sound/soc/sh/rcar/adg.c

   1 /*
   2  * Helper routines for R-Car sound ADG.
   3  *
   4  *  Copyright (C) 2013  Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
   5  *
   6  * This file is subject to the terms and conditions of the GNU General Public
   7  * License.  See the file "COPYING" in the main directory of this archive
   8  * for more details.
   9  */
  10 #include <linux/sh_clk.h>
  11 #include "rsnd.h"
  12
  13 #define CLKA    0
  14 #define CLKB    1
  15 #define CLKC    2
  16 #define CLKI    3
  17 #define CLKMAX  4
  18
  19 struct rsnd_adg {
  20         struct clk *clk[CLKMAX];
  21
  22         int rate_of_441khz_div_6;
  23         int rate_of_48khz_div_6;
  24         u32 ckr;
  25 };
  26
  27 #define for_each_rsnd_clk(pos, adg, i)          \
  28         for (i = 0, (pos) = adg->clk[i];        \
  29              i < CLKMAX;                        \
  30              i++, (pos) = adg->clk[i])
  31 #define rsnd_priv_to_adg(priv) ((struct rsnd_adg *)(priv)->adg)
  32
  33 static enum rsnd_reg rsnd_adg_ssi_reg_get(int id)
  34 {
  35         enum rsnd_reg reg;
  36
  37         /*
  38          * SSI 8 is not connected to ADG.
  39          * it works with SSI 7
  40          */
  41         if (id == 8)
  42                 return RSND_REG_MAX;
  43
  44         if (0 <= id && id <= 3)
  45                 reg = RSND_REG_AUDIO_CLK_SEL0;
  46         else if (4 <= id && id <= 7)
  47                 reg = RSND_REG_AUDIO_CLK_SEL1;
  48         else
  49                 reg = RSND_REG_AUDIO_CLK_SEL2;
  50
  51         return reg;
  52 }
  53
  54 int rsnd_adg_ssi_clk_stop(struct rsnd_mod *mod)
  55 {
  56         struct rsnd_priv *priv = rsnd_mod_to_priv(mod);
  57         enum rsnd_reg reg;
  58         int id;
  59
  60         /*
  61          * "mod" = "ssi" here.
  62          * we can get "ssi id" from mod
  63          */
  64         id  = rsnd_mod_id(mod);
  65         reg = rsnd_adg_ssi_reg_get(id);
  66
  67         rsnd_write(priv, mod, reg, 0);
  68
  69         return 0;
  70 }
  71
  72 int rsnd_adg_ssi_clk_try_start(struct rsnd_mod *mod, unsigned int rate)
  73 {
  74         struct rsnd_priv *priv = rsnd_mod_to_priv(mod);
  75         struct rsnd_adg *adg = rsnd_priv_to_adg(priv);
  76         struct device *dev = rsnd_priv_to_dev(priv);
  77         struct clk *clk;
  78         enum rsnd_reg reg;
  79         int id, shift, i;
  80         u32 data;
  81         int sel_table[] = {
  82                 [CLKA] = 0x1,
  83                 [CLKB] = 0x2,
  84                 [CLKC] = 0x3,
  85                 [CLKI] = 0x0,
  86         };
  87
  88         dev_dbg(dev, "request clock = %d\n", rate);
  89
  90         /*
  91          * find suitable clock from
  92          * AUDIO_CLKA/AUDIO_CLKB/AUDIO_CLKC/AUDIO_CLKI.
  93          */
  94         data = 0;
  95         for_each_rsnd_clk(clk, adg, i) {
  96                 if (rate == clk_get_rate(clk)) {
  97                         data = sel_table[i];
  98                         goto found_clock;
  99                 }
 100         }
 101
 102         /*
 103          * find 1/6 clock from BRGA/BRGB
 104          */
 105         if (rate == adg->rate_of_441khz_div_6) {
 106                 data = 0x10;
 107                 goto found_clock;
 108         }
 109
 110         if (rate == adg->rate_of_48khz_div_6) {
 111                 data = 0x20;
 112                 goto found_clock;
 113         }
 114
 115         return -EIO;
 116
 117 found_clock:
 118
 119         /* see rsnd_adg_ssi_clk_init() */
 120         rsnd_mod_bset(mod, SSICKR, 0x00FF0000, adg->ckr);
 121         rsnd_mod_write(mod, BRRA,  0x00000002); /* 1/6 */
 122         rsnd_mod_write(mod, BRRB,  0x00000002); /* 1/6 */
 123
 124         /*
 125          * This "mod" = "ssi" here.
 126          * we can get "ssi id" from mod
 127          */
 128         id  = rsnd_mod_id(mod);
 129         reg = rsnd_adg_ssi_reg_get(id);
 130
 131         dev_dbg(dev, "ADG: ssi%d selects clk%d = %d", id, i, rate);
 132
 133         /*
 134          * Enable SSIx clock
 135          */
 136         shift = (id % 4) * 8;
 137
 138         rsnd_bset(priv, mod, reg,
 139                    0xFF << shift,
 140                    data << shift);
 141
 142         return 0;
 143 }
 144
 145 static void rsnd_adg_ssi_clk_init(struct rsnd_priv *priv, struct rsnd_adg *adg)
 146 {
 147         struct clk *clk;
 148         unsigned long rate;
 149         u32 ckr;
 150         int i;
 151         int brg_table[] = {
 152                 [CLKA] = 0x0,
 153                 [CLKB] = 0x1,
 154                 [CLKC] = 0x4,
 155                 [CLKI] = 0x2,
 156         };
 157
 158         /*
 159          * This driver is assuming that AUDIO_CLKA/AUDIO_CLKB/AUDIO_CLKC
 160          * have 44.1kHz or 48kHz base clocks for now.
 161          *
 162          * SSI itself can divide parent clock by 1/1 - 1/16
 163          * So,  BRGA outputs 44.1kHz base parent clock 1/32,
 164          * and, BRGB outputs 48.0kHz base parent clock 1/32 here.
 165          * see
 166          *      rsnd_adg_ssi_clk_try_start()
 167          */
 168         ckr = 0;
 169         adg->rate_of_441khz_div_6 = 0;
 170         adg->rate_of_48khz_div_6  = 0;
 171         for_each_rsnd_clk(clk, adg, i) {
 172                 rate = clk_get_rate(clk);
 173
 174                 if (0 == rate) /* not used */
 175                         continue;
 176
 177                 /* RBGA */
 178                 if (!adg->rate_of_441khz_div_6 && (0 == rate % 44100)) {
 179                         adg->rate_of_441khz_div_6 = rate / 6;
 180                         ckr |= brg_table[i] << 20;
 181                 }
 182
 183                 /* RBGB */
 184                 if (!adg->rate_of_48khz_div_6 && (0 == rate % 48000)) {
 185                         adg->rate_of_48khz_div_6 = rate / 6;
 186                         ckr |= brg_table[i] << 16;
 187                 }
 188         }
 189
 190         adg->ckr = ckr;
 191 }
 192
 193 int rsnd_adg_probe(struct platform_device *pdev,
 194                    struct rcar_snd_info *info,
 195                    struct rsnd_priv *priv)
 196 {
 197         struct rsnd_adg *adg;
 198         struct device *dev = rsnd_priv_to_dev(priv);
 199         struct clk *clk;
 200         int i;
 201
 202         adg = devm_kzalloc(dev, sizeof(*adg), GFP_KERNEL);
 203         if (!adg) {
 204                 dev_err(dev, "ADG allocate failed\n");
 205                 return -ENOMEM;
 206         }
 207
 208         adg->clk[CLKA] = clk_get(NULL, "audio_clk_a");
 209         adg->clk[CLKB] = clk_get(NULL, "audio_clk_b");
 210         adg->clk[CLKC] = clk_get(NULL, "audio_clk_c");
 211         adg->clk[CLKI] = clk_get(NULL, "audio_clk_internal");
 212         for_each_rsnd_clk(clk, adg, i) {
 213                 if (IS_ERR(clk)) {
 214                         dev_err(dev, "Audio clock failed\n");
 215                         return -EIO;
 216                 }
 217         }
 218
 219         rsnd_adg_ssi_clk_init(priv, adg);
 220
 221         priv->adg = adg;
 222
 223         dev_dbg(dev, "adg probed\n");
 224
 225         return 0;
 226 }
 227
 228 void rsnd_adg_remove(struct platform_device *pdev,
 229                      struct rsnd_priv *priv)
 230 {
 231         struct rsnd_adg *adg = priv->adg;
 232         struct clk *clk;
 233         int i;
 234
 235         for_each_rsnd_clk(clk, adg, i)
 236                 clk_put(clk);
 237 }