHAN];
+ u32 reg_base;
+ u8 sda_pin;
+ struct mutex lock;
+};
+
+#define RTL9300_I2C_MST_CTRL1 0x0
+#define RTL9300_I2C_MST_CTRL1_MEM_ADDR_OFS 8
+#define RTL9300_I2C_MST_CTRL1_MEM_ADDR_MASK GENMASK(31, 8)
+#define RTL9300_I2C_MST_CTRL1_SDA_OUT_SEL_OFS 4
+#define RTL9300_I2C_MST_CTRL1_SDA_OUT_SEL_MASK GENMASK(6, 4)
+#define RTL9300_I2C_MST_CTRL1_GPIO_SCL_SEL BIT(3)
+#define RTL9300_I2C_MST_CTRL1_RWOP BIT(2)
+#define RTL9300_I2C_MST_CTRL1_I2C_FAIL BIT(1)
+#define RTL9300_I2C_MST_CTRL1_I2C_TRIG BIT(0)
+#define RTL9300_I2C_MST_CTRL2 0x4
+#define RTL9300_I2C_MST_CTRL2_RD_MODE BIT(15)
+#define RTL9300_I2C_MST_CTRL2_DEV_ADDR_OFS 8
+#define RTL9300_I2C_MST_CTRL2_DEV_ADDR_MASK GENMASK(14, 8)
+#define RTL9300_I2C_MST_CTRL2_DATA_WIDTH_OFS 4
+#define RTL9300_I2C_MST_CTRL2_DATA_WIDTH_MASK GENMASK(7, 4)
+#define RTL9300_I2C_MST_CTRL2_MEM_ADDR_WIDTH_OFS 2
+#define RTL9300_I2C_MST_CTRL2_MEM_ADDR_WIDTH_MASK GENMASK(3, 2)
+#define RTL9300_I2C_MST_CTRL2_SCL_FREQ_OFS 0
+#define RTL9300_I2C_MST_CTRL2_SCL_FREQ_MASK GENMASK(1, 0)
+#define RTL9300_I2C_MST_DATA_WORD0 0x8
+#define RTL9300_I2C_MST_DATA_WORD1 0xc
+#define RTL9300_I2C_MST_DATA_WORD2 0x10
+#define RTL9300_I2C_MST_DATA_WORD3 0x14
+
+#define RTL9300_I2C_MST_GLB_CTRL 0x384
+
+static int rtl9300_i2c_reg_addr_set(struct rtl9300_i2c *i2c, u32 reg, u16 len)
+{
+ u32 val, mask;
+ int ret;
+
+ val = len << RTL9300_I2C_MST_CTRL2_MEM_ADDR_WIDTH_OFS;
+ mask = RTL9300_I2C_MST_CTRL2_MEM_ADDR_WIDTH_MASK;
+
+ ret = regmap_update_bits(i2c->regmap, i2c->reg_base + RTL9300_I2C_MST_CTRL2, mask, val);
+ if (ret)
+ return ret;
+
+ val = reg << RTL9300_I2C_MST_CTRL1_MEM_ADDR_OFS;
+ mask = RTL9300_I2C_MST_CTRL1_MEM_ADDR_MASK;
+
+ return regmap_update_bits(i2c->regmap, i2c->reg_base + RTL9300_I2C_MST_CTRL1, mask, val);
+}
+
+static int rtl9300_i2c_config_io(struct rtl9300_i2c *i2c, u8 sda_pin)
+{
+ int ret;
+ u32 val, mask;
+
+ ret = regmap_update_bits(i2c->regmap, RTL9300_I2C_MST_GLB_CTRL, BIT(sda_pin), BIT(sda_pin));
+ if (ret)
+ return ret;
+
+ val = (sda_pin << RTL9300_I2C_MST_CTRL1_SDA_OUT_SEL_OFS) |
+ RTL9300_I2C_MST_CTRL1_GPIO_SCL_SEL;
+ mask = RTL9300_I2C_MST_CTRL1_SDA_OUT_SEL_MASK | RTL9300_I2C_MST_CTRL1_GPIO_SCL_SEL;
+
+ return regmap_update_bits(i2c->regmap, i2c->reg_base + RTL9300_I2C_MST_CTRL1, mask, val);
+}
+
+static int rtl9300_i2c_config_xfer(struct rtl9300_i2c *i2c, struct rtl9300_i2c_chan *chan,
+ u16 addr, u16 len)
+{
+ u32 val, mask;
+
+ val = chan->bus_freq << RTL9300_I2C_MST_CTRL2_SCL_FREQ_OFS;
+ mask = RTL9300_I2C_MST_CTRL2_SCL_FREQ_MASK;
+
+ val |= addr << RTL9300_I2C_MST_CTRL2_DEV_ADDR_OFS;
+ mask |= RTL9300_I2C_MST_CTRL2_DEV_ADDR_MASK;
+
+ val |= ((len - 1) & 0xf) << RTL9300_I2C_MST_CTRL2_DATA_WIDTH_OFS;
+ mask |= RTL9300_I2C_MST_CTRL2_DATA_WIDTH_MASK;
+
+ mask |= RTL9300_I2C_MST_CTRL2_RD_MODE;
+
+ return regmap_update_bits(i2c->regmap, i2c->reg_base + RTL9300_I2C_MST_CTRL2, mask, val);
+}
+
+static int rtl9300_i2c_read(struct rtl9300_i2c *i2c, u8 *buf, int len)
+{
+ u32 vals[4] = {};
+ int i, ret;
+
+ if (len > 16)
+ return -EIO;
+
+ ret = regmap_bulk_read(i2c->regmap, i2c->reg_base + RTL9300_I2C_MST_DATA_WORD0,
+ vals, ARRAY_SIZE(vals));
+ if (ret)
+ return ret;
+
+ for (i = 0; i < len; i++) {
+ buf[i] = vals[i/4] & 0xff;
+ vals[i/4] >>= 8;
+ }
+
+ return 0;
+}
+
+static int rtl9300_i2c_write(struct rtl9300_i2c *i2c, u8 *buf, int len)
+{
+ u32 vals[4] = {};
+ int i;
+
+ if (len > 16)
+ return -EIO;
+
+ for (i = 0; i < len; i++) {
+ if (i % 4 == 0)
+ vals[i/4] = 0;
+ vals[i/4] <<= 8;
+ vals[i/4] |= buf[i];
+ }
+
+ return regmap_bulk_write(i2c->regmap, i2c->reg_base + RTL9300_I2C_MST_DATA_WORD0,
+ vals, ARRAY_SIZE(vals));
+}
+
+static int rtl9300_i2c_writel(struct rtl9300_i2c *i2c, u32 data)
+{
+ return regmap_write(i2c->regmap, i2c->reg_base + RTL9300_I2C_MST_DATA_WORD0, data);
+}
+
+static int rtl9300_i2c_execute_xfer(struct rtl9300_i2c *i2c, char read_write,
+ int size, union i2c_smbus_data *data, int len)
+{
+ u32 val, mask;
+ int ret;
+
+ val = read_write == I2C_SMBUS_WRITE ? RTL9300_I2C_MST_CTRL1_RWOP : 0;
+ mask = RTL9300_I2C_MST_CTRL1_RWOP;
+
+ val |= RTL9300_I2C_MST_CTRL1_I2C_TRIG;
+ mask |= RTL9300_I2C_MST_CTRL1_I2C_TRIG;
+
+ ret = regmap_update_bits(i2c->regmap, i2c->reg_base + RTL9300_I2C_MST_CTRL1, mask, val);
+ if (ret)
+ return ret;
+
+ ret = regmap_read_poll_timeout(i2c->regmap, i2c->reg_base + RTL9300_I2C_MST_CTRL1,
+ val, !(val & RTL9300_I2C_MST_CTRL1_I2C_TRIG), 100, 2000);
+ if (ret)
+ return ret;
+
+ if (val & RTL9300_I2C_MST_CTRL1_I2C_FAIL)
+ return -EIO;
+
+ if (read_write == I2C_SMBUS_READ) {
+ if (size == I2C_SMBUS_BYTE || size == I2C_SMBUS_BYTE_DATA) {
+ ret = regmap_read(i2c->regmap,
+ i2c->reg_base + RTL9300_I2C_MST_DATA_WORD0, &val);
+ if (ret)
+ return ret;
+ data->byte = val & 0xff;
+ } else if (size == I2C_SMBUS_WORD_DATA) {
+ ret = regmap_read(i2c->regmap,
+ i2c->reg_base + RTL9300_I2C_MST_DATA_WORD0, &val);
+ if (ret)
+ return ret;
+ data->word = val & 0xffff;
+ } else {
+ ret = rtl9300_i2c_read(i2c, &data->block[0], len);
+ if (ret)
+ return ret;
+ }
+ }
+
+ return 0;
+}
+
+static int rtl9300_i2c_smbus_xfer(struct i2c_adapter *adap, u16 addr, unsigned short flags,
+ char read_write, u8 command, int size,
+ union i2c_smbus_data *data)
+{
+ struct rtl9300_i2c_chan *chan = i2c_get_adapdata(adap);
+ struct rtl9300_i2c *i2c = chan->i2c;
+ int len = 0, ret;
+
+ mutex_lock(&i2c->lock);
+ if (chan->sda_pin != i2c->sda_pin) {
+ ret = rtl9300_i2c_config_io(i2c, chan->sda_pin);
+ if (ret)
+ goto out_unlock;
+ i2c->sda_pin = chan->sda_pin;
+ }
+
+ switch (size) {
+ case I2C_SMBUS_QUICK:
+ ret = rtl9300_i2c_config_xfer(i2c, chan, addr, 0);
+ if (ret)
+ goto out_unlock;
+ ret = rtl9300_i2c_reg_addr_set(i2c, 0, 0);
+ if (ret)
+ goto out_unlock;
+ break;
+
+ case I2C_SMBUS_BYTE:
+ if (read_write == I2C_SMBUS_WRITE) {
+ ret = rtl9300_i2c_config_xfer(i2c, chan, addr, 0);
+ if (ret)
+ goto out_unlock;
+ ret = rtl9300_i2c_reg_addr_set(i2c, command, 1);
+ if (ret)
+ goto out_unlock;
+ } else {
+ ret = rtl9300_i2c_config_xfer(i2c, chan, addr, 1);
+ if (ret)
+ goto out_unlock;
+ ret = rtl9300_i2c_reg_addr_set(i2c, 0, 0);
+ if (ret)
+ goto out_unlock;
+ }
+ break;
+
+ case I2C_SMBUS_BYTE_DATA:
+ ret = rtl9300_i2c_reg_addr_set(i2c, command, 1);
+ if (ret)
+ goto out_unlock;
+ ret = rtl9300_i2c_config_xfer(i2c, chan, addr, 1);
+ if (ret)
+ goto out_unlock;
+ if (read_write == I2C_SMBUS_WRITE) {
+ ret = rtl9300_i2c_writel(i2c, data->byte);
+ if (ret)
+ goto out_unlock;
+ }
+ break;
+
+ case I2C_SMBUS_WORD_DATA:
+ ret = rtl9300_i2c_reg_addr_set(i2c, command, 1);
+ if (ret)
+ goto out_unlock;
+ ret = rtl9300_i2c_config_xfer(i2c, chan, addr, 2);
+ if (ret)
+ goto out_unlock;
+ if (read_write == I2C_SMBUS_WRITE) {
+ ret = rtl9300_i2c_writel(i2c, data->word);
+ if (ret)
+ goto out_unlock;
+ }
+ break;
+
+ case I2C_SMBUS_BLOCK_DATA:
+ ret = rtl9300_i2c_reg_addr_set(i2c, command, 1);
+ if (ret)
+ goto out_unlock;
+ ret = rtl9300_i2c_config_xfer(i2c, chan, addr, data->block[0]);
+ if (ret)
+ goto out_unlock;
+ if (read_write == I2C_SMBUS_WRITE) {
+ ret = rtl9300_i2c_write(i2c, &data->block[1], data->block[0]);
+ if (ret)
+ goto out_unlock;
+ }
+ len = data->block[0];
+ break;
+
+ default:
+ dev_err(&adap->dev, "Unsupported transaction %d\n", size);
+ ret = -EOPNOTSUPP;
+ goto out_unlock;
+ }
+
+ ret = rtl9300_i2c_execute_xfer(i2c, read_write, size, data, len);
+
+out_unlock:
+ mutex_unlock(&i2c->lock);
+
+ return ret;
+}
+
+static u32 rtl9300_i2c_func(struct i2c_adapter *a)
+{
+ return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
+ I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
+ I2C_FUNC_SMBUS_BLOCK_DATA;
+}
+
+static const struct i2c_algorithm rtl9300_i2c_algo = {
+ .smbus_xfer = rtl9300_i2c_smbus_xfer,
+ .functionality = rtl9300_i2c_func,
+};
+
+static struct i2c_adapter_quirks rtl9300_i2c_quirks = {
+ .flags = I2C_AQ_NO_CLK_STRETCH,
+ .max_read_len = 16,
+ .max_write_len = 16,
+};
+
+static int rtl9300_i2c_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct rtl9300_i2c *i2c;
+ u32 clock_freq, sda_pin;
+ int ret, i = 0;
+ struct fwnode_handle *child;
+
+ i2c = devm_kzalloc(dev, sizeof(*i2c), GFP_KERNEL);
+ if (!i2c)
+ return -ENOMEM;
+
+ i2c->regmap = syscon_node_to_regmap(dev->parent->of_node);
+ if (IS_ERR(i2c->regmap))
+ return PTR_ERR(i2c->regmap);
+ i2c->dev = dev;
+
+ mutex_init(&i2c->lock);
+
+ ret = device_property_read_u32(dev, "reg", &i2c->reg_base);
+ if (ret)
+ return ret;
+
+ platform_set_drvdata(pdev, i2c);
+
+ if (device_get_child_node_count(dev) >= RTL9300_I2C_MUX_NCHAN)
+ return dev_err_probe(dev, -EINVAL, "Too many channels\n");
+
+ device_for_each_child_node(dev, child) {
+ struct rtl9300_i2c_chan *chan = &i2c->chans[i];
+ struct i2c_adapter *adap = &chan->adap;
+
+ ret = fwnode_property_read_u32(child, "reg", &sda_pin);
+ if (ret)
+ return ret;
+
+ ret = fwnode_property_read_u32(child, "clock-frequency", &clock_freq);
+ if (ret)
+ clock_freq = I2C_MAX_STANDARD_MODE_FREQ;
+
+ switch (clock_freq) {
+ case I2C_MAX_STANDARD_MODE_FREQ:
+ chan->bus_freq = RTL9300_I2C_STD_FREQ;
+ break;
+
+ case I2C_MAX_FAST_MODE_FREQ:
+ chan->bus_freq = RTL9300_I2C_FAST_FREQ;
+ break;
+ default:
+ dev_warn(i2c->dev, "SDA%d clock-frequency %d not supported using default\n",
+ sda_pin, clock_freq);
+ break;
+ }
+
+ chan->sda_pin = sda_pin;
+ chan->i2c = i2c;
+ adap = &i2c->chans[i].adap;
+ adap->owner = THIS_MODULE;
+ adap->algo = &rtl9300_i2c_algo;
+ adap->quirks = &rtl9300_i2c_quirks;
+ adap->retries = 3;
+ adap->dev.parent = dev;
+ i2c_set_adapdata(adap, chan);
+ adap->dev.of_node = to_of_node(child);
+ snprintf(adap->name, sizeof(adap->name), "%s SDA%d\n", dev_name(dev), sda_pin);
+ i++;
+
+ ret = devm_i2c_add_adapter(dev, adap);
+ if (ret)
+ return ret;
+ }
+ i2c->sda_pin = 0xff;
+
+ return 0;
+}
+
+static const struct of_device_id i2c_rtl9300_dt_ids[] = {
+ { .compatible = "realtek,rtl9301-i2c" },
+ { .compatible = "realtek,rtl9302b-i2c" },
+ { .compatible = "realtek,rtl9302c-i2c" },
+ { .compatible = "realtek,rtl9303-i2c" },
+ {}
+};
+MODULE_DEVICE_TABLE(of, i2c_rtl9300_dt_ids);
+
+static struct platform_driver rtl9300_i2c_driver = {
+ .probe = rtl9300_i2c_probe,
+ .driver = {
+ .name = "i2c-rtl9300",
+ .of_match_table = i2c_rtl9300_dt_ids,
+ },
+};
+
+module_platform_driver(rtl9300_i2c_driver);
+
+MODULE_DESCRIPTION("RTL9300 I2C controller driver");
+MODULE_LICENSE("GPL");