diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-designware-platdrv.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-designware-platdrv.c | 37 |
1 files changed, 36 insertions, 1 deletions
diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c index 35b70a1edf57..2da574a9f03f 100644 --- a/drivers/i2c/busses/i2c-designware-platdrv.c +++ b/drivers/i2c/busses/i2c-designware-platdrv.c @@ -34,6 +34,7 @@ #include <linux/sched.h> #include <linux/err.h> #include <linux/interrupt.h> +#include <linux/of.h> #include <linux/of_i2c.h> #include <linux/platform_device.h> #include <linux/pm.h> @@ -86,6 +87,7 @@ static int dw_i2c_probe(struct platform_device *pdev) struct i2c_adapter *adap; struct resource *mem; int irq, r; + u32 bus_rate = DW_IC_CON_SPEED_STD; /* NOTE: driver uses the static register mapping */ mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); @@ -121,6 +123,39 @@ static int dw_i2c_probe(struct platform_device *pdev) return PTR_ERR(dev->clk); clk_prepare_enable(dev->clk); + if (pdev->dev.of_node) { + u32 ht = 0; + u32 ic_clk = dev->get_clk_rate_khz(dev); + + of_property_read_u32(pdev->dev.of_node, + "i2c-sda-hold-time-ns", &ht); + dev->sda_hold_time = div_u64((u64)ic_clk * ht + 500000, + 1000000); + + of_property_read_u32(pdev->dev.of_node, + "i2c-sda-falling-time-ns", + &dev->sda_falling_time); + of_property_read_u32(pdev->dev.of_node, + "i2c-scl-falling-time-ns", + &dev->scl_falling_time); + + r = of_property_read_u32(pdev->dev.of_node, "clock-frequency", + &bus_rate); + if (r) + bus_rate = 400000; /* default clock rate */ + switch (bus_rate) { + case 400000: + bus_rate = DW_IC_CON_SPEED_FAST; + break; + case 100000: + bus_rate = DW_IC_CON_SPEED_STD; + break; + default: + dev_err(&pdev->dev, "Invalid bus speed (not 100kHz or 400kHz)\n"); + return -EINVAL; + } + } + dev->functionality = I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR | @@ -129,7 +164,7 @@ static int dw_i2c_probe(struct platform_device *pdev) I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_I2C_BLOCK; dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE | - DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST; + DW_IC_CON_RESTART_EN | bus_rate; /* Try first if we can configure the device from ACPI */ r = dw_i2c_acpi_configure(pdev); |