1 /* 2 * Marvell PXA family clocks 3 * 4 * Copyright (C) 2014 Robert Jarzmik 5 * 6 * Common clock code for PXA clocks ("CKEN" type clocks + DT) 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License as published by 10 * the Free Software Foundation; version 2 of the License. 11 * 12 */ 13 #include <linux/clk.h> 14 #include <linux/clk-provider.h> 15 #include <linux/clkdev.h> 16 #include <linux/of.h> 17 18 #include <dt-bindings/clock/pxa-clock.h> 19 #include "clk-pxa.h" 20 21 #define KHz 1000 22 #define MHz (1000 * 1000) 23 24 #define MDREFR_K0DB4 (1 << 29) /* SDCLK0 Divide by 4 Control/Status */ 25 #define MDREFR_K2FREE (1 << 25) /* SDRAM Free-Running Control */ 26 #define MDREFR_K1FREE (1 << 24) /* SDRAM Free-Running Control */ 27 #define MDREFR_K0FREE (1 << 23) /* SDRAM Free-Running Control */ 28 #define MDREFR_SLFRSH (1 << 22) /* SDRAM Self-Refresh Control/Status */ 29 #define MDREFR_APD (1 << 20) /* SDRAM/SSRAM Auto-Power-Down Enable */ 30 #define MDREFR_K2DB2 (1 << 19) /* SDCLK2 Divide by 2 Control/Status */ 31 #define MDREFR_K2RUN (1 << 18) /* SDCLK2 Run Control/Status */ 32 #define MDREFR_K1DB2 (1 << 17) /* SDCLK1 Divide by 2 Control/Status */ 33 #define MDREFR_K1RUN (1 << 16) /* SDCLK1 Run Control/Status */ 34 #define MDREFR_E1PIN (1 << 15) /* SDCKE1 Level Control/Status */ 35 #define MDREFR_K0DB2 (1 << 14) /* SDCLK0 Divide by 2 Control/Status */ 36 #define MDREFR_K0RUN (1 << 13) /* SDCLK0 Run Control/Status */ 37 #define MDREFR_E0PIN (1 << 12) /* SDCKE0 Level Control/Status */ 38 #define MDREFR_DB2_MASK (MDREFR_K2DB2 | MDREFR_K1DB2) 39 #define MDREFR_DRI_MASK 0xFFF 40 41 static DEFINE_SPINLOCK(pxa_clk_lock); 42 43 static struct clk *pxa_clocks[CLK_MAX]; 44 static struct clk_onecell_data onecell_data = { 45 .clks = pxa_clocks, 46 .clk_num = CLK_MAX, 47 }; 48 49 struct pxa_clk { 50 struct clk_hw hw; 51 struct clk_fixed_factor lp; 52 struct clk_fixed_factor hp; 53 struct clk_gate gate; 54 bool (*is_in_low_power)(void); 55 }; 56 57 #define to_pxa_clk(_hw) container_of(_hw, struct pxa_clk, hw) 58 59 static unsigned long cken_recalc_rate(struct clk_hw *hw, 60 unsigned long parent_rate) 61 { 62 struct pxa_clk *pclk = to_pxa_clk(hw); 63 struct clk_fixed_factor *fix; 64 65 if (!pclk->is_in_low_power || pclk->is_in_low_power()) 66 fix = &pclk->lp; 67 else 68 fix = &pclk->hp; 69 __clk_hw_set_clk(&fix->hw, hw); 70 return clk_fixed_factor_ops.recalc_rate(&fix->hw, parent_rate); 71 } 72 73 static const struct clk_ops cken_rate_ops = { 74 .recalc_rate = cken_recalc_rate, 75 }; 76 77 static u8 cken_get_parent(struct clk_hw *hw) 78 { 79 struct pxa_clk *pclk = to_pxa_clk(hw); 80 81 if (!pclk->is_in_low_power) 82 return 0; 83 return pclk->is_in_low_power() ? 0 : 1; 84 } 85 86 static const struct clk_ops cken_mux_ops = { 87 .get_parent = cken_get_parent, 88 .set_parent = dummy_clk_set_parent, 89 }; 90 91 void __init clkdev_pxa_register(int ckid, const char *con_id, 92 const char *dev_id, struct clk *clk) 93 { 94 if (!IS_ERR(clk) && (ckid != CLK_NONE)) 95 pxa_clocks[ckid] = clk; 96 if (!IS_ERR(clk)) 97 clk_register_clkdev(clk, con_id, dev_id); 98 } 99 100 int __init clk_pxa_cken_init(const struct desc_clk_cken *clks, int nb_clks) 101 { 102 int i; 103 struct pxa_clk *pxa_clk; 104 struct clk *clk; 105 106 for (i = 0; i < nb_clks; i++) { 107 pxa_clk = kzalloc(sizeof(*pxa_clk), GFP_KERNEL); 108 pxa_clk->is_in_low_power = clks[i].is_in_low_power; 109 pxa_clk->lp = clks[i].lp; 110 pxa_clk->hp = clks[i].hp; 111 pxa_clk->gate = clks[i].gate; 112 pxa_clk->gate.lock = &pxa_clk_lock; 113 clk = clk_register_composite(NULL, clks[i].name, 114 clks[i].parent_names, 2, 115 &pxa_clk->hw, &cken_mux_ops, 116 &pxa_clk->hw, &cken_rate_ops, 117 &pxa_clk->gate.hw, &clk_gate_ops, 118 clks[i].flags); 119 clkdev_pxa_register(clks[i].ckid, clks[i].con_id, 120 clks[i].dev_id, clk); 121 } 122 return 0; 123 } 124 125 void __init clk_pxa_dt_common_init(struct device_node *np) 126 { 127 of_clk_add_provider(np, of_clk_src_onecell_get, &onecell_data); 128 } 129 130 void pxa2xx_core_turbo_switch(bool on) 131 { 132 unsigned long flags; 133 unsigned int unused, clkcfg; 134 135 local_irq_save(flags); 136 137 asm("mrc p14, 0, %0, c6, c0, 0" : "=r" (clkcfg)); 138 clkcfg &= ~CLKCFG_TURBO & ~CLKCFG_HALFTURBO; 139 if (on) 140 clkcfg |= CLKCFG_TURBO; 141 clkcfg |= CLKCFG_FCS; 142 143 asm volatile( 144 " b 2f\n" 145 " .align 5\n" 146 "1: mcr p14, 0, %1, c6, c0, 0\n" 147 " b 3f\n" 148 "2: b 1b\n" 149 "3: nop\n" 150 : "=&r" (unused) : "r" (clkcfg)); 151 152 local_irq_restore(flags); 153 } 154 155 void pxa2xx_cpll_change(struct pxa2xx_freq *freq, 156 u32 (*mdrefr_dri)(unsigned int), void __iomem *mdrefr, 157 void __iomem *cccr) 158 { 159 unsigned int clkcfg = freq->clkcfg; 160 unsigned int unused, preset_mdrefr, postset_mdrefr; 161 unsigned long flags; 162 163 local_irq_save(flags); 164 165 /* Calculate the next MDREFR. If we're slowing down the SDRAM clock 166 * we need to preset the smaller DRI before the change. If we're 167 * speeding up we need to set the larger DRI value after the change. 168 */ 169 preset_mdrefr = postset_mdrefr = readl(mdrefr); 170 if ((preset_mdrefr & MDREFR_DRI_MASK) > mdrefr_dri(freq->membus_khz)) { 171 preset_mdrefr = (preset_mdrefr & ~MDREFR_DRI_MASK); 172 preset_mdrefr |= mdrefr_dri(freq->membus_khz); 173 } 174 postset_mdrefr = 175 (postset_mdrefr & ~MDREFR_DRI_MASK) | 176 mdrefr_dri(freq->membus_khz); 177 178 /* If we're dividing the memory clock by two for the SDRAM clock, this 179 * must be set prior to the change. Clearing the divide must be done 180 * after the change. 181 */ 182 if (freq->div2) { 183 preset_mdrefr |= MDREFR_DB2_MASK; 184 postset_mdrefr |= MDREFR_DB2_MASK; 185 } else { 186 postset_mdrefr &= ~MDREFR_DB2_MASK; 187 } 188 189 /* Set new the CCCR and prepare CLKCFG */ 190 writel(freq->cccr, cccr); 191 192 asm volatile( 193 " ldr r4, [%1]\n" 194 " b 2f\n" 195 " .align 5\n" 196 "1: str %3, [%1] /* preset the MDREFR */\n" 197 " mcr p14, 0, %2, c6, c0, 0 /* set CLKCFG[FCS] */\n" 198 " str %4, [%1] /* postset the MDREFR */\n" 199 " b 3f\n" 200 "2: b 1b\n" 201 "3: nop\n" 202 : "=&r" (unused) 203 : "r" (mdrefr), "r" (clkcfg), "r" (preset_mdrefr), 204 "r" (postset_mdrefr) 205 : "r4", "r5"); 206 207 local_irq_restore(flags); 208 } 209 210 int pxa2xx_determine_rate(struct clk_rate_request *req, 211 struct pxa2xx_freq *freqs, int nb_freqs) 212 { 213 int i, closest_below = -1, closest_above = -1; 214 unsigned long rate; 215 216 for (i = 0; i < nb_freqs; i++) { 217 rate = freqs[i].cpll; 218 if (rate == req->rate) 219 break; 220 if (rate < req->min_rate) 221 continue; 222 if (rate > req->max_rate) 223 continue; 224 if (rate <= req->rate) 225 closest_below = i; 226 if ((rate >= req->rate) && (closest_above == -1)) 227 closest_above = i; 228 } 229 230 req->best_parent_hw = NULL; 231 232 if (i < nb_freqs) { 233 rate = req->rate; 234 } else if (closest_below >= 0) { 235 rate = freqs[closest_below].cpll; 236 } else if (closest_above >= 0) { 237 rate = freqs[closest_above].cpll; 238 } else { 239 pr_debug("%s(rate=%lu) no match\n", __func__, req->rate); 240 return -EINVAL; 241 } 242 243 pr_debug("%s(rate=%lu) rate=%lu\n", __func__, req->rate, rate); 244 req->rate = rate; 245 246 return 0; 247 } 248