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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-09-08 01:01:14 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-09-08 01:01:14 -0300
commite5fd91f1ef340da553f7a79da9540c3db711c937 (patch)
treeb11842027dc6641da63f4bcc524f8678263304a3 /drivers/clk/imx/clk-pllv1.c
parent2a9b0348e685a63d97486f6749622b61e9e3292f (diff)
Linux-libre 4.2-gnu
Diffstat (limited to 'drivers/clk/imx/clk-pllv1.c')
-rw-r--r--drivers/clk/imx/clk-pllv1.c141
1 files changed, 141 insertions, 0 deletions
diff --git a/drivers/clk/imx/clk-pllv1.c b/drivers/clk/imx/clk-pllv1.c
new file mode 100644
index 000000000..c34ad8a61
--- /dev/null
+++ b/drivers/clk/imx/clk-pllv1.c
@@ -0,0 +1,141 @@
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+#include <linux/kernel.h>
+#include <linux/err.h>
+
+#include "clk.h"
+
+/**
+ * pll v1
+ *
+ * @clk_hw clock source
+ * @parent the parent clock name
+ * @base base address of pll registers
+ *
+ * PLL clock version 1, found on i.MX1/21/25/27/31/35
+ */
+
+#define MFN_BITS (10)
+#define MFN_SIGN (BIT(MFN_BITS - 1))
+#define MFN_MASK (MFN_SIGN - 1)
+
+struct clk_pllv1 {
+ struct clk_hw hw;
+ void __iomem *base;
+ enum imx_pllv1_type type;
+};
+
+#define to_clk_pllv1(clk) (container_of(clk, struct clk_pllv1, clk))
+
+static inline bool is_imx1_pllv1(struct clk_pllv1 *pll)
+{
+ return pll->type == IMX_PLLV1_IMX1;
+}
+
+static inline bool is_imx21_pllv1(struct clk_pllv1 *pll)
+{
+ return pll->type == IMX_PLLV1_IMX21;
+}
+
+static inline bool is_imx27_pllv1(struct clk_pllv1 *pll)
+{
+ return pll->type == IMX_PLLV1_IMX27;
+}
+
+static inline bool mfn_is_negative(struct clk_pllv1 *pll, unsigned int mfn)
+{
+ return !is_imx1_pllv1(pll) && !is_imx21_pllv1(pll) && (mfn & MFN_SIGN);
+}
+
+static unsigned long clk_pllv1_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct clk_pllv1 *pll = to_clk_pllv1(hw);
+ long long ll;
+ int mfn_abs;
+ unsigned int mfi, mfn, mfd, pd;
+ u32 reg;
+ unsigned long rate;
+
+ reg = readl(pll->base);
+
+ /*
+ * Get the resulting clock rate from a PLL register value and the input
+ * frequency. PLLs with this register layout can be found on i.MX1,
+ * i.MX21, i.MX27 and i,MX31
+ *
+ * mfi + mfn / (mfd + 1)
+ * f = 2 * f_ref * --------------------
+ * pd + 1
+ */
+
+ mfi = (reg >> 10) & 0xf;
+ mfn = reg & 0x3ff;
+ mfd = (reg >> 16) & 0x3ff;
+ pd = (reg >> 26) & 0xf;
+
+ mfi = mfi <= 5 ? 5 : mfi;
+
+ mfn_abs = mfn;
+
+ /*
+ * On all i.MXs except i.MX1 and i.MX21 mfn is a 10bit
+ * 2's complements number.
+ * On i.MX27 the bit 9 is the sign bit.
+ */
+ if (mfn_is_negative(pll, mfn)) {
+ if (is_imx27_pllv1(pll))
+ mfn_abs = mfn & MFN_MASK;
+ else
+ mfn_abs = BIT(MFN_BITS) - mfn;
+ }
+
+ rate = parent_rate * 2;
+ rate /= pd + 1;
+
+ ll = (unsigned long long)rate * mfn_abs;
+
+ do_div(ll, mfd + 1);
+
+ if (mfn_is_negative(pll, mfn))
+ ll = -ll;
+
+ ll = (rate * mfi) + ll;
+
+ return ll;
+}
+
+static struct clk_ops clk_pllv1_ops = {
+ .recalc_rate = clk_pllv1_recalc_rate,
+};
+
+struct clk *imx_clk_pllv1(enum imx_pllv1_type type, const char *name,
+ const char *parent, void __iomem *base)
+{
+ struct clk_pllv1 *pll;
+ struct clk *clk;
+ struct clk_init_data init;
+
+ pll = kmalloc(sizeof(*pll), GFP_KERNEL);
+ if (!pll)
+ return ERR_PTR(-ENOMEM);
+
+ pll->base = base;
+ pll->type = type;
+
+ init.name = name;
+ init.ops = &clk_pllv1_ops;
+ init.flags = 0;
+ init.parent_names = &parent;
+ init.num_parents = 1;
+
+ pll->hw.init = &init;
+
+ clk = clk_register(NULL, &pll->hw);
+ if (IS_ERR(clk))
+ kfree(pll);
+
+ return clk;
+}