arch/arm/plat-pxa/mfp.c

   1 /*
   2  * linux/arch/arm/plat-pxa/mfp.c
   3  *
   4  *   Multi-Function Pin Support
   5  *
   6  * Copyright (C) 2007 Marvell Internation Ltd.
   7  *
   8  * 2007-08-21: eric miao <eric.miao@marvell.com>
   9  *             initial version
  10  *
  11  *  This program is free software; you can redistribute it and/or modify
  12  *  it under the terms of the GNU General Public License version 2 as
  13  *  published by the Free Software Foundation.
  14  */
  15
  16 #include <linux/module.h>
  17 #include <linux/kernel.h>
  18 #include <linux/init.h>
  19 #include <linux/io.h>
  20 #include <linux/sysdev.h>
  21
  22 #include <plat/mfp.h>
  23
  24 #define MFPR_SIZE       (PAGE_SIZE)
  25
  26 /* MFPR register bit definitions */
  27 #define MFPR_PULL_SEL           (0x1 << 15)
  28 #define MFPR_PULLUP_EN          (0x1 << 14)
  29 #define MFPR_PULLDOWN_EN        (0x1 << 13)
  30 #define MFPR_SLEEP_SEL          (0x1 << 9)
  31 #define MFPR_SLEEP_OE_N         (0x1 << 7)
  32 #define MFPR_EDGE_CLEAR         (0x1 << 6)
  33 #define MFPR_EDGE_FALL_EN       (0x1 << 5)
  34 #define MFPR_EDGE_RISE_EN       (0x1 << 4)
  35
  36 #define MFPR_SLEEP_DATA(x)      ((x) << 8)
  37 #define MFPR_DRIVE(x)           (((x) & 0x7) << 10)
  38 #define MFPR_AF_SEL(x)          (((x) & 0x7) << 0)
  39
  40 #define MFPR_EDGE_NONE          (0)
  41 #define MFPR_EDGE_RISE          (MFPR_EDGE_RISE_EN)
  42 #define MFPR_EDGE_FALL          (MFPR_EDGE_FALL_EN)
  43 #define MFPR_EDGE_BOTH          (MFPR_EDGE_RISE | MFPR_EDGE_FALL)
  44
  45 /*
  46  * Table that determines the low power modes outputs, with actual settings
  47  * used in parentheses for don't-care values. Except for the float output,
  48  * the configured driven and pulled levels match, so if there is a need for
  49  * non-LPM pulled output, the same configuration could probably be used.
  50  *
  51  * Output value  sleep_oe_n  sleep_data  pullup_en  pulldown_en  pull_sel
  52  *                 (bit 7)    (bit 8)    (bit 14)     (bit 13)   (bit 15)
  53  *
  54  * Input            0          X(0)        X(0)        X(0)       0
  55  * Drive 0          0          0           0           X(1)       0
  56  * Drive 1          0          1           X(1)        0          0
  57  * Pull hi (1)      1          X(1)        1           0          0
  58  * Pull lo (0)      1          X(0)        0           1          0
  59  * Z (float)        1          X(0)        0           0          0
  60  */
  61 #define MFPR_LPM_INPUT          (0)
  62 #define MFPR_LPM_DRIVE_LOW      (MFPR_SLEEP_DATA(0) | MFPR_PULLDOWN_EN)
  63 #define MFPR_LPM_DRIVE_HIGH     (MFPR_SLEEP_DATA(1) | MFPR_PULLUP_EN)
  64 #define MFPR_LPM_PULL_LOW       (MFPR_LPM_DRIVE_LOW  | MFPR_SLEEP_OE_N)
  65 #define MFPR_LPM_PULL_HIGH      (MFPR_LPM_DRIVE_HIGH | MFPR_SLEEP_OE_N)
  66 #define MFPR_LPM_FLOAT          (MFPR_SLEEP_OE_N)
  67 #define MFPR_LPM_MASK           (0xe080)
  68
  69 /*
  70  * The pullup and pulldown state of the MFP pin at run mode is by default
  71  * determined by the selected alternate function. In case that some buggy
  72  * devices need to override this default behavior,  the definitions below
  73  * indicates the setting of corresponding MFPR bits
  74  *
  75  * Definition       pull_sel  pullup_en  pulldown_en
  76  * MFPR_PULL_NONE       0         0        0
  77  * MFPR_PULL_LOW        1         0        1
  78  * MFPR_PULL_HIGH       1         1        0
  79  * MFPR_PULL_BOTH       1         1        1
  80  * MFPR_PULL_FLOAT      1         0        0
  81  */
  82 #define MFPR_PULL_NONE          (0)
  83 #define MFPR_PULL_LOW           (MFPR_PULL_SEL | MFPR_PULLDOWN_EN)
  84 #define MFPR_PULL_BOTH          (MFPR_PULL_LOW | MFPR_PULLUP_EN)
  85 #define MFPR_PULL_HIGH          (MFPR_PULL_SEL | MFPR_PULLUP_EN)
  86 #define MFPR_PULL_FLOAT         (MFPR_PULL_SEL)
  87
  88 /* mfp_spin_lock is used to ensure that MFP register configuration
  89  * (most likely a read-modify-write operation) is atomic, and that
  90  * mfp_table[] is consistent
  91  */
  92 static DEFINE_SPINLOCK(mfp_spin_lock);
  93
  94 static void __iomem *mfpr_mmio_base;
  95
  96 struct mfp_pin {
  97         unsigned long   config;         /* -1 for not configured */
  98         unsigned long   mfpr_off;       /* MFPRxx Register offset */
  99         unsigned long   mfpr_run;       /* Run-Mode Register Value */
 100         unsigned long   mfpr_lpm;       /* Low Power Mode Register Value */
 101 };
 102
 103 static struct mfp_pin mfp_table[MFP_PIN_MAX];
 104
 105 /* mapping of MFP_LPM_* definitions to MFPR_LPM_* register bits */
 106 static const unsigned long mfpr_lpm[] = {
 107         MFPR_LPM_INPUT,
 108         MFPR_LPM_DRIVE_LOW,
 109         MFPR_LPM_DRIVE_HIGH,
 110         MFPR_LPM_PULL_LOW,
 111         MFPR_LPM_PULL_HIGH,
 112         MFPR_LPM_FLOAT,
 113 };
 114
 115 /* mapping of MFP_PULL_* definitions to MFPR_PULL_* register bits */
 116 static const unsigned long mfpr_pull[] = {
 117         MFPR_PULL_NONE,
 118         MFPR_PULL_LOW,
 119         MFPR_PULL_HIGH,
 120         MFPR_PULL_BOTH,
 121         MFPR_PULL_FLOAT,
 122 };
 123
 124 /* mapping of MFP_LPM_EDGE_* definitions to MFPR_EDGE_* register bits */
 125 static const unsigned long mfpr_edge[] = {
 126         MFPR_EDGE_NONE,
 127         MFPR_EDGE_RISE,
 128         MFPR_EDGE_FALL,
 129         MFPR_EDGE_BOTH,
 130 };
 131
 132 #define mfpr_readl(off)                 \
 133         __raw_readl(mfpr_mmio_base + (off))
 134
 135 #define mfpr_writel(off, val)           \
 136         __raw_writel(val, mfpr_mmio_base + (off))
 137
 138 #define mfp_configured(p)       ((p)->config != -1)
 139
 140 /*
 141  * perform a read-back of any MFPR register to make sure the
 142  * previous writings are finished
 143  */
 144 #define mfpr_sync()     (void)__raw_readl(mfpr_mmio_base + 0)
 145
 146 static inline void __mfp_config_run(struct mfp_pin *p)
 147 {
 148         if (mfp_configured(p))
 149                 mfpr_writel(p->mfpr_off, p->mfpr_run);
 150 }
 151
 152 static inline void __mfp_config_lpm(struct mfp_pin *p)
 153 {
 154         if (mfp_configured(p)) {
 155                 unsigned long mfpr_clr = (p->mfpr_run & ~MFPR_EDGE_BOTH) | MFPR_EDGE_CLEAR;
 156                 if (mfpr_clr != p->mfpr_run)
 157                         mfpr_writel(p->mfpr_off, mfpr_clr);
 158                 if (p->mfpr_lpm != mfpr_clr)
 159                         mfpr_writel(p->mfpr_off, p->mfpr_lpm);
 160         }
 161 }
 162
 163 void mfp_config(unsigned long *mfp_cfgs, int num)
 164 {
 165         unsigned long flags;
 166         int i;
 167
 168         spin_lock_irqsave(&mfp_spin_lock, flags);
 169
 170         for (i = 0; i < num; i++, mfp_cfgs++) {
 171                 unsigned long tmp, c = *mfp_cfgs;
 172                 struct mfp_pin *p;
 173                 int pin, af, drv, lpm, edge, pull;
 174
 175                 pin = MFP_PIN(c);
 176                 BUG_ON(pin >= MFP_PIN_MAX);
 177                 p = &mfp_table[pin];
 178
 179                 af  = MFP_AF(c);
 180                 drv = MFP_DS(c);
 181                 lpm = MFP_LPM_STATE(c);
 182                 edge = MFP_LPM_EDGE(c);
 183                 pull = MFP_PULL(c);
 184
 185                 /* run-mode pull settings will conflict with MFPR bits of
 186                  * low power mode state,  calculate mfpr_run and mfpr_lpm
 187                  * individually if pull != MFP_PULL_NONE
 188                  */
 189                 tmp = MFPR_AF_SEL(af) | MFPR_DRIVE(drv);
 190
 191                 if (likely(pull == MFP_PULL_NONE)) {
 192                         p->mfpr_run = tmp | mfpr_lpm[lpm] | mfpr_edge[edge];
 193                         p->mfpr_lpm = p->mfpr_run;
 194                 } else {
 195                         p->mfpr_lpm = tmp | mfpr_lpm[lpm] | mfpr_edge[edge];
 196                         p->mfpr_run = tmp | mfpr_pull[pull];
 197                 }
 198
 199                 p->config = c; __mfp_config_run(p);
 200         }
 201
 202         mfpr_sync();
 203         spin_unlock_irqrestore(&mfp_spin_lock, flags);
 204 }
 205
 206 unsigned long mfp_read(int mfp)
 207 {
 208         unsigned long val, flags;
 209
 210         BUG_ON(mfp < 0 || mfp >= MFP_PIN_MAX);
 211
 212         spin_lock_irqsave(&mfp_spin_lock, flags);
 213         val = mfpr_readl(mfp_table[mfp].mfpr_off);
 214         spin_unlock_irqrestore(&mfp_spin_lock, flags);
 215
 216         return val;
 217 }
 218
 219 void mfp_write(int mfp, unsigned long val)
 220 {
 221         unsigned long flags;
 222
 223         BUG_ON(mfp < 0 || mfp >= MFP_PIN_MAX);
 224
 225         spin_lock_irqsave(&mfp_spin_lock, flags);
 226         mfpr_writel(mfp_table[mfp].mfpr_off, val);
 227         mfpr_sync();
 228         spin_unlock_irqrestore(&mfp_spin_lock, flags);
 229 }
 230
 231 void __init mfp_init_base(unsigned long mfpr_base)
 232 {
 233         int i;
 234
 235         /* initialize the table with default - unconfigured */
 236         for (i = 0; i < ARRAY_SIZE(mfp_table); i++)
 237                 mfp_table[i].config = -1;
 238
 239         mfpr_mmio_base = (void __iomem *)mfpr_base;
 240 }
 241
 242 void __init mfp_init_addr(struct mfp_addr_map *map)
 243 {
 244         struct mfp_addr_map *p;
 245         unsigned long offset, flags;
 246         int i;
 247
 248         spin_lock_irqsave(&mfp_spin_lock, flags);
 249
 250         for (p = map; p->start != MFP_PIN_INVALID; p++) {
 251                 offset = p->offset;
 252                 i = p->start;
 253
 254                 do {
 255                         mfp_table[i].mfpr_off = offset;
 256                         mfp_table[i].mfpr_run = 0;
 257                         mfp_table[i].mfpr_lpm = 0;
 258                         offset += 4; i++;
 259                 } while ((i <= p->end) && (p->end != -1));
 260         }
 261
 262         spin_unlock_irqrestore(&mfp_spin_lock, flags);
 263 }
 264
 265 void mfp_config_lpm(void)
 266 {
 267         struct mfp_pin *p = &mfp_table[0];
 268         int pin;
 269
 270         for (pin = 0; pin < ARRAY_SIZE(mfp_table); pin++, p++)
 271                 __mfp_config_lpm(p);
 272 }
 273
 274 void mfp_config_run(void)
 275 {
 276         struct mfp_pin *p = &mfp_table[0];
 277         int pin;
 278
 279         for (pin = 0; pin < ARRAY_SIZE(mfp_table); pin++, p++)
 280                 __mfp_config_run(p);
 281 }