xref: /openbmc/linux/drivers/clk/imx/clk-pllv2.c (revision e3b9f1e8)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/kernel.h>
3 #include <linux/clk.h>
4 #include <linux/io.h>
5 #include <linux/errno.h>
6 #include <linux/delay.h>
7 #include <linux/slab.h>
8 #include <linux/err.h>
9 
10 #include <asm/div64.h>
11 
12 #include "clk.h"
13 
14 #define to_clk_pllv2(clk) (container_of(clk, struct clk_pllv2, clk))
15 
16 /* PLL Register Offsets */
17 #define MXC_PLL_DP_CTL			0x00
18 #define MXC_PLL_DP_CONFIG		0x04
19 #define MXC_PLL_DP_OP			0x08
20 #define MXC_PLL_DP_MFD			0x0C
21 #define MXC_PLL_DP_MFN			0x10
22 #define MXC_PLL_DP_MFNMINUS		0x14
23 #define MXC_PLL_DP_MFNPLUS		0x18
24 #define MXC_PLL_DP_HFS_OP		0x1C
25 #define MXC_PLL_DP_HFS_MFD		0x20
26 #define MXC_PLL_DP_HFS_MFN		0x24
27 #define MXC_PLL_DP_MFN_TOGC		0x28
28 #define MXC_PLL_DP_DESTAT		0x2c
29 
30 /* PLL Register Bit definitions */
31 #define MXC_PLL_DP_CTL_MUL_CTRL		0x2000
32 #define MXC_PLL_DP_CTL_DPDCK0_2_EN	0x1000
33 #define MXC_PLL_DP_CTL_DPDCK0_2_OFFSET	12
34 #define MXC_PLL_DP_CTL_ADE		0x800
35 #define MXC_PLL_DP_CTL_REF_CLK_DIV	0x400
36 #define MXC_PLL_DP_CTL_REF_CLK_SEL_MASK	(3 << 8)
37 #define MXC_PLL_DP_CTL_REF_CLK_SEL_OFFSET	8
38 #define MXC_PLL_DP_CTL_HFSM		0x80
39 #define MXC_PLL_DP_CTL_PRE		0x40
40 #define MXC_PLL_DP_CTL_UPEN		0x20
41 #define MXC_PLL_DP_CTL_RST		0x10
42 #define MXC_PLL_DP_CTL_RCP		0x8
43 #define MXC_PLL_DP_CTL_PLM		0x4
44 #define MXC_PLL_DP_CTL_BRM0		0x2
45 #define MXC_PLL_DP_CTL_LRF		0x1
46 
47 #define MXC_PLL_DP_CONFIG_BIST		0x8
48 #define MXC_PLL_DP_CONFIG_SJC_CE	0x4
49 #define MXC_PLL_DP_CONFIG_AREN		0x2
50 #define MXC_PLL_DP_CONFIG_LDREQ		0x1
51 
52 #define MXC_PLL_DP_OP_MFI_OFFSET	4
53 #define MXC_PLL_DP_OP_MFI_MASK		(0xF << 4)
54 #define MXC_PLL_DP_OP_PDF_OFFSET	0
55 #define MXC_PLL_DP_OP_PDF_MASK		0xF
56 
57 #define MXC_PLL_DP_MFD_OFFSET		0
58 #define MXC_PLL_DP_MFD_MASK		0x07FFFFFF
59 
60 #define MXC_PLL_DP_MFN_OFFSET		0x0
61 #define MXC_PLL_DP_MFN_MASK		0x07FFFFFF
62 
63 #define MXC_PLL_DP_MFN_TOGC_TOG_DIS	(1 << 17)
64 #define MXC_PLL_DP_MFN_TOGC_TOG_EN	(1 << 16)
65 #define MXC_PLL_DP_MFN_TOGC_CNT_OFFSET	0x0
66 #define MXC_PLL_DP_MFN_TOGC_CNT_MASK	0xFFFF
67 
68 #define MXC_PLL_DP_DESTAT_TOG_SEL	(1 << 31)
69 #define MXC_PLL_DP_DESTAT_MFN		0x07FFFFFF
70 
71 #define MAX_DPLL_WAIT_TRIES	1000 /* 1000 * udelay(1) = 1ms */
72 
73 struct clk_pllv2 {
74 	struct clk_hw	hw;
75 	void __iomem	*base;
76 };
77 
78 static unsigned long __clk_pllv2_recalc_rate(unsigned long parent_rate,
79 		u32 dp_ctl, u32 dp_op, u32 dp_mfd, u32 dp_mfn)
80 {
81 	long mfi, mfn, mfd, pdf, ref_clk;
82 	unsigned long dbl;
83 	u64 temp;
84 
85 	dbl = dp_ctl & MXC_PLL_DP_CTL_DPDCK0_2_EN;
86 
87 	pdf = dp_op & MXC_PLL_DP_OP_PDF_MASK;
88 	mfi = (dp_op & MXC_PLL_DP_OP_MFI_MASK) >> MXC_PLL_DP_OP_MFI_OFFSET;
89 	mfi = (mfi <= 5) ? 5 : mfi;
90 	mfd = dp_mfd & MXC_PLL_DP_MFD_MASK;
91 	mfn = dp_mfn & MXC_PLL_DP_MFN_MASK;
92 	mfn = sign_extend32(mfn, 26);
93 
94 	ref_clk = 2 * parent_rate;
95 	if (dbl != 0)
96 		ref_clk *= 2;
97 
98 	ref_clk /= (pdf + 1);
99 	temp = (u64) ref_clk * abs(mfn);
100 	do_div(temp, mfd + 1);
101 	if (mfn < 0)
102 		temp = (ref_clk * mfi) - temp;
103 	else
104 		temp = (ref_clk * mfi) + temp;
105 
106 	return temp;
107 }
108 
109 static unsigned long clk_pllv2_recalc_rate(struct clk_hw *hw,
110 		unsigned long parent_rate)
111 {
112 	u32 dp_op, dp_mfd, dp_mfn, dp_ctl;
113 	void __iomem *pllbase;
114 	struct clk_pllv2 *pll = to_clk_pllv2(hw);
115 
116 	pllbase = pll->base;
117 
118 	dp_ctl = __raw_readl(pllbase + MXC_PLL_DP_CTL);
119 	dp_op = __raw_readl(pllbase + MXC_PLL_DP_OP);
120 	dp_mfd = __raw_readl(pllbase + MXC_PLL_DP_MFD);
121 	dp_mfn = __raw_readl(pllbase + MXC_PLL_DP_MFN);
122 
123 	return __clk_pllv2_recalc_rate(parent_rate, dp_ctl, dp_op, dp_mfd, dp_mfn);
124 }
125 
126 static int __clk_pllv2_set_rate(unsigned long rate, unsigned long parent_rate,
127 		u32 *dp_op, u32 *dp_mfd, u32 *dp_mfn)
128 {
129 	u32 reg;
130 	long mfi, pdf, mfn, mfd = 999999;
131 	u64 temp64;
132 	unsigned long quad_parent_rate;
133 
134 	quad_parent_rate = 4 * parent_rate;
135 	pdf = mfi = -1;
136 	while (++pdf < 16 && mfi < 5)
137 		mfi = rate * (pdf+1) / quad_parent_rate;
138 	if (mfi > 15)
139 		return -EINVAL;
140 	pdf--;
141 
142 	temp64 = rate * (pdf + 1) - quad_parent_rate * mfi;
143 	do_div(temp64, quad_parent_rate / 1000000);
144 	mfn = (long)temp64;
145 
146 	reg = mfi << 4 | pdf;
147 
148 	*dp_op = reg;
149 	*dp_mfd = mfd;
150 	*dp_mfn = mfn;
151 
152 	return 0;
153 }
154 
155 static int clk_pllv2_set_rate(struct clk_hw *hw, unsigned long rate,
156 		unsigned long parent_rate)
157 {
158 	struct clk_pllv2 *pll = to_clk_pllv2(hw);
159 	void __iomem *pllbase;
160 	u32 dp_ctl, dp_op, dp_mfd, dp_mfn;
161 	int ret;
162 
163 	pllbase = pll->base;
164 
165 
166 	ret = __clk_pllv2_set_rate(rate, parent_rate, &dp_op, &dp_mfd, &dp_mfn);
167 	if (ret)
168 		return ret;
169 
170 	dp_ctl = __raw_readl(pllbase + MXC_PLL_DP_CTL);
171 	/* use dpdck0_2 */
172 	__raw_writel(dp_ctl | 0x1000L, pllbase + MXC_PLL_DP_CTL);
173 
174 	__raw_writel(dp_op, pllbase + MXC_PLL_DP_OP);
175 	__raw_writel(dp_mfd, pllbase + MXC_PLL_DP_MFD);
176 	__raw_writel(dp_mfn, pllbase + MXC_PLL_DP_MFN);
177 
178 	return 0;
179 }
180 
181 static long clk_pllv2_round_rate(struct clk_hw *hw, unsigned long rate,
182 		unsigned long *prate)
183 {
184 	u32 dp_op, dp_mfd, dp_mfn;
185 
186 	__clk_pllv2_set_rate(rate, *prate, &dp_op, &dp_mfd, &dp_mfn);
187 	return __clk_pllv2_recalc_rate(*prate, MXC_PLL_DP_CTL_DPDCK0_2_EN,
188 			dp_op, dp_mfd, dp_mfn);
189 }
190 
191 static int clk_pllv2_prepare(struct clk_hw *hw)
192 {
193 	struct clk_pllv2 *pll = to_clk_pllv2(hw);
194 	u32 reg;
195 	void __iomem *pllbase;
196 	int i = 0;
197 
198 	pllbase = pll->base;
199 	reg = __raw_readl(pllbase + MXC_PLL_DP_CTL) | MXC_PLL_DP_CTL_UPEN;
200 	__raw_writel(reg, pllbase + MXC_PLL_DP_CTL);
201 
202 	/* Wait for lock */
203 	do {
204 		reg = __raw_readl(pllbase + MXC_PLL_DP_CTL);
205 		if (reg & MXC_PLL_DP_CTL_LRF)
206 			break;
207 
208 		udelay(1);
209 	} while (++i < MAX_DPLL_WAIT_TRIES);
210 
211 	if (i == MAX_DPLL_WAIT_TRIES) {
212 		pr_err("MX5: pll locking failed\n");
213 		return -EINVAL;
214 	}
215 
216 	return 0;
217 }
218 
219 static void clk_pllv2_unprepare(struct clk_hw *hw)
220 {
221 	struct clk_pllv2 *pll = to_clk_pllv2(hw);
222 	u32 reg;
223 	void __iomem *pllbase;
224 
225 	pllbase = pll->base;
226 	reg = __raw_readl(pllbase + MXC_PLL_DP_CTL) & ~MXC_PLL_DP_CTL_UPEN;
227 	__raw_writel(reg, pllbase + MXC_PLL_DP_CTL);
228 }
229 
230 static const struct clk_ops clk_pllv2_ops = {
231 	.prepare = clk_pllv2_prepare,
232 	.unprepare = clk_pllv2_unprepare,
233 	.recalc_rate = clk_pllv2_recalc_rate,
234 	.round_rate = clk_pllv2_round_rate,
235 	.set_rate = clk_pllv2_set_rate,
236 };
237 
238 struct clk *imx_clk_pllv2(const char *name, const char *parent,
239 		void __iomem *base)
240 {
241 	struct clk_pllv2 *pll;
242 	struct clk *clk;
243 	struct clk_init_data init;
244 
245 	pll = kzalloc(sizeof(*pll), GFP_KERNEL);
246 	if (!pll)
247 		return ERR_PTR(-ENOMEM);
248 
249 	pll->base = base;
250 
251 	init.name = name;
252 	init.ops = &clk_pllv2_ops;
253 	init.flags = 0;
254 	init.parent_names = &parent;
255 	init.num_parents = 1;
256 
257 	pll->hw.init = &init;
258 
259 	clk = clk_register(NULL, &pll->hw);
260 	if (IS_ERR(clk))
261 		kfree(pll);
262 
263 	return clk;
264 }
265