linux/drivers/gpu/drm/msm/mdp/mdp4/mdp4_lvds_pll.c
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   1/*
   2 * Copyright (C) 2014 Red Hat
   3 * Author: Rob Clark <robdclark@gmail.com>
   4 *
   5 * This program is free software; you can redistribute it and/or modify it
   6 * under the terms of the GNU General Public License version 2 as published by
   7 * the Free Software Foundation.
   8 *
   9 * This program is distributed in the hope that it will be useful, but WITHOUT
  10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12 * more details.
  13 *
  14 * You should have received a copy of the GNU General Public License along with
  15 * this program.  If not, see <http://www.gnu.org/licenses/>.
  16 */
  17
  18#include <linux/clk.h>
  19#include <linux/clk-provider.h>
  20
  21#include "mdp4_kms.h"
  22
  23struct mdp4_lvds_pll {
  24        struct clk_hw pll_hw;
  25        struct drm_device *dev;
  26        unsigned long pixclk;
  27};
  28#define to_mdp4_lvds_pll(x) container_of(x, struct mdp4_lvds_pll, pll_hw)
  29
  30static struct mdp4_kms *get_kms(struct mdp4_lvds_pll *lvds_pll)
  31{
  32        struct msm_drm_private *priv = lvds_pll->dev->dev_private;
  33        return to_mdp4_kms(to_mdp_kms(priv->kms));
  34}
  35
  36struct pll_rate {
  37        unsigned long rate;
  38        struct {
  39                uint32_t val;
  40                uint32_t reg;
  41        } conf[32];
  42};
  43
  44/* NOTE: keep sorted highest freq to lowest: */
  45static const struct pll_rate freqtbl[] = {
  46        { 72000000, {
  47                { 0x8f, REG_MDP4_LVDS_PHY_PLL_CTRL_1 },
  48                { 0x30, REG_MDP4_LVDS_PHY_PLL_CTRL_2 },
  49                { 0xc6, REG_MDP4_LVDS_PHY_PLL_CTRL_3 },
  50                { 0x10, REG_MDP4_LVDS_PHY_PLL_CTRL_5 },
  51                { 0x07, REG_MDP4_LVDS_PHY_PLL_CTRL_6 },
  52                { 0x62, REG_MDP4_LVDS_PHY_PLL_CTRL_7 },
  53                { 0x41, REG_MDP4_LVDS_PHY_PLL_CTRL_8 },
  54                { 0x0d, REG_MDP4_LVDS_PHY_PLL_CTRL_9 },
  55                { 0, 0 } }
  56        },
  57};
  58
  59static const struct pll_rate *find_rate(unsigned long rate)
  60{
  61        int i;
  62        for (i = 1; i < ARRAY_SIZE(freqtbl); i++)
  63                if (rate > freqtbl[i].rate)
  64                        return &freqtbl[i-1];
  65        return &freqtbl[i-1];
  66}
  67
  68static int mpd4_lvds_pll_enable(struct clk_hw *hw)
  69{
  70        struct mdp4_lvds_pll *lvds_pll = to_mdp4_lvds_pll(hw);
  71        struct mdp4_kms *mdp4_kms = get_kms(lvds_pll);
  72        const struct pll_rate *pll_rate = find_rate(lvds_pll->pixclk);
  73        int i;
  74
  75        DBG("pixclk=%lu (%lu)", lvds_pll->pixclk, pll_rate->rate);
  76
  77        if (WARN_ON(!pll_rate))
  78                return -EINVAL;
  79
  80        mdp4_write(mdp4_kms, REG_MDP4_LCDC_LVDS_PHY_RESET, 0x33);
  81
  82        for (i = 0; pll_rate->conf[i].reg; i++)
  83                mdp4_write(mdp4_kms, pll_rate->conf[i].reg, pll_rate->conf[i].val);
  84
  85        mdp4_write(mdp4_kms, REG_MDP4_LVDS_PHY_PLL_CTRL_0, 0x01);
  86
  87        /* Wait until LVDS PLL is locked and ready */
  88        while (!mdp4_read(mdp4_kms, REG_MDP4_LVDS_PHY_PLL_LOCKED))
  89                cpu_relax();
  90
  91        return 0;
  92}
  93
  94static void mpd4_lvds_pll_disable(struct clk_hw *hw)
  95{
  96        struct mdp4_lvds_pll *lvds_pll = to_mdp4_lvds_pll(hw);
  97        struct mdp4_kms *mdp4_kms = get_kms(lvds_pll);
  98
  99        DBG("");
 100
 101        mdp4_write(mdp4_kms, REG_MDP4_LVDS_PHY_CFG0, 0x0);
 102        mdp4_write(mdp4_kms, REG_MDP4_LVDS_PHY_PLL_CTRL_0, 0x0);
 103}
 104
 105static unsigned long mpd4_lvds_pll_recalc_rate(struct clk_hw *hw,
 106                                unsigned long parent_rate)
 107{
 108        struct mdp4_lvds_pll *lvds_pll = to_mdp4_lvds_pll(hw);
 109        return lvds_pll->pixclk;
 110}
 111
 112static long mpd4_lvds_pll_round_rate(struct clk_hw *hw, unsigned long rate,
 113                unsigned long *parent_rate)
 114{
 115        const struct pll_rate *pll_rate = find_rate(rate);
 116        return pll_rate->rate;
 117}
 118
 119static int mpd4_lvds_pll_set_rate(struct clk_hw *hw, unsigned long rate,
 120                unsigned long parent_rate)
 121{
 122        struct mdp4_lvds_pll *lvds_pll = to_mdp4_lvds_pll(hw);
 123        lvds_pll->pixclk = rate;
 124        return 0;
 125}
 126
 127
 128static const struct clk_ops mpd4_lvds_pll_ops = {
 129        .enable = mpd4_lvds_pll_enable,
 130        .disable = mpd4_lvds_pll_disable,
 131        .recalc_rate = mpd4_lvds_pll_recalc_rate,
 132        .round_rate = mpd4_lvds_pll_round_rate,
 133        .set_rate = mpd4_lvds_pll_set_rate,
 134};
 135
 136static const char *mpd4_lvds_pll_parents[] = {
 137        "pxo",
 138};
 139
 140static struct clk_init_data pll_init = {
 141        .name = "mpd4_lvds_pll",
 142        .ops = &mpd4_lvds_pll_ops,
 143        .parent_names = mpd4_lvds_pll_parents,
 144        .num_parents = ARRAY_SIZE(mpd4_lvds_pll_parents),
 145};
 146
 147struct clk *mpd4_lvds_pll_init(struct drm_device *dev)
 148{
 149        struct mdp4_lvds_pll *lvds_pll;
 150        struct clk *clk;
 151        int ret;
 152
 153        lvds_pll = devm_kzalloc(dev->dev, sizeof(*lvds_pll), GFP_KERNEL);
 154        if (!lvds_pll) {
 155                ret = -ENOMEM;
 156                goto fail;
 157        }
 158
 159        lvds_pll->dev = dev;
 160
 161        lvds_pll->pll_hw.init = &pll_init;
 162        clk = devm_clk_register(dev->dev, &lvds_pll->pll_hw);
 163        if (IS_ERR(clk)) {
 164                ret = PTR_ERR(clk);
 165                goto fail;
 166        }
 167
 168        return clk;
 169
 170fail:
 171        return ERR_PTR(ret);
 172}
 173