target/linux/ipq806x/patches/0166-clk-qcom-Add-support-for-High-Frequency-PLLs-HFPLLs.patch

   1 From 8a51ac2a4e36505e1ff82b0e49fd8b2edd0b7695 Mon Sep 17 00:00:00 2001
   2 From: Stephen Boyd <sboyd@codeaurora.org>
   3 Date: Wed, 18 Jun 2014 14:15:58 -0700
   4 Subject: [PATCH 166/182] clk: qcom: Add support for High-Frequency PLLs
   5  (HFPLLs)
   6
   7 HFPLLs are the main frequency source for Krait CPU clocks. Add
   8 support for changing the rate of these PLLs.
   9
  10 Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
  11 ---
  12  drivers/clk/qcom/Makefile    |    1 +
  13  drivers/clk/qcom/clk-hfpll.c |  260 ++++++++++++++++++++++++++++++++++++++++++
  14  drivers/clk/qcom/clk-hfpll.h |   54 +++++++++
  15  3 files changed, 315 insertions(+)
  16  create mode 100644 drivers/clk/qcom/clk-hfpll.c
  17  create mode 100644 drivers/clk/qcom/clk-hfpll.h
  18
  19 --- a/drivers/clk/qcom/Makefile
  20 +++ b/drivers/clk/qcom/Makefile
  21 @@ -7,6 +7,7 @@ clk-qcom-y += clk-rcg.o
  22  clk-qcom-y += clk-rcg2.o
  23  clk-qcom-y += clk-branch.o
  24  clk-qcom-y += clk-generic.o
  25 +clk-qcom-y += clk-hfpll.o
  26  clk-qcom-y += reset.o
  27
  28  obj-$(CONFIG_IPQ_GCC_806X) += gcc-ipq806x.o
  29 --- /dev/null
  30 +++ b/drivers/clk/qcom/clk-hfpll.c
  31 @@ -0,0 +1,260 @@
  32 +/*
  33 + * Copyright (c) 2013-2014, The Linux Foundation. All rights reserved.
  34 + *
  35 + * This program is free software; you can redistribute it and/or modify
  36 + * it under the terms of the GNU General Public License version 2 and
  37 + * only version 2 as published by the Free Software Foundation.
  38 + *
  39 + * This program is distributed in the hope that it will be useful,
  40 + * but WITHOUT ANY WARRANTY; without even the implied warranty of
  41 + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  42 + * GNU General Public License for more details.
  43 + */
  44 +#include <linux/kernel.h>
  45 +#include <linux/module.h>
  46 +#include <linux/init.h>
  47 +#include <linux/regmap.h>
  48 +#include <linux/delay.h>
  49 +#include <linux/err.h>
  50 +#include <linux/clk-provider.h>
  51 +#include <linux/spinlock.h>
  52 +
  53 +#include "clk-regmap.h"
  54 +#include "clk-hfpll.h"
  55 +
  56 +#define PLL_OUTCTRL    BIT(0)
  57 +#define PLL_BYPASSNL   BIT(1)
  58 +#define PLL_RESET_N    BIT(2)
  59 +
  60 +/* Initialize a HFPLL at a given rate and enable it. */
  61 +static void __clk_hfpll_init_once(struct clk_hw *hw)
  62 +{
  63 +       struct clk_hfpll *h = to_clk_hfpll(hw);
  64 +       struct hfpll_data const *hd = h->d;
  65 +       struct regmap *regmap = h->clkr.regmap;
  66 +
  67 +       if (likely(h->init_done))
  68 +               return;
  69 +
  70 +       /* Configure PLL parameters for integer mode. */
  71 +       if (hd->config_val)
  72 +               regmap_write(regmap, hd->config_reg, hd->config_val);
  73 +       regmap_write(regmap, hd->m_reg, 0);
  74 +       regmap_write(regmap, hd->n_reg, 1);
  75 +
  76 +       if (hd->user_reg) {
  77 +               u32 regval = hd->user_val;
  78 +               unsigned long rate;
  79 +
  80 +               rate = __clk_get_rate(hw->clk);
  81 +
  82 +               /* Pick the right VCO. */
  83 +               if (hd->user_vco_mask && rate > hd->low_vco_max_rate)
  84 +                       regval |= hd->user_vco_mask;
  85 +               regmap_write(regmap, hd->user_reg, regval);
  86 +       }
  87 +
  88 +       if (hd->droop_reg)
  89 +               regmap_write(regmap, hd->droop_reg, hd->droop_val);
  90 +
  91 +       h->init_done = true;
  92 +}
  93 +
  94 +static void __clk_hfpll_enable(struct clk_hw *hw)
  95 +{
  96 +       struct clk_hfpll *h = to_clk_hfpll(hw);
  97 +       struct hfpll_data const *hd = h->d;
  98 +       struct regmap *regmap = h->clkr.regmap;
  99 +       u32 val;
 100 +
 101 +       __clk_hfpll_init_once(hw);
 102 +
 103 +       /* Disable PLL bypass mode. */
 104 +       regmap_update_bits(regmap, hd->mode_reg, PLL_BYPASSNL, PLL_BYPASSNL);
 105 +
 106 +       /*
 107 +        * H/W requires a 5us delay between disabling the bypass and
 108 +        * de-asserting the reset. Delay 10us just to be safe.
 109 +        */
 110 +       mb();
 111 +       udelay(10);
 112 +
 113 +       /* De-assert active-low PLL reset. */
 114 +       regmap_update_bits(regmap, hd->mode_reg, PLL_RESET_N, PLL_RESET_N);
 115 +
 116 +       /* Wait for PLL to lock. */
 117 +       if (hd->status_reg) {
 118 +               do {
 119 +                       regmap_read(regmap, hd->status_reg, &val);
 120 +               } while (!(val & BIT(hd->lock_bit)));
 121 +       } else {
 122 +               mb();
 123 +               udelay(60);
 124 +       }
 125 +
 126 +       /* Enable PLL output. */
 127 +       regmap_update_bits(regmap, hd->mode_reg, PLL_OUTCTRL, PLL_OUTCTRL);
 128 +
 129 +       /* Make sure the enable is done before returning. */
 130 +       mb();
 131 +}
 132 +
 133 +/* Enable an already-configured HFPLL. */
 134 +static int clk_hfpll_enable(struct clk_hw *hw)
 135 +{
 136 +       unsigned long flags;
 137 +       struct clk_hfpll *h = to_clk_hfpll(hw);
 138 +       struct hfpll_data const *hd = h->d;
 139 +       struct regmap *regmap = h->clkr.regmap;
 140 +       u32 mode;
 141 +
 142 +       spin_lock_irqsave(&h->lock, flags);
 143 +       regmap_read(regmap, hd->mode_reg, &mode);
 144 +       if (!(mode & (PLL_BYPASSNL | PLL_RESET_N | PLL_OUTCTRL)))
 145 +               __clk_hfpll_enable(hw);
 146 +       spin_unlock_irqrestore(&h->lock, flags);
 147 +
 148 +       return 0;
 149 +}
 150 +
 151 +static void __clk_hfpll_disable(struct clk_hw *hw)
 152 +{
 153 +       struct clk_hfpll *h = to_clk_hfpll(hw);
 154 +       struct hfpll_data const *hd = h->d;
 155 +       struct regmap *regmap = h->clkr.regmap;
 156 +
 157 +       /*
 158 +        * Disable the PLL output, disable test mode, enable the bypass mode,
 159 +        * and assert the reset.
 160 +        */
 161 +       regmap_update_bits(regmap, hd->mode_reg,
 162 +                       PLL_BYPASSNL | PLL_RESET_N | PLL_OUTCTRL, 0);
 163 +}
 164 +
 165 +static void clk_hfpll_disable(struct clk_hw *hw)
 166 +{
 167 +       struct clk_hfpll *h = to_clk_hfpll(hw);
 168 +       unsigned long flags;
 169 +
 170 +       spin_lock_irqsave(&h->lock, flags);
 171 +       __clk_hfpll_disable(hw);
 172 +       spin_unlock_irqrestore(&h->lock, flags);
 173 +}
 174 +
 175 +static long clk_hfpll_round_rate(struct clk_hw *hw, unsigned long rate,
 176 +                                unsigned long *parent_rate)
 177 +{
 178 +       struct clk_hfpll *h = to_clk_hfpll(hw);
 179 +       struct hfpll_data const *hd = h->d;
 180 +       unsigned long rrate;
 181 +
 182 +       rate = clamp(rate, hd->min_rate, hd->max_rate);
 183 +
 184 +       rrate = DIV_ROUND_UP(rate, *parent_rate) * *parent_rate;
 185 +       if (rrate > hd->max_rate)
 186 +               rrate -= *parent_rate;
 187 +
 188 +       return rrate;
 189 +}
 190 +
 191 +/*
 192 + * For optimization reasons, assumes no downstream clocks are actively using
 193 + * it.
 194 + */
 195 +static int clk_hfpll_set_rate(struct clk_hw *hw, unsigned long rate,
 196 +                             unsigned long parent_rate)
 197 +{
 198 +       struct clk_hfpll *h = to_clk_hfpll(hw);
 199 +       struct hfpll_data const *hd = h->d;
 200 +       struct regmap *regmap = h->clkr.regmap;
 201 +       unsigned long flags;
 202 +       u32 l_val, val;
 203 +       bool enabled;
 204 +
 205 +       l_val = rate / parent_rate;
 206 +
 207 +       spin_lock_irqsave(&h->lock, flags);
 208 +
 209 +       enabled = __clk_is_enabled(hw->clk);
 210 +       if (enabled)
 211 +               __clk_hfpll_disable(hw);
 212 +
 213 +       /* Pick the right VCO. */
 214 +       if (hd->user_reg && hd->user_vco_mask) {
 215 +               regmap_read(regmap, hd->user_reg, &val);
 216 +               if (rate <= hd->low_vco_max_rate)
 217 +                       val &= ~hd->user_vco_mask;
 218 +               else
 219 +                       val |= hd->user_vco_mask;
 220 +               regmap_write(regmap, hd->user_reg, val);
 221 +       }
 222 +
 223 +       regmap_write(regmap, hd->l_reg, l_val);
 224 +
 225 +       if (enabled)
 226 +               __clk_hfpll_enable(hw);
 227 +
 228 +       spin_unlock_irqrestore(&h->lock, flags);
 229 +
 230 +       return 0;
 231 +}
 232 +
 233 +static unsigned long clk_hfpll_recalc_rate(struct clk_hw *hw,
 234 +                                          unsigned long parent_rate)
 235 +{
 236 +       struct clk_hfpll *h = to_clk_hfpll(hw);
 237 +       struct hfpll_data const *hd = h->d;
 238 +       struct regmap *regmap = h->clkr.regmap;
 239 +       u32 l_val;
 240 +
 241 +       regmap_read(regmap, hd->l_reg, &l_val);
 242 +
 243 +       return l_val * parent_rate;
 244 +}
 245 +
 246 +static void clk_hfpll_init(struct clk_hw *hw)
 247 +{
 248 +       struct clk_hfpll *h = to_clk_hfpll(hw);
 249 +       struct hfpll_data const *hd = h->d;
 250 +       struct regmap *regmap = h->clkr.regmap;
 251 +       u32 mode, status;
 252 +
 253 +       regmap_read(regmap, hd->mode_reg, &mode);
 254 +       if (mode != (PLL_BYPASSNL | PLL_RESET_N | PLL_OUTCTRL)) {
 255 +               __clk_hfpll_init_once(hw);
 256 +               return;
 257 +       }
 258 +
 259 +       if (hd->status_reg) {
 260 +               regmap_read(regmap, hd->status_reg, &status);
 261 +               if (!(status & BIT(hd->lock_bit))) {
 262 +                       WARN(1, "HFPLL %s is ON, but not locked!\n",
 263 +                                       __clk_get_name(hw->clk));
 264 +                       clk_hfpll_disable(hw);
 265 +                       __clk_hfpll_init_once(hw);
 266 +               }
 267 +       }
 268 +}
 269 +
 270 +static int hfpll_is_enabled(struct clk_hw *hw)
 271 +{
 272 +       struct clk_hfpll *h = to_clk_hfpll(hw);
 273 +       struct hfpll_data const *hd = h->d;
 274 +       struct regmap *regmap = h->clkr.regmap;
 275 +       u32 mode;
 276 +
 277 +       regmap_read(regmap, hd->mode_reg, &mode);
 278 +       mode &= 0x7;
 279 +       return mode == (PLL_BYPASSNL | PLL_RESET_N | PLL_OUTCTRL);
 280 +}
 281 +
 282 +const struct clk_ops clk_ops_hfpll = {
 283 +       .enable = clk_hfpll_enable,
 284 +       .disable = clk_hfpll_disable,
 285 +       .is_enabled = hfpll_is_enabled,
 286 +       .round_rate = clk_hfpll_round_rate,
 287 +       .set_rate = clk_hfpll_set_rate,
 288 +       .recalc_rate = clk_hfpll_recalc_rate,
 289 +       .init = clk_hfpll_init,
 290 +};
 291 +EXPORT_SYMBOL_GPL(clk_ops_hfpll);
 292 --- /dev/null
 293 +++ b/drivers/clk/qcom/clk-hfpll.h
 294 @@ -0,0 +1,54 @@
 295 +/*
 296 + * Copyright (c) 2013-2014, The Linux Foundation. All rights reserved.
 297 + *
 298 + * This program is free software; you can redistribute it and/or modify
 299 + * it under the terms of the GNU General Public License version 2 and
 300 + * only version 2 as published by the Free Software Foundation.
 301 + *
 302 + * This program is distributed in the hope that it will be useful,
 303 + * but WITHOUT ANY WARRANTY; without even the implied warranty of
 304 + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 305 + * GNU General Public License for more details.
 306 + */
 307 +#ifndef __QCOM_CLK_HFPLL_H__
 308 +#define __QCOM_CLK_HFPLL_H__
 309 +
 310 +#include <linux/clk-provider.h>
 311 +#include <linux/spinlock.h>
 312 +#include "clk-regmap.h"
 313 +
 314 +struct hfpll_data {
 315 +       u32 mode_reg;
 316 +       u32 l_reg;
 317 +       u32 m_reg;
 318 +       u32 n_reg;
 319 +       u32 user_reg;
 320 +       u32 droop_reg;
 321 +       u32 config_reg;
 322 +       u32 status_reg;
 323 +       u8  lock_bit;
 324 +
 325 +       u32 droop_val;
 326 +       u32 config_val;
 327 +       u32 user_val;
 328 +       u32 user_vco_mask;
 329 +       unsigned long low_vco_max_rate;
 330 +
 331 +       unsigned long min_rate;
 332 +       unsigned long max_rate;
 333 +};
 334 +
 335 +struct clk_hfpll {
 336 +       struct hfpll_data const *d;
 337 +       int init_done;
 338 +
 339 +       struct clk_regmap clkr;
 340 +       spinlock_t lock;
 341 +};
 342 +
 343 +#define to_clk_hfpll(_hw) \
 344 +       container_of(to_clk_regmap(_hw), struct clk_hfpll, clkr)
 345 +
 346 +extern const struct clk_ops clk_ops_hfpll;
 347 +
 348 +#endif