diff options
Diffstat (limited to 'drivers/cpufreq')
| -rw-r--r-- | drivers/cpufreq/imx6q-cpufreq.c | 50 |
1 files changed, 45 insertions, 5 deletions
diff --git a/drivers/cpufreq/imx6q-cpufreq.c b/drivers/cpufreq/imx6q-cpufreq.c index 380a90d3c57e..9b4a7bd04dea 100644 --- a/drivers/cpufreq/imx6q-cpufreq.c +++ b/drivers/cpufreq/imx6q-cpufreq.c @@ -30,6 +30,10 @@ static struct clk *pll1_sw_clk; static struct clk *step_clk; static struct clk *pll2_pfd2_396m_clk; +/* clk used by i.MX6UL */ +static struct clk *pll2_bus_clk; +static struct clk *secondary_sel_clk; + static struct device *cpu_dev; static bool free_opp; static struct cpufreq_frequency_table *freq_table; @@ -91,16 +95,36 @@ static int imx6q_set_target(struct cpufreq_policy *policy, unsigned int index) * The setpoints are selected per PLL/PDF frequencies, so we need to * reprogram PLL for frequency scaling. The procedure of reprogramming * PLL1 is as below. - * + * For i.MX6UL, it has a secondary clk mux, the cpu frequency change + * flow is slightly different from other i.MX6 OSC. + * The cpu frequeny change flow for i.MX6(except i.MX6UL) is as below: * - Enable pll2_pfd2_396m_clk and reparent pll1_sw_clk to it * - Reprogram pll1_sys_clk and reparent pll1_sw_clk back to it * - Disable pll2_pfd2_396m_clk */ - clk_set_parent(step_clk, pll2_pfd2_396m_clk); - clk_set_parent(pll1_sw_clk, step_clk); - if (freq_hz > clk_get_rate(pll2_pfd2_396m_clk)) { - clk_set_rate(pll1_sys_clk, new_freq * 1000); + if (of_machine_is_compatible("fsl,imx6ul")) { + /* + * When changing pll1_sw_clk's parent to pll1_sys_clk, + * CPU may run at higher than 528MHz, this will lead to + * the system unstable if the voltage is lower than the + * voltage of 528MHz, so lower the CPU frequency to one + * half before changing CPU frequency. + */ + clk_set_rate(arm_clk, (old_freq >> 1) * 1000); clk_set_parent(pll1_sw_clk, pll1_sys_clk); + if (freq_hz > clk_get_rate(pll2_pfd2_396m_clk)) + clk_set_parent(secondary_sel_clk, pll2_bus_clk); + else + clk_set_parent(secondary_sel_clk, pll2_pfd2_396m_clk); + clk_set_parent(step_clk, secondary_sel_clk); + clk_set_parent(pll1_sw_clk, step_clk); + } else { + clk_set_parent(step_clk, pll2_pfd2_396m_clk); + clk_set_parent(pll1_sw_clk, step_clk); + if (freq_hz > clk_get_rate(pll2_pfd2_396m_clk)) { + clk_set_rate(pll1_sys_clk, new_freq * 1000); + clk_set_parent(pll1_sw_clk, pll1_sys_clk); + } } /* Ensure the arm clock divider is what we expect */ @@ -186,6 +210,16 @@ static int imx6q_cpufreq_probe(struct platform_device *pdev) goto put_clk; } + if (of_machine_is_compatible("fsl,imx6ul")) { + pll2_bus_clk = clk_get(cpu_dev, "pll2_bus"); + secondary_sel_clk = clk_get(cpu_dev, "secondary_sel"); + if (IS_ERR(pll2_bus_clk) || IS_ERR(secondary_sel_clk)) { + dev_err(cpu_dev, "failed to get clocks specific to imx6ul\n"); + ret = -ENOENT; + goto put_clk; + } + } + arm_reg = regulator_get(cpu_dev, "arm"); pu_reg = regulator_get_optional(cpu_dev, "pu"); soc_reg = regulator_get(cpu_dev, "soc"); @@ -331,6 +365,10 @@ put_clk: clk_put(step_clk); if (!IS_ERR(pll2_pfd2_396m_clk)) clk_put(pll2_pfd2_396m_clk); + if (!IS_ERR(pll2_bus_clk)) + clk_put(pll2_bus_clk); + if (!IS_ERR(secondary_sel_clk)) + clk_put(secondary_sel_clk); of_node_put(np); return ret; } @@ -350,6 +388,8 @@ static int imx6q_cpufreq_remove(struct platform_device *pdev) clk_put(pll1_sw_clk); clk_put(step_clk); clk_put(pll2_pfd2_396m_clk); + clk_put(pll2_bus_clk); + clk_put(secondary_sel_clk); return 0; } |