clk: imx: pllv3: fix potential 'divide by zero' in av_get_rate()
[platform/kernel/u-boot.git] / drivers / clk / imx / clk-pllv3.c
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2019 DENX Software Engineering
4  * Lukasz Majewski, DENX Software Engineering, lukma@denx.de
5  */
6
7 #include <common.h>
8 #include <asm/io.h>
9 #include <div64.h>
10 #include <malloc.h>
11 #include <clk-uclass.h>
12 #include <dm/device.h>
13 #include <dm/uclass.h>
14 #include <clk.h>
15 #include "clk.h"
16
17 #define UBOOT_DM_CLK_IMX_PLLV3_GENERIC  "imx_clk_pllv3_generic"
18 #define UBOOT_DM_CLK_IMX_PLLV3_SYS      "imx_clk_pllv3_sys"
19 #define UBOOT_DM_CLK_IMX_PLLV3_USB      "imx_clk_pllv3_usb"
20 #define UBOOT_DM_CLK_IMX_PLLV3_AV       "imx_clk_pllv3_av"
21
22 #define PLL_NUM_OFFSET          0x10
23 #define PLL_DENOM_OFFSET        0x20
24
25 #define BM_PLL_POWER            (0x1 << 12)
26 #define BM_PLL_LOCK             (0x1 << 31)
27
28 struct clk_pllv3 {
29         struct clk      clk;
30         void __iomem    *base;
31         u32             power_bit;
32         bool            powerup_set;
33         u32             div_mask;
34         u32             div_shift;
35 };
36
37 #define to_clk_pllv3(_clk) container_of(_clk, struct clk_pllv3, clk)
38
39 static ulong clk_pllv3_generic_get_rate(struct clk *clk)
40 {
41         struct clk_pllv3 *pll = to_clk_pllv3(dev_get_clk_ptr(clk->dev));
42         unsigned long parent_rate = clk_get_parent_rate(clk);
43
44         u32 div = (readl(pll->base) >> pll->div_shift) & pll->div_mask;
45
46         return (div == 1) ? parent_rate * 22 : parent_rate * 20;
47 }
48
49 static ulong clk_pllv3_generic_set_rate(struct clk *clk, ulong rate)
50 {
51         struct clk_pllv3 *pll = to_clk_pllv3(clk);
52         unsigned long parent_rate = clk_get_parent_rate(clk);
53         u32 val, div;
54
55         if (rate == parent_rate * 22)
56                 div = 1;
57         else if (rate == parent_rate * 20)
58                 div = 0;
59         else
60                 return -EINVAL;
61
62         val = readl(pll->base);
63         val &= ~(pll->div_mask << pll->div_shift);
64         val |= (div << pll->div_shift);
65         writel(val, pll->base);
66
67         /* Wait for PLL to lock */
68         while (!(readl(pll->base) & BM_PLL_LOCK))
69                 ;
70
71         return 0;
72 }
73
74 static int clk_pllv3_generic_enable(struct clk *clk)
75 {
76         struct clk_pllv3 *pll = to_clk_pllv3(clk);
77         u32 val;
78
79         val = readl(pll->base);
80         if (pll->powerup_set)
81                 val |= pll->power_bit;
82         else
83                 val &= ~pll->power_bit;
84         writel(val, pll->base);
85
86         return 0;
87 }
88
89 static int clk_pllv3_generic_disable(struct clk *clk)
90 {
91         struct clk_pllv3 *pll = to_clk_pllv3(clk);
92         u32 val;
93
94         val = readl(pll->base);
95         if (pll->powerup_set)
96                 val &= ~pll->power_bit;
97         else
98                 val |= pll->power_bit;
99         writel(val, pll->base);
100
101         return 0;
102 }
103
104 static const struct clk_ops clk_pllv3_generic_ops = {
105         .get_rate       = clk_pllv3_generic_get_rate,
106         .enable         = clk_pllv3_generic_enable,
107         .disable        = clk_pllv3_generic_disable,
108         .set_rate       = clk_pllv3_generic_set_rate,
109 };
110
111 static ulong clk_pllv3_sys_get_rate(struct clk *clk)
112 {
113         struct clk_pllv3 *pll = to_clk_pllv3(clk);
114         unsigned long parent_rate = clk_get_parent_rate(clk);
115         u32 div = readl(pll->base) & pll->div_mask;
116
117         return parent_rate * div / 2;
118 }
119
120 static ulong clk_pllv3_sys_set_rate(struct clk *clk, ulong rate)
121 {
122         struct clk_pllv3 *pll = to_clk_pllv3(clk);
123         unsigned long parent_rate = clk_get_parent_rate(clk);
124         unsigned long min_rate;
125         unsigned long max_rate;
126         u32 val, div;
127
128         if (parent_rate == 0)
129                 return -EINVAL;
130
131         min_rate = parent_rate * 54 / 2;
132         max_rate = parent_rate * 108 / 2;
133
134         if (rate < min_rate || rate > max_rate)
135                 return -EINVAL;
136
137         div = rate * 2 / parent_rate;
138         val = readl(pll->base);
139         val &= ~pll->div_mask;
140         val |= div;
141         writel(val, pll->base);
142
143         /* Wait for PLL to lock */
144         while (!(readl(pll->base) & BM_PLL_LOCK))
145                 ;
146
147         return 0;
148 }
149
150 static const struct clk_ops clk_pllv3_sys_ops = {
151         .enable         = clk_pllv3_generic_enable,
152         .disable        = clk_pllv3_generic_disable,
153         .get_rate       = clk_pllv3_sys_get_rate,
154         .set_rate       = clk_pllv3_sys_set_rate,
155 };
156
157 static ulong clk_pllv3_av_get_rate(struct clk *clk)
158 {
159         struct clk_pllv3 *pll = to_clk_pllv3(clk);
160         unsigned long parent_rate = clk_get_parent_rate(clk);
161         u32 mfn = readl(pll->base + PLL_NUM_OFFSET);
162         u32 mfd = readl(pll->base + PLL_DENOM_OFFSET);
163         u32 div = readl(pll->base) & pll->div_mask;
164         u64 temp64 = (u64)parent_rate;
165
166         if (mfd == 0)
167                 return -EIO;
168
169         temp64 *= mfn;
170         do_div(temp64, mfd);
171
172         return parent_rate * div + (unsigned long)temp64;
173 }
174
175 static ulong clk_pllv3_av_set_rate(struct clk *clk, ulong rate)
176 {
177         struct clk_pllv3 *pll = to_clk_pllv3(clk);
178         unsigned long parent_rate = clk_get_parent_rate(clk);
179         unsigned long min_rate = parent_rate * 27;
180         unsigned long max_rate = parent_rate * 54;
181         u32 val, div;
182         u32 mfn, mfd = 1000000;
183         u32 max_mfd = 0x3FFFFFFF;
184         u64 temp64;
185
186         if (rate < min_rate || rate > max_rate)
187                 return -EINVAL;
188
189         if (parent_rate <= max_mfd)
190                 mfd = parent_rate;
191
192         div = rate / parent_rate;
193         temp64 = (u64)(rate - div * parent_rate);
194         temp64 *= mfd;
195         do_div(temp64, parent_rate);
196         mfn = temp64;
197
198         val = readl(pll->base);
199         val &= ~pll->div_mask;
200         val |= div;
201         writel(val, pll->base);
202         writel(mfn, pll->base + PLL_NUM_OFFSET);
203         writel(mfd, pll->base + PLL_DENOM_OFFSET);
204
205         /* Wait for PLL to lock */
206         while (!(readl(pll->base) & BM_PLL_LOCK))
207                 ;
208
209         return 0;
210 }
211
212 static const struct clk_ops clk_pllv3_av_ops = {
213         .enable         = clk_pllv3_generic_enable,
214         .disable        = clk_pllv3_generic_disable,
215         .get_rate       = clk_pllv3_av_get_rate,
216         .set_rate       = clk_pllv3_av_set_rate,
217 };
218
219 struct clk *imx_clk_pllv3(enum imx_pllv3_type type, const char *name,
220                           const char *parent_name, void __iomem *base,
221                           u32 div_mask)
222 {
223         struct clk_pllv3 *pll;
224         struct clk *clk;
225         char *drv_name;
226         int ret;
227
228         pll = kzalloc(sizeof(*pll), GFP_KERNEL);
229         if (!pll)
230                 return ERR_PTR(-ENOMEM);
231
232         pll->power_bit = BM_PLL_POWER;
233
234         switch (type) {
235         case IMX_PLLV3_GENERIC:
236                 drv_name = UBOOT_DM_CLK_IMX_PLLV3_GENERIC;
237                 pll->div_shift = 0;
238                 pll->powerup_set = false;
239                 break;
240         case IMX_PLLV3_SYS:
241                 drv_name = UBOOT_DM_CLK_IMX_PLLV3_SYS;
242                 pll->div_shift = 0;
243                 pll->powerup_set = false;
244                 break;
245         case IMX_PLLV3_USB:
246                 drv_name = UBOOT_DM_CLK_IMX_PLLV3_USB;
247                 pll->div_shift = 1;
248                 pll->powerup_set = true;
249                 break;
250         case IMX_PLLV3_AV:
251                 drv_name = UBOOT_DM_CLK_IMX_PLLV3_AV;
252                 pll->div_shift = 0;
253                 pll->powerup_set = false;
254                 break;
255         default:
256                 kfree(pll);
257                 return ERR_PTR(-ENOTSUPP);
258         }
259
260         pll->base = base;
261         pll->div_mask = div_mask;
262         clk = &pll->clk;
263
264         ret = clk_register(clk, drv_name, name, parent_name);
265         if (ret) {
266                 kfree(pll);
267                 return ERR_PTR(ret);
268         }
269
270         return clk;
271 }
272
273 U_BOOT_DRIVER(clk_pllv3_generic) = {
274         .name   = UBOOT_DM_CLK_IMX_PLLV3_GENERIC,
275         .id     = UCLASS_CLK,
276         .ops    = &clk_pllv3_generic_ops,
277         .flags = DM_FLAG_PRE_RELOC,
278 };
279
280 U_BOOT_DRIVER(clk_pllv3_sys) = {
281         .name   = UBOOT_DM_CLK_IMX_PLLV3_SYS,
282         .id     = UCLASS_CLK,
283         .ops    = &clk_pllv3_sys_ops,
284         .flags = DM_FLAG_PRE_RELOC,
285 };
286
287 U_BOOT_DRIVER(clk_pllv3_usb) = {
288         .name   = UBOOT_DM_CLK_IMX_PLLV3_USB,
289         .id     = UCLASS_CLK,
290         .ops    = &clk_pllv3_generic_ops,
291         .flags = DM_FLAG_PRE_RELOC,
292 };
293
294 U_BOOT_DRIVER(clk_pllv3_av) = {
295         .name   = UBOOT_DM_CLK_IMX_PLLV3_AV,
296         .id     = UCLASS_CLK,
297         .ops    = &clk_pllv3_av_ops,
298         .flags = DM_FLAG_PRE_RELOC,
299 };