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author | 2015-08-04 12:17:53 -0700 | |
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committer | 2015-08-04 15:44:42 -0700 | |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/arch/arm/mach-imx/clk-pllv1.c | |
parent | 98260f3884f4a202f9ca5eabed40b1354c489b29 (diff) |
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base.
It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:
commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Sat Jul 25 12:13:34 2015 +0200
Prepare v4.1.3-rt3
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.
Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/arch/arm/mach-imx/clk-pllv1.c')
-rw-r--r-- | kernel/arch/arm/mach-imx/clk-pllv1.c | 126 |
1 files changed, 126 insertions, 0 deletions
diff --git a/kernel/arch/arm/mach-imx/clk-pllv1.c b/kernel/arch/arm/mach-imx/clk-pllv1.c new file mode 100644 index 000000000..d21d14ca4 --- /dev/null +++ b/kernel/arch/arm/mach-imx/clk-pllv1.c @@ -0,0 +1,126 @@ +#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" +#include "common.h" +#include "hardware.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; +}; + +#define to_clk_pllv1(clk) (container_of(clk, struct clk_pllv1, clk)) + +static inline bool mfn_is_negative(unsigned int mfn) +{ + return !cpu_is_mx1() && !cpu_is_mx21() && (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(mfn)) { + if (cpu_is_mx27()) + 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(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(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; + + 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; +} |