]> git.ipfire.org Git - thirdparty/kernel/linux.git/commitdiff
i2c: Add driver for the RTL9300 I2C controller
authorChris Packham <chris.packham@alliedtelesis.co.nz>
Wed, 6 Nov 2024 00:18:35 +0000 (13:18 +1300)
committerAndi Shyti <andi.shyti@kernel.org>
Sun, 17 Nov 2024 10:58:57 +0000 (11:58 +0100)
Add support for the I2C controller on the RTL9300 SoC. There are two I2C
controllers in the RTL9300 that are part of the Ethernet switch register
block. Each of these controllers owns a SCL pin (GPIO8 for the fiorst
I2C controller, GPIO17 for the second). There are 8 possible SDA pins
(GPIO9-16) that can be assigned to either I2C controller. This
relationship is represented in the device tree with a child node for
each SDA line in use.

This is based on the openwrt implementation[1] but has been
significantly modified

[1] - https://git.openwrt.org/?p=openwrt/openwrt.git;a=blob;f=target/linux/realtek/files-5.15/drivers/i2c/busses/i2c-rtl9300.c

Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Reviewed-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
MAINTAINERS
drivers/i2c/busses/Kconfig
drivers/i2c/busses/Makefile
drivers/i2c/busses/i2c-rtl9300.c [new file with mode: 0644]

index 75fe8f571210d4c543db0c67ce10bf7c852e881f..043a5c3dcc124d23945a1d15c28745e0991d1ae3 100644 (file)
@@ -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>
index db4f9a0c3d9f62769b18851ca4feb3f1cd17b69f..bd9a6bcaaca437accdc24d56003192693868e447 100644 (file)
@@ -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
index 3e345c4779c33c228c1ea1255b30191ca1681463..49154c7bceee5368323d4b4f12e615e67d55eefe 100644 (file)
@@ -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 (file)
index 0000000..e064e8a
--- /dev/null
@@ -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");