1 // SPDX-License-Identifier: GPL-2.0 2 #include <linux/bits.h> 3 #include <linux/clk-provider.h> 4 #include <linux/io.h> 5 #include <linux/slab.h> 6 #include <linux/kernel.h> 7 #include <linux/err.h> 8 9 #include "clk.h" 10 11 #define MFN_BITS (10) 12 #define MFN_SIGN (BIT(MFN_BITS - 1)) 13 #define MFN_MASK (MFN_SIGN - 1) 14 15 /** 16 * struct clk_pllv1 - IMX PLLv1 clock descriptor 17 * 18 * @hw: clock source 19 * @base: base address of pll registers 20 * @type: type of IMX_PLLV1 21 * 22 * PLL clock version 1, found on i.MX1/21/25/27/31/35 23 */ 24 struct clk_pllv1 { 25 struct clk_hw hw; 26 void __iomem *base; 27 enum imx_pllv1_type type; 28 }; 29 30 #define to_clk_pllv1(clk) (container_of(clk, struct clk_pllv1, clk)) 31 32 static inline bool is_imx1_pllv1(struct clk_pllv1 *pll) 33 { 34 return pll->type == IMX_PLLV1_IMX1; 35 } 36 37 static inline bool is_imx21_pllv1(struct clk_pllv1 *pll) 38 { 39 return pll->type == IMX_PLLV1_IMX21; 40 } 41 42 static inline bool is_imx27_pllv1(struct clk_pllv1 *pll) 43 { 44 return pll->type == IMX_PLLV1_IMX27; 45 } 46 47 static inline bool mfn_is_negative(struct clk_pllv1 *pll, unsigned int mfn) 48 { 49 return !is_imx1_pllv1(pll) && !is_imx21_pllv1(pll) && (mfn & MFN_SIGN); 50 } 51 52 static unsigned long clk_pllv1_recalc_rate(struct clk_hw *hw, 53 unsigned long parent_rate) 54 { 55 struct clk_pllv1 *pll = to_clk_pllv1(hw); 56 unsigned long long ull; 57 int mfn_abs; 58 unsigned int mfi, mfn, mfd, pd; 59 u32 reg; 60 unsigned long rate; 61 62 reg = readl(pll->base); 63 64 /* 65 * Get the resulting clock rate from a PLL register value and the input 66 * frequency. PLLs with this register layout can be found on i.MX1, 67 * i.MX21, i.MX27 and i,MX31 68 * 69 * mfi + mfn / (mfd + 1) 70 * f = 2 * f_ref * -------------------- 71 * pd + 1 72 */ 73 74 mfi = (reg >> 10) & 0xf; 75 mfn = reg & 0x3ff; 76 mfd = (reg >> 16) & 0x3ff; 77 pd = (reg >> 26) & 0xf; 78 79 mfi = mfi <= 5 ? 5 : mfi; 80 81 mfn_abs = mfn; 82 83 /* 84 * On all i.MXs except i.MX1 and i.MX21 mfn is a 10bit 85 * 2's complements number. 86 * On i.MX27 the bit 9 is the sign bit. 87 */ 88 if (mfn_is_negative(pll, mfn)) { 89 if (is_imx27_pllv1(pll)) 90 mfn_abs = mfn & MFN_MASK; 91 else 92 mfn_abs = BIT(MFN_BITS) - mfn; 93 } 94 95 rate = parent_rate * 2; 96 rate /= pd + 1; 97 98 ull = (unsigned long long)rate * mfn_abs; 99 100 do_div(ull, mfd + 1); 101 102 if (mfn_is_negative(pll, mfn)) 103 ull = (rate * mfi) - ull; 104 else 105 ull = (rate * mfi) + ull; 106 107 return ull; 108 } 109 110 static const struct clk_ops clk_pllv1_ops = { 111 .recalc_rate = clk_pllv1_recalc_rate, 112 }; 113 114 struct clk_hw *imx_clk_hw_pllv1(enum imx_pllv1_type type, const char *name, 115 const char *parent, void __iomem *base) 116 { 117 struct clk_pllv1 *pll; 118 struct clk_hw *hw; 119 struct clk_init_data init; 120 int ret; 121 122 pll = kmalloc(sizeof(*pll), GFP_KERNEL); 123 if (!pll) 124 return ERR_PTR(-ENOMEM); 125 126 pll->base = base; 127 pll->type = type; 128 129 init.name = name; 130 init.ops = &clk_pllv1_ops; 131 init.flags = 0; 132 init.parent_names = &parent; 133 init.num_parents = 1; 134 135 pll->hw.init = &init; 136 hw = &pll->hw; 137 138 ret = clk_hw_register(NULL, hw); 139 if (ret) { 140 kfree(pll); 141 return ERR_PTR(ret); 142 } 143 144 return hw; 145 } 146