Hi, Marek,
On Thu, Jul 14, 2011 at 5:58 AM, Marek Vasut marek.vasut@gmail.com 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