Patrick Williams 於 31/05/2022 9:47 pm 寫道:
> On Mon, May 30, 2022 at 07:40:56PM +0800, Potin Lai wrote:
>> From: Porin Lai <potin.lai.pt@xxxxxxxxx>
>>
>> Add properties for manual tuning i2c clock timing register.
>>
>> * aspeed,i2c-manual-clk: Enable aspeed i2c clock manual setup
>> * aspeed,i2c-base-clk-div: Base Clock divisor (tBaseClk)
>> * aspeed,i2c-clk-high-cycle: Cycles of clock-high pulse (tClkHigh)
>> * aspeed,i2c-clk-low-cycle: Cycles of clock-low pulse (tClkLow)
> Do we need to add these to
> Documentation/devicetree/bindings/i2c/aspeed,i2c.yaml ?
Sorry, I wasn't notice the yaml file, I will update the documentation in next version.
Potin
>> Signed-off-by: Potin Lai <potin.lai.pt@xxxxxxxxx>
>> ---
>> drivers/i2c/busses/i2c-aspeed.c | 55 ++++++++++++++++++++++++++++++++-
>> 1 file changed, 54 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/i2c/busses/i2c-aspeed.c b/drivers/i2c/busses/i2c-aspeed.c
>> index 67e8b97c0c95..1f4b5c4b5bf4 100644
>> --- a/drivers/i2c/busses/i2c-aspeed.c
>> +++ b/drivers/i2c/busses/i2c-aspeed.c
>> @@ -898,6 +898,56 @@ static int aspeed_i2c_init_clk(struct aspeed_i2c_bus *bus)
>> return 0;
>> }
>>
>> +/* precondition: bus.lock has been acquired. */
>> +static int aspeed_i2c_manual_clk_setup(struct aspeed_i2c_bus *bus)
>> +{
>> + u32 divisor, clk_high, clk_low, clk_reg_val;
>> +
>> + if (device_property_read_u32(bus->dev, "aspeed,i2c-base-clk-div",
>> + &divisor) != 0) {
>> + dev_err(bus->dev, "Could not read aspeed,i2c-base-clk-div\n");
>> + return -EINVAL;
>> + } else if (divisor > ASPEED_I2CD_TIME_BASE_DIVISOR_MASK) {
>> + dev_err(bus->dev, "Invalid aspeed,i2c-base-clk-div: %u\n",
>> + divisor);
>> + return -EINVAL;
>> + }
>> +
>> + if (device_property_read_u32(bus->dev, "aspeed,i2c-clk-high-cycle",
>> + &clk_high) != 0) {
>> + dev_err(bus->dev, "Could not read aspeed,i2c-clk-high-cycle\n");
>> + return -EINVAL;
>> + } else if (clk_high > ASPEED_I2CD_TIME_SCL_REG_MAX) {
>> + dev_err(bus->dev, "Invalid aspeed,i2c-clk-high-cycle: %u\n",
>> + clk_high);
>> + return -EINVAL;
>> + }
>> +
>> + if (device_property_read_u32(bus->dev, "aspeed,i2c-clk-low-cycle",
>> + &clk_low) != 0) {
>> + dev_err(bus->dev, "Could not read aspeed,i2c-clk-low-cycle\n");
>> + return -EINVAL;
>> + } else if (clk_low > ASPEED_I2CD_TIME_SCL_REG_MAX) {
>> + dev_err(bus->dev, "Invalid aspeed,i2c-clk-low-cycle: %u\n",
>> + clk_low);
>> + return -EINVAL;
>> + }
>> +
>> + clk_reg_val = readl(bus->base + ASPEED_I2C_AC_TIMING_REG1);
>> + clk_reg_val &= (ASPEED_I2CD_TIME_TBUF_MASK |
>> + ASPEED_I2CD_TIME_THDSTA_MASK |
>> + ASPEED_I2CD_TIME_TACST_MASK);
>> + clk_reg_val |= (divisor & ASPEED_I2CD_TIME_BASE_DIVISOR_MASK)
>> + | ((clk_high << ASPEED_I2CD_TIME_SCL_HIGH_SHIFT)
>> + & ASPEED_I2CD_TIME_SCL_HIGH_MASK)
>> + | ((clk_low << ASPEED_I2CD_TIME_SCL_LOW_SHIFT)
>> + & ASPEED_I2CD_TIME_SCL_LOW_MASK);
>> + writel(clk_reg_val, bus->base + ASPEED_I2C_AC_TIMING_REG1);
>> + writel(ASPEED_NO_TIMEOUT_CTRL, bus->base + ASPEED_I2C_AC_TIMING_REG2);
>> +
>> + return 0;
>> +}
>> +
>> /* precondition: bus.lock has been acquired. */
>> static int aspeed_i2c_init(struct aspeed_i2c_bus *bus,
>> struct platform_device *pdev)
>> @@ -908,7 +958,10 @@ static int aspeed_i2c_init(struct aspeed_i2c_bus *bus,
>> /* Disable everything. */
>> writel(0, bus->base + ASPEED_I2C_FUN_CTRL_REG);
>>
>> - ret = aspeed_i2c_init_clk(bus);
>> + if (of_property_read_bool(pdev->dev.of_node, "aspeed,i2c-manual-clk"))
>> + ret = aspeed_i2c_manual_clk_setup(bus);
>> + else
>> + ret = aspeed_i2c_init_clk(bus);
>> if (ret < 0)
>> return ret;
>>
>> --
>> 2.17.1
>>
