Use the new FSI device local bus clock to calculate the proper i2c clock divder and look up an optional clock-frequency property from device tree. Change the default clock divider to 7 now that the default local bus clock divider has been reduced as well. Signed-off-by: Eddie James <eajames@xxxxxxxxxxxxx> --- drivers/i2c/busses/i2c-fsi.c | 21 +++++++++++++++++++-- 1 file changed, 19 insertions(+), 2 deletions(-) diff --git a/drivers/i2c/busses/i2c-fsi.c b/drivers/i2c/busses/i2c-fsi.c index 10332693edf0..eaecf156ac31 100644 --- a/drivers/i2c/busses/i2c-fsi.c +++ b/drivers/i2c/busses/i2c-fsi.c @@ -27,7 +27,8 @@ #define FSI_ENGID_I2C 0x7 -#define I2C_DEFAULT_CLK_DIV 6 +#define I2C_DEFAULT_CLK_DIV 7 +#define I2C_DEFAULT_CLK_RATE 400000 /* i2c registers */ #define I2C_FSI_FIFO 0x00 @@ -150,6 +151,7 @@ struct fsi_i2c_master { u8 fifo_size; struct list_head ports; struct mutex lock; + u32 clock_div; }; struct fsi_i2c_port { @@ -194,7 +196,7 @@ static int fsi_i2c_dev_init(struct fsi_i2c_master *i2c) if (rc) return rc; - mode |= FIELD_PREP(I2C_MODE_CLKDIV, I2C_DEFAULT_CLK_DIV); + mode |= FIELD_PREP(I2C_MODE_CLKDIV, i2c->clock_div); rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_MODE, &mode); if (rc) return rc; @@ -680,6 +682,7 @@ static int fsi_i2c_probe(struct device *dev) struct fsi_i2c_port *port; struct device_node *np; u32 port_no, ports, stat; + u32 lbus; int rc; i2c = devm_kzalloc(dev, sizeof(*i2c), GFP_KERNEL); @@ -689,6 +692,20 @@ static int fsi_i2c_probe(struct device *dev) mutex_init(&i2c->lock); i2c->fsi = to_fsi_dev(dev); INIT_LIST_HEAD(&i2c->ports); + i2c->clock_div = I2C_DEFAULT_CLK_DIV; + + lbus = fsi_device_local_bus_frequency(i2c->fsi); + if (lbus) { + u32 clock = I2C_DEFAULT_CLK_RATE; + + if (!device_property_read_u32(dev, "clock-frequency", &clock)) { + if (!clock) + clock = I2C_DEFAULT_CLK_RATE; + } + + // i2c clock rate = local bus clock / (4 * (i2c clock div + 1)) + i2c->clock_div = (((lbus + (clock - 1)) / clock) / 4) - 1; + } rc = fsi_i2c_dev_init(i2c); if (rc) -- 2.39.3