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148 lines
3.1 KiB
C
148 lines
3.1 KiB
C
/*
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* Copyright 2012 Freescale Semiconductor, Inc.
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* Copyright 2012 Linaro Ltd.
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*
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* The code contained herein is licensed under the GNU General Public
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* License. You may obtain a copy of the GNU General Public License
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* Version 2 or later at the following locations:
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*
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* http://www.opensource.org/licenses/gpl-license.html
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* http://www.gnu.org/copyleft/gpl.html
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*/
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#include <linux/clk.h>
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#include <linux/clk-provider.h>
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#include <linux/io.h>
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#include <linux/slab.h>
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#include <linux/err.h>
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#include "clk.h"
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/**
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* struct clk_pfd - IMX PFD clock
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* @clk_hw: clock source
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* @reg: PFD register address
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* @idx: the index of PFD encoded in the register
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*
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* PFD clock found on i.MX6 series. Each register for PFD has 4 clk_pfd
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* data encoded, and member idx is used to specify the one. And each
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* register has SET, CLR and TOG registers at offset 0x4 0x8 and 0xc.
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*/
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struct clk_pfd {
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struct clk_hw hw;
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void __iomem *reg;
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u8 idx;
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};
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#define to_clk_pfd(_hw) container_of(_hw, struct clk_pfd, hw)
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#define SET 0x4
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#define CLR 0x8
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#define OTG 0xc
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static int clk_pfd_enable(struct clk_hw *hw)
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{
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struct clk_pfd *pfd = to_clk_pfd(hw);
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writel_relaxed(1 << ((pfd->idx + 1) * 8 - 1), pfd->reg + CLR);
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return 0;
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}
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static void clk_pfd_disable(struct clk_hw *hw)
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{
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struct clk_pfd *pfd = to_clk_pfd(hw);
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writel_relaxed(1 << ((pfd->idx + 1) * 8 - 1), pfd->reg + SET);
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}
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static unsigned long clk_pfd_recalc_rate(struct clk_hw *hw,
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unsigned long parent_rate)
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{
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struct clk_pfd *pfd = to_clk_pfd(hw);
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u64 tmp = parent_rate;
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u8 frac = (readl_relaxed(pfd->reg) >> (pfd->idx * 8)) & 0x3f;
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tmp *= 18;
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do_div(tmp, frac);
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return tmp;
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}
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static long clk_pfd_round_rate(struct clk_hw *hw, unsigned long rate,
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unsigned long *prate)
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{
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u64 tmp = *prate;
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u8 frac;
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tmp = tmp * 18 + rate / 2;
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do_div(tmp, rate);
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frac = tmp;
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if (frac < 12)
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frac = 12;
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else if (frac > 35)
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frac = 35;
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tmp = *prate;
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tmp *= 18;
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do_div(tmp, frac);
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return tmp;
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}
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static int clk_pfd_set_rate(struct clk_hw *hw, unsigned long rate,
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unsigned long parent_rate)
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{
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struct clk_pfd *pfd = to_clk_pfd(hw);
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u64 tmp = parent_rate;
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u8 frac;
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tmp = tmp * 18 + rate / 2;
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do_div(tmp, rate);
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frac = tmp;
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if (frac < 12)
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frac = 12;
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else if (frac > 35)
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frac = 35;
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writel_relaxed(0x3f << (pfd->idx * 8), pfd->reg + CLR);
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writel_relaxed(frac << (pfd->idx * 8), pfd->reg + SET);
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return 0;
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}
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static const struct clk_ops clk_pfd_ops = {
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.enable = clk_pfd_enable,
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.disable = clk_pfd_disable,
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.recalc_rate = clk_pfd_recalc_rate,
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.round_rate = clk_pfd_round_rate,
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.set_rate = clk_pfd_set_rate,
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};
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struct clk *imx_clk_pfd(const char *name, const char *parent_name,
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void __iomem *reg, u8 idx)
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{
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struct clk_pfd *pfd;
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struct clk *clk;
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struct clk_init_data init;
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pfd = kzalloc(sizeof(*pfd), GFP_KERNEL);
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if (!pfd)
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return ERR_PTR(-ENOMEM);
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pfd->reg = reg;
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pfd->idx = idx;
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init.name = name;
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init.ops = &clk_pfd_ops;
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init.flags = 0;
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init.parent_names = &parent_name;
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init.num_parents = 1;
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pfd->hw.init = &init;
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clk = clk_register(NULL, &pfd->hw);
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if (IS_ERR(clk))
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kfree(pfd);
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return clk;
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}
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