xref: /openbmc/linux/drivers/clk/mediatek/clk-fhctl.c (revision 2d99a7ec)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2022 MediaTek Inc.
4  * Author: Edward-JW Yang <edward-jw.yang@mediatek.com>
5  */
6 
7 #include <linux/io.h>
8 #include <linux/iopoll.h>
9 
10 #include "clk-mtk.h"
11 #include "clk-pllfh.h"
12 #include "clk-fhctl.h"
13 
14 #define PERCENT_TO_DDSLMT(dds, percent_m10) \
15 	((((dds) * (percent_m10)) >> 5) / 100)
16 
17 static const struct fhctl_offset fhctl_offset = {
18 	.offset_hp_en = 0x0,
19 	.offset_clk_con = 0x8,
20 	.offset_rst_con = 0xc,
21 	.offset_slope0 = 0x10,
22 	.offset_slope1 = 0x14,
23 	.offset_cfg = 0x0,
24 	.offset_updnlmt = 0x4,
25 	.offset_dds = 0x8,
26 	.offset_dvfs = 0xc,
27 	.offset_mon = 0x10,
28 };
29 
30 const struct fhctl_offset *fhctl_get_offset_table(void)
31 {
32 	return &fhctl_offset;
33 }
34 
35 static void dump_hw(struct mtk_clk_pll *pll, struct fh_pll_regs *regs,
36 		    const struct fh_pll_data *data)
37 {
38 	pr_info("hp_en<%x>,clk_con<%x>,slope0<%x>,slope1<%x>\n",
39 		readl(regs->reg_hp_en), readl(regs->reg_clk_con),
40 		readl(regs->reg_slope0), readl(regs->reg_slope1));
41 	pr_info("cfg<%x>,lmt<%x>,dds<%x>,dvfs<%x>,mon<%x>\n",
42 		readl(regs->reg_cfg), readl(regs->reg_updnlmt),
43 		readl(regs->reg_dds), readl(regs->reg_dvfs),
44 		readl(regs->reg_mon));
45 	pr_info("pcw<%x>\n", readl(pll->pcw_addr));
46 }
47 
48 static int fhctl_set_ssc_regs(struct mtk_clk_pll *pll, struct fh_pll_regs *regs,
49 			      const struct fh_pll_data *data, u32 rate)
50 {
51 	u32 updnlmt_val, r;
52 
53 	writel((readl(regs->reg_cfg) & ~(data->frddsx_en)), regs->reg_cfg);
54 	writel((readl(regs->reg_cfg) & ~(data->sfstrx_en)), regs->reg_cfg);
55 	writel((readl(regs->reg_cfg) & ~(data->fhctlx_en)), regs->reg_cfg);
56 
57 	if (rate > 0) {
58 		/* Set the relative parameter registers (dt/df/upbnd/downbnd) */
59 		r = readl(regs->reg_cfg);
60 		r &= ~(data->msk_frddsx_dys);
61 		r |= (data->df_val << (ffs(data->msk_frddsx_dys) - 1));
62 		writel(r, regs->reg_cfg);
63 
64 		r = readl(regs->reg_cfg);
65 		r &= ~(data->msk_frddsx_dts);
66 		r |= (data->dt_val << (ffs(data->msk_frddsx_dts) - 1));
67 		writel(r, regs->reg_cfg);
68 
69 		writel((readl(pll->pcw_addr) & data->dds_mask) | data->tgl_org,
70 			regs->reg_dds);
71 
72 		/* Calculate UPDNLMT */
73 		updnlmt_val = PERCENT_TO_DDSLMT((readl(regs->reg_dds) &
74 						 data->dds_mask), rate) <<
75 						 data->updnlmt_shft;
76 
77 		writel(updnlmt_val, regs->reg_updnlmt);
78 		writel(readl(regs->reg_hp_en) | BIT(data->fh_id),
79 		       regs->reg_hp_en);
80 		/* Enable SSC */
81 		writel(readl(regs->reg_cfg) | data->frddsx_en, regs->reg_cfg);
82 		/* Enable Hopping control */
83 		writel(readl(regs->reg_cfg) | data->fhctlx_en, regs->reg_cfg);
84 
85 	} else {
86 		/* Switch to APMIXEDSYS control */
87 		writel(readl(regs->reg_hp_en) & ~BIT(data->fh_id),
88 		       regs->reg_hp_en);
89 		/* Wait for DDS to be stable */
90 		udelay(30);
91 	}
92 
93 	return 0;
94 }
95 
96 static int hopping_hw_flow(struct mtk_clk_pll *pll, struct fh_pll_regs *regs,
97 			   const struct fh_pll_data *data,
98 			   struct fh_pll_state *state, unsigned int new_dds)
99 {
100 	u32 dds_mask = data->dds_mask;
101 	u32 mon_dds = 0;
102 	u32 con_pcw_tmp;
103 	int ret;
104 
105 	if (state->ssc_rate)
106 		fhctl_set_ssc_regs(pll, regs, data, 0);
107 
108 	writel((readl(pll->pcw_addr) & dds_mask) | data->tgl_org,
109 		regs->reg_dds);
110 
111 	writel(readl(regs->reg_cfg) | data->sfstrx_en, regs->reg_cfg);
112 	writel(readl(regs->reg_cfg) | data->fhctlx_en, regs->reg_cfg);
113 	writel(data->slope0_value, regs->reg_slope0);
114 	writel(data->slope1_value, regs->reg_slope1);
115 
116 	writel(readl(regs->reg_hp_en) | BIT(data->fh_id), regs->reg_hp_en);
117 	writel((new_dds) | (data->dvfs_tri), regs->reg_dvfs);
118 
119 	/* Wait 1000 us until DDS stable */
120 	ret = readl_poll_timeout_atomic(regs->reg_mon, mon_dds,
121 				       (mon_dds & dds_mask) == new_dds,
122 					10, 1000);
123 	if (ret) {
124 		pr_warn("%s: FHCTL hopping timeout\n", pll->data->name);
125 		dump_hw(pll, regs, data);
126 	}
127 
128 	con_pcw_tmp = readl(pll->pcw_addr) & (~dds_mask);
129 	con_pcw_tmp = (con_pcw_tmp | (readl(regs->reg_mon) & dds_mask) |
130 		       data->pcwchg);
131 
132 	writel(con_pcw_tmp, pll->pcw_addr);
133 	writel(readl(regs->reg_hp_en) & ~BIT(data->fh_id), regs->reg_hp_en);
134 
135 	if (state->ssc_rate)
136 		fhctl_set_ssc_regs(pll, regs, data, state->ssc_rate);
137 
138 	return ret;
139 }
140 
141 static unsigned int __get_postdiv(struct mtk_clk_pll *pll)
142 {
143 	unsigned int regval;
144 
145 	regval = readl(pll->pd_addr) >> pll->data->pd_shift;
146 	regval &= POSTDIV_MASK;
147 
148 	return BIT(regval);
149 }
150 
151 static void __set_postdiv(struct mtk_clk_pll *pll, unsigned int postdiv)
152 {
153 	unsigned int regval;
154 
155 	regval = readl(pll->pd_addr);
156 	regval &= ~(POSTDIV_MASK << pll->data->pd_shift);
157 	regval |= (ffs(postdiv) - 1) << pll->data->pd_shift;
158 	writel(regval, pll->pd_addr);
159 }
160 
161 static int fhctl_hopping(struct mtk_fh *fh, unsigned int new_dds,
162 			 unsigned int postdiv)
163 {
164 	const struct fh_pll_data *data = &fh->pllfh_data->data;
165 	struct fh_pll_state *state = &fh->pllfh_data->state;
166 	struct fh_pll_regs *regs = &fh->regs;
167 	struct mtk_clk_pll *pll = &fh->clk_pll;
168 	spinlock_t *lock = fh->lock;
169 	unsigned int pll_postdiv;
170 	unsigned long flags = 0;
171 	int ret;
172 
173 	if (postdiv) {
174 		pll_postdiv = __get_postdiv(pll);
175 
176 		if (postdiv > pll_postdiv)
177 			__set_postdiv(pll, postdiv);
178 	}
179 
180 	spin_lock_irqsave(lock, flags);
181 
182 	ret = hopping_hw_flow(pll, regs, data, state, new_dds);
183 
184 	spin_unlock_irqrestore(lock, flags);
185 
186 	if (postdiv && postdiv < pll_postdiv)
187 		__set_postdiv(pll, postdiv);
188 
189 	return ret;
190 }
191 
192 static int fhctl_ssc_enable(struct mtk_fh *fh, u32 rate)
193 {
194 	const struct fh_pll_data *data = &fh->pllfh_data->data;
195 	struct fh_pll_state *state = &fh->pllfh_data->state;
196 	struct fh_pll_regs *regs = &fh->regs;
197 	struct mtk_clk_pll *pll = &fh->clk_pll;
198 	spinlock_t *lock = fh->lock;
199 	unsigned long flags = 0;
200 
201 	spin_lock_irqsave(lock, flags);
202 
203 	fhctl_set_ssc_regs(pll, regs, data, rate);
204 	state->ssc_rate = rate;
205 
206 	spin_unlock_irqrestore(lock, flags);
207 
208 	return 0;
209 }
210 
211 static const struct fh_operation fhctl_ops = {
212 	.hopping = fhctl_hopping,
213 	.ssc_enable = fhctl_ssc_enable,
214 };
215 
216 const struct fh_operation *fhctl_get_ops(void)
217 {
218 	return &fhctl_ops;
219 }
220 
221 void fhctl_hw_init(struct mtk_fh *fh)
222 {
223 	const struct fh_pll_data data = fh->pllfh_data->data;
224 	struct fh_pll_state state = fh->pllfh_data->state;
225 	struct fh_pll_regs regs = fh->regs;
226 	u32 val;
227 
228 	/* initial hw register */
229 	val = readl(regs.reg_clk_con) | BIT(data.fh_id);
230 	writel(val, regs.reg_clk_con);
231 
232 	val = readl(regs.reg_rst_con) & ~BIT(data.fh_id);
233 	writel(val, regs.reg_rst_con);
234 	val = readl(regs.reg_rst_con) | BIT(data.fh_id);
235 	writel(val, regs.reg_rst_con);
236 
237 	writel(0x0, regs.reg_cfg);
238 	writel(0x0, regs.reg_updnlmt);
239 	writel(0x0, regs.reg_dds);
240 
241 	/* enable ssc if needed */
242 	if (state.ssc_rate)
243 		fh->ops->ssc_enable(fh, state.ssc_rate);
244 }
245