xref: /openbmc/linux/drivers/clk/imx/clk-pllv2.c (revision 0f4630f3)
1 #include <linux/kernel.h>
2 #include <linux/clk.h>
3 #include <linux/io.h>
4 #include <linux/errno.h>
5 #include <linux/delay.h>
6 #include <linux/slab.h>
7 #include <linux/err.h>
8 
9 #include <asm/div64.h>
10 
11 #include "clk.h"
12 
13 #define to_clk_pllv2(clk) (container_of(clk, struct clk_pllv2, clk))
14 
15 /* PLL Register Offsets */
16 #define MXC_PLL_DP_CTL			0x00
17 #define MXC_PLL_DP_CONFIG		0x04
18 #define MXC_PLL_DP_OP			0x08
19 #define MXC_PLL_DP_MFD			0x0C
20 #define MXC_PLL_DP_MFN			0x10
21 #define MXC_PLL_DP_MFNMINUS		0x14
22 #define MXC_PLL_DP_MFNPLUS		0x18
23 #define MXC_PLL_DP_HFS_OP		0x1C
24 #define MXC_PLL_DP_HFS_MFD		0x20
25 #define MXC_PLL_DP_HFS_MFN		0x24
26 #define MXC_PLL_DP_MFN_TOGC		0x28
27 #define MXC_PLL_DP_DESTAT		0x2c
28 
29 /* PLL Register Bit definitions */
30 #define MXC_PLL_DP_CTL_MUL_CTRL		0x2000
31 #define MXC_PLL_DP_CTL_DPDCK0_2_EN	0x1000
32 #define MXC_PLL_DP_CTL_DPDCK0_2_OFFSET	12
33 #define MXC_PLL_DP_CTL_ADE		0x800
34 #define MXC_PLL_DP_CTL_REF_CLK_DIV	0x400
35 #define MXC_PLL_DP_CTL_REF_CLK_SEL_MASK	(3 << 8)
36 #define MXC_PLL_DP_CTL_REF_CLK_SEL_OFFSET	8
37 #define MXC_PLL_DP_CTL_HFSM		0x80
38 #define MXC_PLL_DP_CTL_PRE		0x40
39 #define MXC_PLL_DP_CTL_UPEN		0x20
40 #define MXC_PLL_DP_CTL_RST		0x10
41 #define MXC_PLL_DP_CTL_RCP		0x8
42 #define MXC_PLL_DP_CTL_PLM		0x4
43 #define MXC_PLL_DP_CTL_BRM0		0x2
44 #define MXC_PLL_DP_CTL_LRF		0x1
45 
46 #define MXC_PLL_DP_CONFIG_BIST		0x8
47 #define MXC_PLL_DP_CONFIG_SJC_CE	0x4
48 #define MXC_PLL_DP_CONFIG_AREN		0x2
49 #define MXC_PLL_DP_CONFIG_LDREQ		0x1
50 
51 #define MXC_PLL_DP_OP_MFI_OFFSET	4
52 #define MXC_PLL_DP_OP_MFI_MASK		(0xF << 4)
53 #define MXC_PLL_DP_OP_PDF_OFFSET	0
54 #define MXC_PLL_DP_OP_PDF_MASK		0xF
55 
56 #define MXC_PLL_DP_MFD_OFFSET		0
57 #define MXC_PLL_DP_MFD_MASK		0x07FFFFFF
58 
59 #define MXC_PLL_DP_MFN_OFFSET		0x0
60 #define MXC_PLL_DP_MFN_MASK		0x07FFFFFF
61 
62 #define MXC_PLL_DP_MFN_TOGC_TOG_DIS	(1 << 17)
63 #define MXC_PLL_DP_MFN_TOGC_TOG_EN	(1 << 16)
64 #define MXC_PLL_DP_MFN_TOGC_CNT_OFFSET	0x0
65 #define MXC_PLL_DP_MFN_TOGC_CNT_MASK	0xFFFF
66 
67 #define MXC_PLL_DP_DESTAT_TOG_SEL	(1 << 31)
68 #define MXC_PLL_DP_DESTAT_MFN		0x07FFFFFF
69 
70 #define MAX_DPLL_WAIT_TRIES	1000 /* 1000 * udelay(1) = 1ms */
71 
72 struct clk_pllv2 {
73 	struct clk_hw	hw;
74 	void __iomem	*base;
75 };
76 
77 static unsigned long __clk_pllv2_recalc_rate(unsigned long parent_rate,
78 		u32 dp_ctl, u32 dp_op, u32 dp_mfd, u32 dp_mfn)
79 {
80 	long mfi, mfn, mfd, pdf, ref_clk;
81 	unsigned long dbl;
82 	u64 temp;
83 
84 	dbl = dp_ctl & MXC_PLL_DP_CTL_DPDCK0_2_EN;
85 
86 	pdf = dp_op & MXC_PLL_DP_OP_PDF_MASK;
87 	mfi = (dp_op & MXC_PLL_DP_OP_MFI_MASK) >> MXC_PLL_DP_OP_MFI_OFFSET;
88 	mfi = (mfi <= 5) ? 5 : mfi;
89 	mfd = dp_mfd & MXC_PLL_DP_MFD_MASK;
90 	mfn = dp_mfn & MXC_PLL_DP_MFN_MASK;
91 	mfn = sign_extend32(mfn, 26);
92 
93 	ref_clk = 2 * parent_rate;
94 	if (dbl != 0)
95 		ref_clk *= 2;
96 
97 	ref_clk /= (pdf + 1);
98 	temp = (u64) ref_clk * abs(mfn);
99 	do_div(temp, mfd + 1);
100 	if (mfn < 0)
101 		temp = (ref_clk * mfi) - temp;
102 	else
103 		temp = (ref_clk * mfi) + temp;
104 
105 	return temp;
106 }
107 
108 static unsigned long clk_pllv2_recalc_rate(struct clk_hw *hw,
109 		unsigned long parent_rate)
110 {
111 	u32 dp_op, dp_mfd, dp_mfn, dp_ctl;
112 	void __iomem *pllbase;
113 	struct clk_pllv2 *pll = to_clk_pllv2(hw);
114 
115 	pllbase = pll->base;
116 
117 	dp_ctl = __raw_readl(pllbase + MXC_PLL_DP_CTL);
118 	dp_op = __raw_readl(pllbase + MXC_PLL_DP_OP);
119 	dp_mfd = __raw_readl(pllbase + MXC_PLL_DP_MFD);
120 	dp_mfn = __raw_readl(pllbase + MXC_PLL_DP_MFN);
121 
122 	return __clk_pllv2_recalc_rate(parent_rate, dp_ctl, dp_op, dp_mfd, dp_mfn);
123 }
124 
125 static int __clk_pllv2_set_rate(unsigned long rate, unsigned long parent_rate,
126 		u32 *dp_op, u32 *dp_mfd, u32 *dp_mfn)
127 {
128 	u32 reg;
129 	long mfi, pdf, mfn, mfd = 999999;
130 	u64 temp64;
131 	unsigned long quad_parent_rate;
132 
133 	quad_parent_rate = 4 * parent_rate;
134 	pdf = mfi = -1;
135 	while (++pdf < 16 && mfi < 5)
136 		mfi = rate * (pdf+1) / quad_parent_rate;
137 	if (mfi > 15)
138 		return -EINVAL;
139 	pdf--;
140 
141 	temp64 = rate * (pdf + 1) - quad_parent_rate * mfi;
142 	do_div(temp64, quad_parent_rate / 1000000);
143 	mfn = (long)temp64;
144 
145 	reg = mfi << 4 | pdf;
146 
147 	*dp_op = reg;
148 	*dp_mfd = mfd;
149 	*dp_mfn = mfn;
150 
151 	return 0;
152 }
153 
154 static int clk_pllv2_set_rate(struct clk_hw *hw, unsigned long rate,
155 		unsigned long parent_rate)
156 {
157 	struct clk_pllv2 *pll = to_clk_pllv2(hw);
158 	void __iomem *pllbase;
159 	u32 dp_ctl, dp_op, dp_mfd, dp_mfn;
160 	int ret;
161 
162 	pllbase = pll->base;
163 
164 
165 	ret = __clk_pllv2_set_rate(rate, parent_rate, &dp_op, &dp_mfd, &dp_mfn);
166 	if (ret)
167 		return ret;
168 
169 	dp_ctl = __raw_readl(pllbase + MXC_PLL_DP_CTL);
170 	/* use dpdck0_2 */
171 	__raw_writel(dp_ctl | 0x1000L, pllbase + MXC_PLL_DP_CTL);
172 
173 	__raw_writel(dp_op, pllbase + MXC_PLL_DP_OP);
174 	__raw_writel(dp_mfd, pllbase + MXC_PLL_DP_MFD);
175 	__raw_writel(dp_mfn, pllbase + MXC_PLL_DP_MFN);
176 
177 	return 0;
178 }
179 
180 static long clk_pllv2_round_rate(struct clk_hw *hw, unsigned long rate,
181 		unsigned long *prate)
182 {
183 	u32 dp_op, dp_mfd, dp_mfn;
184 
185 	__clk_pllv2_set_rate(rate, *prate, &dp_op, &dp_mfd, &dp_mfn);
186 	return __clk_pllv2_recalc_rate(*prate, MXC_PLL_DP_CTL_DPDCK0_2_EN,
187 			dp_op, dp_mfd, dp_mfn);
188 }
189 
190 static int clk_pllv2_prepare(struct clk_hw *hw)
191 {
192 	struct clk_pllv2 *pll = to_clk_pllv2(hw);
193 	u32 reg;
194 	void __iomem *pllbase;
195 	int i = 0;
196 
197 	pllbase = pll->base;
198 	reg = __raw_readl(pllbase + MXC_PLL_DP_CTL) | MXC_PLL_DP_CTL_UPEN;
199 	__raw_writel(reg, pllbase + MXC_PLL_DP_CTL);
200 
201 	/* Wait for lock */
202 	do {
203 		reg = __raw_readl(pllbase + MXC_PLL_DP_CTL);
204 		if (reg & MXC_PLL_DP_CTL_LRF)
205 			break;
206 
207 		udelay(1);
208 	} while (++i < MAX_DPLL_WAIT_TRIES);
209 
210 	if (i == MAX_DPLL_WAIT_TRIES) {
211 		pr_err("MX5: pll locking failed\n");
212 		return -EINVAL;
213 	}
214 
215 	return 0;
216 }
217 
218 static void clk_pllv2_unprepare(struct clk_hw *hw)
219 {
220 	struct clk_pllv2 *pll = to_clk_pllv2(hw);
221 	u32 reg;
222 	void __iomem *pllbase;
223 
224 	pllbase = pll->base;
225 	reg = __raw_readl(pllbase + MXC_PLL_DP_CTL) & ~MXC_PLL_DP_CTL_UPEN;
226 	__raw_writel(reg, pllbase + MXC_PLL_DP_CTL);
227 }
228 
229 static struct clk_ops clk_pllv2_ops = {
230 	.prepare = clk_pllv2_prepare,
231 	.unprepare = clk_pllv2_unprepare,
232 	.recalc_rate = clk_pllv2_recalc_rate,
233 	.round_rate = clk_pllv2_round_rate,
234 	.set_rate = clk_pllv2_set_rate,
235 };
236 
237 struct clk *imx_clk_pllv2(const char *name, const char *parent,
238 		void __iomem *base)
239 {
240 	struct clk_pllv2 *pll;
241 	struct clk *clk;
242 	struct clk_init_data init;
243 
244 	pll = kzalloc(sizeof(*pll), GFP_KERNEL);
245 	if (!pll)
246 		return ERR_PTR(-ENOMEM);
247 
248 	pll->base = base;
249 
250 	init.name = name;
251 	init.ops = &clk_pllv2_ops;
252 	init.flags = 0;
253 	init.parent_names = &parent;
254 	init.num_parents = 1;
255 
256 	pll->hw.init = &init;
257 
258 	clk = clk_register(NULL, &pll->hw);
259 	if (IS_ERR(clk))
260 		kfree(pll);
261 
262 	return clk;
263 }
264