Re: [PATCH 1/5] clk: berlin: add common pll driver
From: Stephen Boyd <hidden>
Date: 2015-10-01 22:32:24
Also in:
linux-arm-kernel, linux-clk, lkml
On 09/22, Jisheng Zhang wrote:
quoted hunk ↗ jump to hunk
diff --git a/drivers/clk/berlin/pll.c b/drivers/clk/berlin/pll.c new file mode 100644 index 0000000..9aad0b6 --- /dev/null +++ b/drivers/clk/berlin/pll.c@@ -0,0 +1,119 @@ + +#define to_berlin_pll(hw) container_of(hw, struct berlin_pll, hw) + +static u8 vcodiv_berlin[] = {1, 2, 4, 8, 16, 32, 64, 128};
This is an array of 1 << index position...
+
+static unsigned long berlin_pll_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ u32 val, fbdiv, rfdiv, vcodivsel, bypass;
+ struct berlin_pll *pll = to_berlin_pll(hw);
+
+ bypass = readl_relaxed(pll->bypass);
+ if (bypass & (1 << pll->bypass_shift))
+ return parent_rate;
+
+ val = readl_relaxed(pll->ctrl + PLL_CTRL0);
+ fbdiv = (val >> 12) & 0x1FF;
+ rfdiv = (val >> 3) & 0x1FF;
+ val = readl_relaxed(pll->ctrl + PLL_CTRL1);
+ vcodivsel = (val >> 9) & 0x7;
+ return parent_rate * fbdiv * 4 / rfdiv /
+ vcodiv_berlin[vcodivsel];so we can replace this with 1 << vcodivsel?
+}
+
+static u8 berlin_pll_get_parent(struct clk_hw *hw)
+{
+ struct berlin_pll *pll = to_berlin_pll(hw);
+ u32 bypass = readl_relaxed(pll->bypass);
+
+ if (bypass & (1 << pll->bypass_shift))
+ return 1;
+ else
+ return 0;Simplify this to if (bypass & (1 << pll->bypass_shift)) return 1; return 0; or return !!(bypass & (1 << pll->bypass_shift))
+}
+
+static const struct clk_ops berlin_pll_ops = {
+ .recalc_rate = berlin_pll_recalc_rate,
+ .get_parent = berlin_pll_get_parent,
+};
+
+void __init berlin_pll_setup(struct device_node *np)static?
+{
+ struct clk_init_data init;
+ struct berlin_pll *pll;
+ const char *parent_names[PLL_SOURCE_MAX];
+ struct clk *clk;
+ int ret, num_parents;
+
+ num_parents = of_clk_get_parent_count(np);
+ if (num_parents <= 0 || num_parents > PLL_SOURCE_MAX)
+ return;
+
+ of_clk_parent_fill(np, parent_names, num_parents);
+
+ pll = kzalloc(sizeof(*pll), GFP_KERNEL);
+ if (WARN_ON(!pll))We already print a big warning on allocation failures, so drop the WARN_ON please.
+ return; + + pll->ctrl = of_iomap(np, 0); + pll->bypass = of_iomap(np, 1); + ret = of_property_read_u8(np, "bypass-shift", &pll->bypass_shift); + if (WARN_ON(!pll->ctrl || !pll->bypass || ret)) + return; + + init.name = np->name; + init.ops = &berlin_pll_ops; + init.parent_names = parent_names; + init.num_parents = num_parents;
init.flags is not initialized. Please initialize the init struct on the stack to 0 to avoid future problems.
+ + pll->hw.init = &init; + + clk = clk_register(NULL, &pll->hw); + if (WARN_ON(IS_ERR(clk))) + return; + + ret = of_clk_add_provider(np, of_clk_src_simple_get, clk); + if (WARN_ON(ret)) + return;
This return is useless.
+}
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