Hi, Marek,
On Thu, Jul 14, 2011 at 5:58 AM, Marek Vasut <[email protected]> wrote:
> Rewrite the mxc_i2c driver.
> * This version is much closer to Linux implementation.
> * Fixes IPG_PERCLK being incorrectly used as clock source
> * Fixes behaviour of the driver on iMX51
> * Clean up coding style a bit ;-)
>
why you change i2c clock from IPG_PERCLK to IPG_CLK?
[...]
> +static void i2c_imx_set_clk(unsigned int rate)
> {
> - int freq;
> + struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)I2C_BASE;
> + unsigned int i2c_clk_rate;
> + unsigned int div;
> int i;
>
> + /* Divider value calculation */
> #if defined(CONFIG_MX31)
> struct clock_control_regs *sc_regs =
> (struct clock_control_regs *)CCM_BASE;
>
> - freq = mx31_get_ipg_clk();
> + i2c_clk_rate = mx31_get_ipg_clk();
> /* start the required I2C clock */
> writel(readl(&sc_regs->cgr0) | (3 << I2C_CLK_OFFSET),
> &sc_regs->cgr0);
> #else
> - freq = mxc_get_clock(MXC_IPG_PERCLK);
> + i2c_clk_rate = mxc_get_clock(MXC_IPG_CLK);
> #endif
There are two clocks for i2c:
Peripheral clock (IPBus): source from ipg_clk_root, which is for IP
bus register read/write.
Block clock: source from perclk_root, which is I2C function clock.
We need get perclk not ipg clock, right?
BTW, do you test this driver on mx53?
Jason
>
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