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https://github.com/openwrt/openwrt.git
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f4bdb7fdcc
The RTL9300/RTL9310 I2C controllers have support for 2 independent I2C masters, each with a fixed SCL pin, that cannot be changed. Each of these masters can use 8 (RTL9300) or 16 (RTL9310) different pins for SDA. This multiplexer directly controls the two masters and their shared IO configuration registers to allow multiplexing between any of these busses. The two masters cannot be used in parallel as the multiplex is protected by a standard multiplex lock. Signed-off-by: Birger Koblitz <git@birger-koblitz.de>
489 lines
13 KiB
C
489 lines
13 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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#include <linux/module.h>
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#include <linux/of_platform.h>
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#include "i2c-rtl9300.h"
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#define REG(i, x) (i->base + x + (i->scl_num ? i->mst2_offset : 0))
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#define REG_MASK(i, clear, set, reg) \
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writel((readl(REG(i, reg)) & ~(clear)) | (set), REG(i, reg))
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struct i2c_drv_data {
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int scl0_pin;
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int scl1_pin;
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int sda0_pin;
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struct i2c_algorithm *algo;
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int (*read)(struct rtl9300_i2c *i2c, u8 *buf, int len);
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int (*write)(struct rtl9300_i2c *i2c, u8 *buf, int len);
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void (*reg_addr_set)(struct rtl9300_i2c *i2c, u32 reg, u16 len);
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int (*config_xfer)(struct rtl9300_i2c *i2c, u16 addr, u16 len);
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int (*execute_xfer)(struct rtl9300_i2c *i2c, char read_write, int size,
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union i2c_smbus_data * data, int len);
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void (*writel)(struct rtl9300_i2c *i2c, u32 data);
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void (*config_io)(struct rtl9300_i2c *i2c, int scl_num, int sda_num);
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u32 mst2_offset;
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};
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DEFINE_MUTEX(i2c_lock);
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static void rtl9300_i2c_reg_addr_set(struct rtl9300_i2c *i2c, u32 reg, u16 len)
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{
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// Set register address width
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REG_MASK(i2c, 0x3 << RTL9300_I2C_CTRL2_MADDR_WIDTH, len << RTL9300_I2C_CTRL2_MADDR_WIDTH,
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RTL9300_I2C_CTRL2);
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// Set register address
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REG_MASK(i2c, 0xffffff << RTL9300_I2C_CTRL1_MEM_ADDR, reg << RTL9300_I2C_CTRL1_MEM_ADDR,
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RTL9300_I2C_CTRL1);
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}
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static void rtl9310_i2c_reg_addr_set(struct rtl9300_i2c *i2c, u32 reg, u16 len)
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{
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// Set register address width
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REG_MASK(i2c, 0x3 << RTL9310_I2C_CTRL_MADDR_WIDTH, len << RTL9310_I2C_CTRL_MADDR_WIDTH,
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RTL9310_I2C_CTRL);
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// Set register address
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writel(reg, REG(i2c, RTL9310_I2C_MEMADDR));
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}
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static void rtl9300_i2c_config_io(struct rtl9300_i2c *i2c, int scl_num, int sda_num)
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{
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u32 v;
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// Set SCL pin
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REG_MASK(i2c, 0, BIT(RTL9300_I2C_CTRL1_GPIO8_SCL_SEL), RTL9300_I2C_CTRL1);
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// Set SDA pin
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REG_MASK(i2c, 0x7 << RTL9300_I2C_CTRL1_SDA_OUT_SEL,
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i2c->sda_num << RTL9300_I2C_CTRL1_SDA_OUT_SEL, RTL9300_I2C_CTRL1);
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// Set SDA pin to I2C functionality
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v = readl(i2c->base + RTL9300_I2C_MST_GLB_CTRL);
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v |= BIT(i2c->sda_num);
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writel(v, i2c->base + RTL9300_I2C_MST_GLB_CTRL);
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}
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static void rtl9310_i2c_config_io(struct rtl9300_i2c *i2c, int scl_num, int sda_num)
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{
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u32 v;
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// Set SCL pin
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REG_MASK(i2c, 0, BIT(RTL9310_I2C_MST_IF_SEL_GPIO_SCL_SEL + scl_num), RTL9310_I2C_MST_IF_SEL);
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// Set SDA pin
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REG_MASK(i2c, 0x7 << RTL9310_I2C_CTRL_SDA_OUT_SEL,
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i2c->sda_num << RTL9310_I2C_CTRL_SDA_OUT_SEL, RTL9310_I2C_CTRL);
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// Set SDA pin to I2C functionality
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v = readl(i2c->base + RTL9310_I2C_MST_IF_SEL);
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v |= BIT(i2c->sda_num);
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writel(v, i2c->base + RTL9310_I2C_MST_IF_SEL);
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}
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static int rtl9300_i2c_config_xfer(struct rtl9300_i2c *i2c, u16 addr, u16 len)
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{
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// Set bus frequency
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REG_MASK(i2c, 0x3 << RTL9300_I2C_CTRL2_SCL_FREQ,
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i2c->bus_freq << RTL9300_I2C_CTRL2_SCL_FREQ, RTL9300_I2C_CTRL2);
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// Set slave device address
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REG_MASK(i2c, 0x7f << RTL9300_I2C_CTRL2_DEV_ADDR,
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addr << RTL9300_I2C_CTRL2_DEV_ADDR, RTL9300_I2C_CTRL2);
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// Set data length
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REG_MASK(i2c, 0xf << RTL9300_I2C_CTRL2_DATA_WIDTH,
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((len - 1) & 0xf) << RTL9300_I2C_CTRL2_DATA_WIDTH, RTL9300_I2C_CTRL2);
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// Set read mode to random
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REG_MASK(i2c, 0x1 << RTL9300_I2C_CTRL2_READ_MODE, 0, RTL9300_I2C_CTRL2);
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return 0;
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}
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static int rtl9310_i2c_config_xfer(struct rtl9300_i2c *i2c, u16 addr, u16 len)
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{
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// Set bus frequency
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REG_MASK(i2c, 0x3 << RTL9310_I2C_CTRL_SCL_FREQ,
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i2c->bus_freq << RTL9310_I2C_CTRL_SCL_FREQ, RTL9310_I2C_CTRL);
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// Set slave device address
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REG_MASK(i2c, 0x7f << RTL9310_I2C_CTRL_DEV_ADDR,
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addr << RTL9310_I2C_CTRL_DEV_ADDR, RTL9310_I2C_CTRL);
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// Set data length
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REG_MASK(i2c, 0xf << RTL9310_I2C_CTRL_DATA_WIDTH,
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((len - 1) & 0xf) << RTL9310_I2C_CTRL_DATA_WIDTH, RTL9310_I2C_CTRL);
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// Set read mode to random
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REG_MASK(i2c, 0x1 << RTL9310_I2C_CTRL_READ_MODE, 0, RTL9310_I2C_CTRL);
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return 0;
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}
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static int i2c_read(void __iomem *r0, u8 *buf, int len)
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{
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int i;
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u32 v;
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if (len > 16)
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return -EIO;
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for (i = 0; i < len; i++) {
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if (i % 4 == 0)
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v = readl(r0 + i);
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buf[i] = v;
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v >>= 8;
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}
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return len;
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}
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static int i2c_write(void __iomem *r0, u8 *buf, int len)
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{
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u32 v;
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int i;
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if (len > 16)
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return -EIO;
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for (i = 0; i < len; i++) {
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if (! (i % 4))
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v = 0;
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v <<= 8;
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v |= buf[i];
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if (i % 4 == 3 || i == len - 1)
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writel(v, r0 + (i / 4) * 4);
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}
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return len;
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}
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static int rtl9300_i2c_read(struct rtl9300_i2c *i2c, u8 *buf, int len)
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{
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return i2c_read(REG(i2c, RTL9300_I2C_DATA_WORD0), buf, len);
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}
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static int rtl9300_i2c_write(struct rtl9300_i2c *i2c, u8 *buf, int len)
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{
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return i2c_write(REG(i2c, RTL9300_I2C_DATA_WORD0), buf, len);
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}
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static int rtl9310_i2c_read(struct rtl9300_i2c *i2c, u8 *buf, int len)
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{
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return i2c_read(REG(i2c, RTL9310_I2C_DATA), buf, len);
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}
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static int rtl9310_i2c_write(struct rtl9300_i2c *i2c, u8 *buf, int len)
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{
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return i2c_write(REG(i2c, RTL9310_I2C_DATA), buf, len);
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}
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static void rtl9300_writel(struct rtl9300_i2c *i2c, u32 data)
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{
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writel(data, REG(i2c, RTL9300_I2C_DATA_WORD0));
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}
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static void rtl9310_writel(struct rtl9300_i2c *i2c, u32 data)
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{
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writel(data, REG(i2c, RTL9310_I2C_DATA));
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}
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static int rtl9300_execute_xfer(struct rtl9300_i2c *i2c, char read_write,
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int size, union i2c_smbus_data * data, int len)
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{
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u32 v;
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if (read_write == I2C_SMBUS_READ)
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REG_MASK(i2c, BIT(RTL9300_I2C_CTRL1_RWOP), 0, RTL9300_I2C_CTRL1);
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else
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REG_MASK(i2c, 0, BIT(RTL9300_I2C_CTRL1_RWOP), RTL9300_I2C_CTRL1);
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REG_MASK(i2c, 0, BIT(RTL9300_I2C_CTRL1_I2C_TRIG), RTL9300_I2C_CTRL1);
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do {
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v = readl(REG(i2c, RTL9300_I2C_CTRL1));
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} while (v & BIT(RTL9300_I2C_CTRL1_I2C_TRIG));
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if (v & BIT(RTL9300_I2C_CTRL1_I2C_FAIL))
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return -EIO;
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if (read_write == I2C_SMBUS_READ) {
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if (size == I2C_SMBUS_BYTE || size == I2C_SMBUS_BYTE_DATA){
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data->byte = readl(REG(i2c, RTL9300_I2C_DATA_WORD0));
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} else if (size == I2C_SMBUS_WORD_DATA) {
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data->word = readl(REG(i2c, RTL9300_I2C_DATA_WORD0));
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} else if (len > 0) {
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rtl9300_i2c_read(i2c, &data->block[0], len);
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}
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}
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return 0;
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}
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static int rtl9310_execute_xfer(struct rtl9300_i2c *i2c, char read_write,
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int size, union i2c_smbus_data * data, int len)
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{
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u32 v;
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if (read_write == I2C_SMBUS_READ)
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REG_MASK(i2c, BIT(RTL9310_I2C_CTRL_RWOP), 0, RTL9310_I2C_CTRL);
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else
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REG_MASK(i2c, 0, BIT(RTL9310_I2C_CTRL_RWOP), RTL9310_I2C_CTRL);
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REG_MASK(i2c, 0, BIT(RTL9310_I2C_CTRL_I2C_TRIG), RTL9310_I2C_CTRL);
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do {
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v = readl(REG(i2c, RTL9310_I2C_CTRL));
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} while (v & BIT(RTL9310_I2C_CTRL_I2C_TRIG));
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if (v & BIT(RTL9310_I2C_CTRL_I2C_FAIL))
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return -EIO;
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if (read_write == I2C_SMBUS_READ) {
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if (size == I2C_SMBUS_BYTE || size == I2C_SMBUS_BYTE_DATA){
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data->byte = readl(REG(i2c, RTL9310_I2C_DATA));
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} else if (size == I2C_SMBUS_WORD_DATA) {
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data->word = readl(REG(i2c, RTL9310_I2C_DATA));
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} else if (len > 0) {
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rtl9310_i2c_read(i2c, &data->block[0], len);
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}
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}
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return 0;
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}
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static int rtl9300_i2c_smbus_xfer(struct i2c_adapter * adap, u16 addr,
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unsigned short flags, char read_write,
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u8 command, int size, union i2c_smbus_data * data)
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{
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struct rtl9300_i2c *i2c = i2c_get_adapdata(adap);
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struct i2c_drv_data *drv_data = (struct i2c_drv_data *)device_get_match_data(i2c->dev);
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int len = 0, ret;
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mutex_lock(&i2c_lock);
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switch (size) {
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case I2C_SMBUS_QUICK:
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drv_data->config_xfer(i2c, addr, 0);
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drv_data->reg_addr_set(i2c, 0, 0);
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break;
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case I2C_SMBUS_BYTE:
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if (read_write == I2C_SMBUS_WRITE) {
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drv_data->config_xfer(i2c, addr, 0);
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drv_data->reg_addr_set(i2c, command, 1);
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} else {
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drv_data->config_xfer(i2c, addr, 1);
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drv_data->reg_addr_set(i2c, 0, 0);
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}
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break;
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case I2C_SMBUS_BYTE_DATA:
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pr_debug("I2C_SMBUS_BYTE_DATA %02x, read %d cmd %02x\n", addr, read_write, command);
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drv_data->reg_addr_set(i2c, command, 1);
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drv_data->config_xfer(i2c, addr, 1);
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if (read_write == I2C_SMBUS_WRITE) {
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pr_debug("--> data %02x\n", data->byte);
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drv_data->writel(i2c, data->byte);
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}
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break;
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case I2C_SMBUS_WORD_DATA:
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pr_debug("I2C_SMBUS_WORD %02x, read %d\n", addr, read_write);
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drv_data->reg_addr_set(i2c, command, 1);
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drv_data->config_xfer(i2c, addr, 2);
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if (read_write == I2C_SMBUS_WRITE)
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drv_data->writel(i2c, data->word);
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break;
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case I2C_SMBUS_BLOCK_DATA:
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pr_debug("I2C_SMBUS_BLOCK_DATA %02x, read %d, len %d\n",
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addr, read_write, data->block[0]);
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drv_data->reg_addr_set(i2c, command, 1);
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drv_data->config_xfer(i2c, addr, data->block[0]);
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if (read_write == I2C_SMBUS_WRITE)
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drv_data->write(i2c, &data->block[1], data->block[0]);
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len = data->block[0];
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break;
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default:
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dev_warn(&adap->dev, "Unsupported transaction %d\n", size);
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return -EOPNOTSUPP;
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}
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ret = drv_data->execute_xfer(i2c, read_write, size, data, len);
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mutex_unlock(&i2c_lock);
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return ret;
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}
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static u32 rtl9300_i2c_func(struct i2c_adapter *a)
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{
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return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
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I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
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I2C_FUNC_SMBUS_BLOCK_DATA;
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}
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static const struct i2c_algorithm rtl9300_i2c_algo = {
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.smbus_xfer = rtl9300_i2c_smbus_xfer,
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.functionality = rtl9300_i2c_func,
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};
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struct i2c_adapter_quirks rtl9300_i2c_quirks = {
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.flags = I2C_AQ_NO_CLK_STRETCH,
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.max_read_len = 16,
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.max_write_len = 16,
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};
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static int rtl9300_i2c_probe(struct platform_device *pdev)
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{
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struct resource *res;
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struct rtl9300_i2c *i2c;
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struct i2c_adapter *adap;
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struct i2c_drv_data *drv_data;
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struct device_node *node = pdev->dev.of_node;
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u32 clock_freq, pin;
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int ret = 0;
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pr_info("%s probing I2C adapter\n", __func__);
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if (!node) {
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dev_err(i2c->dev, "No DT found\n");
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return -EINVAL;
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}
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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drv_data = (struct i2c_drv_data *) device_get_match_data(&pdev->dev);
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i2c = devm_kzalloc(&pdev->dev, sizeof(struct rtl9300_i2c), GFP_KERNEL);
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if (!i2c)
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return -ENOMEM;
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i2c->base = devm_ioremap_resource(&pdev->dev, res);
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i2c->mst2_offset = drv_data->mst2_offset;
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if (IS_ERR(i2c->base))
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return PTR_ERR(i2c->base);
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pr_debug("%s base memory %08x\n", __func__, (u32)i2c->base);
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i2c->dev = &pdev->dev;
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if (of_property_read_u32(node, "clock-frequency", &clock_freq)) {
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clock_freq = I2C_MAX_STANDARD_MODE_FREQ;
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}
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switch(clock_freq) {
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case I2C_MAX_STANDARD_MODE_FREQ:
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i2c->bus_freq = RTL9300_I2C_STD_FREQ;
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break;
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case I2C_MAX_FAST_MODE_FREQ:
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i2c->bus_freq = RTL9300_I2C_FAST_FREQ;
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break;
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default:
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dev_warn(i2c->dev, "clock-frequency %d not supported\n", clock_freq);
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return -EINVAL;
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}
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dev_info(&pdev->dev, "SCL speed %d, mode is %d\n", clock_freq, i2c->bus_freq);
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if (of_property_read_u32(node, "scl-pin", &pin)) {
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dev_warn(i2c->dev, "SCL pin not found in DT, using default\n");
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pin = drv_data->scl0_pin;
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}
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if (!(pin == drv_data->scl0_pin || pin == drv_data->scl1_pin)) {
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dev_warn(i2c->dev, "SCL pin %d not supported\n", pin);
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return -EINVAL;
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}
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i2c->scl_num = pin == drv_data->scl0_pin ? 0 : 1;
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pr_info("%s scl_num %d\n", __func__, i2c->scl_num);
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if (of_property_read_u32(node, "sda-pin", &pin)) {
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dev_warn(i2c->dev, "SDA pin not found in DT, using default \n");
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pin = drv_data->sda0_pin;
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}
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i2c->sda_num = pin - drv_data->sda0_pin;
|
|
if (i2c->sda_num < 0 || i2c->sda_num > 7) {
|
|
dev_warn(i2c->dev, "SDA pin %d not supported\n", pin);
|
|
return -EINVAL;
|
|
}
|
|
pr_info("%s sda_num %d\n", __func__, i2c->sda_num);
|
|
|
|
adap = &i2c->adap;
|
|
adap->owner = THIS_MODULE;
|
|
adap->algo = &rtl9300_i2c_algo;
|
|
adap->retries = 3;
|
|
adap->dev.parent = &pdev->dev;
|
|
i2c_set_adapdata(adap, i2c);
|
|
adap->dev.of_node = node;
|
|
strlcpy(adap->name, dev_name(&pdev->dev), sizeof(adap->name));
|
|
|
|
platform_set_drvdata(pdev, i2c);
|
|
|
|
drv_data->config_io(i2c, i2c->scl_num, i2c->sda_num);
|
|
|
|
ret = i2c_add_adapter(adap);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int rtl9300_i2c_remove(struct platform_device *pdev)
|
|
{
|
|
struct rtl9300_i2c *i2c = platform_get_drvdata(pdev);
|
|
|
|
i2c_del_adapter(&i2c->adap);
|
|
|
|
return 0;
|
|
}
|
|
|
|
struct i2c_drv_data rtl9300_i2c_drv_data = {
|
|
.scl0_pin = 8,
|
|
.scl1_pin = 17,
|
|
.sda0_pin = 9,
|
|
.read = rtl9300_i2c_read,
|
|
.read = rtl9300_i2c_write,
|
|
.reg_addr_set = rtl9300_i2c_reg_addr_set,
|
|
.config_xfer = rtl9300_i2c_config_xfer,
|
|
.execute_xfer = rtl9300_execute_xfer,
|
|
.writel = rtl9300_writel,
|
|
.config_io = rtl9300_i2c_config_io,
|
|
.mst2_offset = 0x1c,
|
|
};
|
|
|
|
struct i2c_drv_data rtl9310_i2c_drv_data = {
|
|
.scl0_pin = 13,
|
|
.scl1_pin = 14,
|
|
.sda0_pin = 0,
|
|
.read = rtl9310_i2c_read,
|
|
.read = rtl9310_i2c_write,
|
|
.reg_addr_set = rtl9310_i2c_reg_addr_set,
|
|
.config_xfer = rtl9310_i2c_config_xfer,
|
|
.execute_xfer = rtl9310_execute_xfer,
|
|
.writel = rtl9310_writel,
|
|
.config_io = rtl9310_i2c_config_io,
|
|
.mst2_offset = 0x18,
|
|
};
|
|
|
|
static const struct of_device_id i2c_rtl9300_dt_ids[] = {
|
|
{ .compatible = "realtek,rtl9300-i2c", .data = (void *) &rtl9300_i2c_drv_data },
|
|
{ .compatible = "realtek,rtl9310-i2c", .data = (void *) &rtl9310_i2c_drv_data },
|
|
{ /* sentinel */ }
|
|
};
|
|
MODULE_DEVICE_TABLE(of, rtl838x_eth_of_ids);
|
|
|
|
static struct platform_driver rtl9300_i2c_driver = {
|
|
.probe = rtl9300_i2c_probe,
|
|
.remove = rtl9300_i2c_remove,
|
|
.driver = {
|
|
.name = "i2c-rtl9300",
|
|
.pm = NULL,
|
|
.of_match_table = i2c_rtl9300_dt_ids,
|
|
},
|
|
};
|
|
|
|
module_platform_driver(rtl9300_i2c_driver);
|
|
|
|
MODULE_AUTHOR("Birger Koblitz");
|
|
MODULE_DESCRIPTION("RTL9300 I2C host driver");
|
|
MODULE_LICENSE("GPL v2");
|