clk: tegra: Model oscillator as clock

Currently the Tegra clock driver simplifies the clock tree somewhat by
taking advantage of the fact that clk_m runs at the same frequency as
the oscillator. While that's true on all currently supported SoCs, it
does not apply to Tegra210 anymore. On Tegra210 clk_m is typically
divided down from the oscillator frequency. To support that setup, add
a separate clock for the oscillator that both clk_m and pll_ref derive
from.

Modify the tegra_osc_clk_init() function to take an additional divider
parameter for clk_m. Existing SoCs always pass in 1, whereas Tegra210
will read the divider from a register in the clock & reset controller.

Signed-off-by: Thierry Reding <treding@nvidia.com>

diff --git a/drivers/clk/tegra/clk-tegra-fixed.c b/drivers/clk/tegra/clk-tegra-fixed.c
index f3b7738..605676d 100644 (file)
--- a/drivers/clk/tegra/clk-tegra-fixed.c
+++ b/drivers/clk/tegra/clk-tegra-fixed.c
@@ -30,13 +30,12 @@
 #define OSC_CTRL_OSC_FREQ_SHIFT                28
 #define OSC_CTRL_PLL_REF_DIV_SHIFT     26
 
-int __init tegra_osc_clk_init(void __iomem *clk_base,
-                               struct tegra_clk *tegra_clks,
-                               unsigned long *input_freqs, int num,
-                               unsigned long *osc_freq,
-                               unsigned long *pll_ref_freq)
+int __init tegra_osc_clk_init(void __iomem *clk_base, struct tegra_clk *clks,
+                             unsigned long *input_freqs, unsigned int num,
+                             unsigned int clk_m_div, unsigned long *osc_freq,
+                             unsigned long *pll_ref_freq)
 {
-       struct clk *clk;
+       struct clk *clk, *osc;
        struct clk **dt_clk;
        u32 val, pll_ref_div;
        unsigned osc_idx;
@@ -54,22 +53,25 @@ int __init tegra_osc_clk_init(void __iomem *clk_base,
                return -EINVAL;
        }
 
-       dt_clk = tegra_lookup_dt_id(tegra_clk_clk_m, tegra_clks);
+       osc = clk_register_fixed_rate(NULL, "osc", NULL, CLK_IS_ROOT,
+                                     *osc_freq);
+
+       dt_clk = tegra_lookup_dt_id(tegra_clk_clk_m, clks);
        if (!dt_clk)
                return 0;
 
-       clk = clk_register_fixed_rate(NULL, "clk_m", NULL, CLK_IS_ROOT,
-                                     *osc_freq);
+       clk = clk_register_fixed_factor(NULL, "clk_m", "osc",
+                                       0, 1, clk_m_div);
        *dt_clk = clk;
 
        /* pll_ref */
        val = (val >> OSC_CTRL_PLL_REF_DIV_SHIFT) & 3;
        pll_ref_div = 1 << val;
-       dt_clk = tegra_lookup_dt_id(tegra_clk_pll_ref, tegra_clks);
+       dt_clk = tegra_lookup_dt_id(tegra_clk_pll_ref, clks);
        if (!dt_clk)
                return 0;
 
-       clk = clk_register_fixed_factor(NULL, "pll_ref", "clk_m",
+       clk = clk_register_fixed_factor(NULL, "pll_ref", "osc",
                                        0, 1, pll_ref_div);
        *dt_clk = clk;
 

diff --git a/drivers/clk/tegra/clk-tegra124.c b/drivers/clk/tegra/clk-tegra124.c
index 29b39c8..f1fa29e 100644 (file)
--- a/drivers/clk/tegra/clk-tegra124.c
+++ b/drivers/clk/tegra/clk-tegra124.c
@@ -1480,7 +1480,8 @@ static void __init tegra124_132_clock_init_pre(struct device_node *np)
                return;
 
        if (tegra_osc_clk_init(clk_base, tegra124_clks, tegra124_input_freq,
-               ARRAY_SIZE(tegra124_input_freq), &osc_freq, &pll_ref_freq) < 0)
+                              ARRAY_SIZE(tegra124_input_freq), 1, &osc_freq,
+                              &pll_ref_freq) < 0)
                return;
 
        tegra_fixed_clk_init(tegra124_clks);

diff --git a/drivers/clk/tegra/clk-tegra30.c b/drivers/clk/tegra/clk-tegra30.c
index 0659db7..4b26509 100644 (file)
--- a/drivers/clk/tegra/clk-tegra30.c
+++ b/drivers/clk/tegra/clk-tegra30.c
@@ -1434,7 +1434,8 @@ static void __init tegra30_clock_init(struct device_node *np)
                return;
 
        if (tegra_osc_clk_init(clk_base, tegra30_clks, tegra30_input_freq,
-               ARRAY_SIZE(tegra30_input_freq), &input_freq, NULL) < 0)
+                              ARRAY_SIZE(tegra30_input_freq), 1, &input_freq,
+                              NULL) < 0)
                return;
 
 

diff --git a/drivers/clk/tegra/clk.h b/drivers/clk/tegra/clk.h
index 48cb1c1..d6ac006 100644 (file)
--- a/drivers/clk/tegra/clk.h
+++ b/drivers/clk/tegra/clk.h
@@ -615,10 +615,10 @@ void tegra_periph_clk_init(void __iomem *clk_base, void __iomem *pmc_base,
 
 void tegra_pmc_clk_init(void __iomem *pmc_base, struct tegra_clk *tegra_clks);
 void tegra_fixed_clk_init(struct tegra_clk *tegra_clks);
-int tegra_osc_clk_init(void __iomem *clk_base, struct tegra_clk *tegra_clks,
-                               unsigned long *input_freqs, int num,
-                               unsigned long *osc_freq,
-                               unsigned long *pll_ref_freq);
+int tegra_osc_clk_init(void __iomem *clk_base, struct tegra_clk *clks,
+                      unsigned long *input_freqs, unsigned int num,
+                      unsigned int clk_m_div, unsigned long *osc_freq,
+                      unsigned long *pll_ref_freq);
 void tegra_super_clk_gen4_init(void __iomem *clk_base,
                        void __iomem *pmc_base, struct tegra_clk *tegra_clks,
                        struct tegra_clk_pll_params *pll_params);