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
  21 #include <plat/mfp.h>
  22
  23 #define MFPR_SIZE       (PAGE_SIZE)
  24
  25 /* MFPR register bit definitions */
  26 #define MFPR_PULL_SEL           (0x1 << 15)
  27 #define MFPR_PULLUP_EN          (0x1 << 14)
  28 #define MFPR_PULLDOWN_EN        (0x1 << 13)
  29 #define MFPR_SLEEP_SEL          (0x1 << 9)
  30 #define MFPR_SLEEP_OE_N         (0x1 << 7)
  31 #define MFPR_EDGE_CLEAR         (0x1 << 6)
  32 #define MFPR_EDGE_FALL_EN       (0x1 << 5)
  33 #define MFPR_EDGE_RISE_EN       (0x1 << 4)
  34
  35 #define MFPR_SLEEP_DATA(x)      ((x) << 8)
  36 #define MFPR_DRIVE(x)           (((x) & 0x7) << 10)
  37 #define MFPR_AF_SEL(x)          (((x) & 0x7) << 0)
  38
  39 #define MFPR_EDGE_NONE          (0)
  40 #define MFPR_EDGE_RISE          (MFPR_EDGE_RISE_EN)
  41 #define MFPR_EDGE_FALL          (MFPR_EDGE_FALL_EN)
  42 #define MFPR_EDGE_BOTH          (MFPR_EDGE_RISE | MFPR_EDGE_FALL)
  43
  44 /*
  45  * Table that determines the low power modes outputs, with actual settings
  46  * used in parentheses for don't-care values. Except for the float output,
  47  * the configured driven and pulled levels match, so if there is a need for
  48  * non-LPM pulled output, the same configuration could probably be used.
  49  *
  50  * Output value  sleep_oe_n  sleep_data  pullup_en  pulldown_en  pull_sel
  51  *                 (bit 7)    (bit 8)    (bit 14)     (bit 13)   (bit 15)
  52  *
  53  * Input            0          X(0)        X(0)        X(0)       0
  54  * Drive 0          0          0           0           X(1)       0
  55  * Drive 1          0          1           X(1)        0          0
  56  * Pull hi (1)      1          X(1)        1           0          0
  57  * Pull lo (0)      1          X(0)        0           1          0
  58  * Z (float)        1          X(0)        0           0          0
  59  */
  60 #define MFPR_LPM_INPUT          (0)
  61 #define MFPR_LPM_DRIVE_LOW      (MFPR_SLEEP_DATA(0) | MFPR_PULLDOWN_EN)
  62 #define MFPR_LPM_DRIVE_HIGH     (MFPR_SLEEP_DATA(1) | MFPR_PULLUP_EN)
  63 #define MFPR_LPM_PULL_LOW       (MFPR_LPM_DRIVE_LOW  | MFPR_SLEEP_OE_N)
  64 #define MFPR_LPM_PULL_HIGH      (MFPR_LPM_DRIVE_HIGH | MFPR_SLEEP_OE_N)
  65 #define MFPR_LPM_FLOAT          (MFPR_SLEEP_OE_N)
  66 #define MFPR_LPM_MASK           (0xe080)
  67
  68 /*
  69  * The pullup and pulldown state of the MFP pin at run mode is by default
  70  * determined by the selected alternate function. In case that some buggy
  71  * devices need to override this default behavior,  the definitions below
  72  * indicates the setting of corresponding MFPR bits
  73  *
  74  * Definition       pull_sel  pullup_en  pulldown_en
  75  * MFPR_PULL_NONE       0         0        0
  76  * MFPR_PULL_LOW        1         0        1
  77  * MFPR_PULL_HIGH       1         1        0
  78  * MFPR_PULL_BOTH       1         1        1
  79  * MFPR_PULL_FLOAT      1         0        0
  80  */
  81 #define MFPR_PULL_NONE          (0)
  82 #define MFPR_PULL_LOW           (MFPR_PULL_SEL | MFPR_PULLDOWN_EN)
  83 #define MFPR_PULL_BOTH          (MFPR_PULL_LOW | MFPR_PULLUP_EN)
  84 #define MFPR_PULL_HIGH          (MFPR_PULL_SEL | MFPR_PULLUP_EN)
  85 #define MFPR_PULL_FLOAT         (MFPR_PULL_SEL)
  86
  87 /* mfp_spin_lock is used to ensure that MFP register configuration
  88  * (most likely a read-modify-write operation) is atomic, and that
  89  * mfp_table[] is consistent
  90  */
  91 static DEFINE_SPINLOCK(mfp_spin_lock);
  92
  93 static void __iomem *mfpr_mmio_base;
  94
  95 struct mfp_pin {
  96         unsigned long   config;         /* -1 for not configured */
  97         unsigned long   mfpr_off;       /* MFPRxx Register offset */
  98         unsigned long   mfpr_run;       /* Run-Mode Register Value */
  99         unsigned long   mfpr_lpm;       /* Low Power Mode Register Value */
 100 };
 101
 102 static struct mfp_pin mfp_table[MFP_PIN_MAX];
 103
 104 /* mapping of MFP_LPM_* definitions to MFPR_LPM_* register bits */
 105 static const unsigned long mfpr_lpm[] = {
 106         MFPR_LPM_INPUT,
 107         MFPR_LPM_DRIVE_LOW,
 108         MFPR_LPM_DRIVE_HIGH,
 109         MFPR_LPM_PULL_LOW,
 110         MFPR_LPM_PULL_HIGH,
 111         MFPR_LPM_FLOAT,
 112         MFPR_LPM_INPUT,
 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 valid MFPR register to make sure the
 142  * previous writings are finished
 143  */
 144 static unsigned long mfpr_off_readback;
 145 #define mfpr_sync()     (void)__raw_readl(mfpr_mmio_base + mfpr_off_readback)
 146
 147 static inline void __mfp_config_run(struct mfp_pin *p)
 148 {
 149         if (mfp_configured(p))
 150                 mfpr_writel(p->mfpr_off, p->mfpr_run);
 151 }
 152
 153 static inline void __mfp_config_lpm(struct mfp_pin *p)
 154 {
 155         if (mfp_configured(p)) {
 156                 unsigned long mfpr_clr = (p->mfpr_run & ~MFPR_EDGE_BOTH) | MFPR_EDGE_CLEAR;
 157                 if (mfpr_clr != p->mfpr_run)
 158                         mfpr_writel(p->mfpr_off, mfpr_clr);
 159                 if (p->mfpr_lpm != mfpr_clr)
 160                         mfpr_writel(p->mfpr_off, p->mfpr_lpm);
 161         }
 162 }
 163
 164 void mfp_config(unsigned long *mfp_cfgs, int num)
 165 {
 166         unsigned long flags;
 167         int i;
 168
 169         spin_lock_irqsave(&mfp_spin_lock, flags);
 170
 171         for (i = 0; i < num; i++, mfp_cfgs++) {
 172                 unsigned long tmp, c = *mfp_cfgs;
 173                 struct mfp_pin *p;
 174                 int pin, af, drv, lpm, edge, pull;
 175
 176                 pin = MFP_PIN(c);
 177                 BUG_ON(pin >= MFP_PIN_MAX);
 178                 p = &mfp_table[pin];
 179
 180                 af  = MFP_AF(c);
 181                 drv = MFP_DS(c);
 182                 lpm = MFP_LPM_STATE(c);
 183                 edge = MFP_LPM_EDGE(c);
 184                 pull = MFP_PULL(c);
 185
 186                 /* run-mode pull settings will conflict with MFPR bits of
 187                  * low power mode state,  calculate mfpr_run and mfpr_lpm
 188                  * individually if pull != MFP_PULL_NONE
 189                  */
 190                 tmp = MFPR_AF_SEL(af) | MFPR_DRIVE(drv);
 191
 192                 if (likely(pull == MFP_PULL_NONE)) {
 193                         p->mfpr_run = tmp | mfpr_lpm[lpm] | mfpr_edge[edge];
 194                         p->mfpr_lpm = p->mfpr_run;
 195                 } else {
 196                         p->mfpr_lpm = tmp | mfpr_lpm[lpm] | mfpr_edge[edge];
 197                         p->mfpr_run = tmp | mfpr_pull[pull];
 198                 }
 199
 200                 p->config = c; __mfp_config_run(p);
 201         }
 202
 203         mfpr_sync();
 204         spin_unlock_irqrestore(&mfp_spin_lock, flags);
 205 }
 206
 207 unsigned long mfp_read(int mfp)
 208 {
 209         unsigned long val, flags;
 210
 211         BUG_ON(mfp < 0 || mfp >= MFP_PIN_MAX);
 212
 213         spin_lock_irqsave(&mfp_spin_lock, flags);
 214         val = mfpr_readl(mfp_table[mfp].mfpr_off);
 215         spin_unlock_irqrestore(&mfp_spin_lock, flags);
 216
 217         return val;
 218 }
 219
 220 void mfp_write(int mfp, unsigned long val)
 221 {
 222         unsigned long flags;
 223
 224         BUG_ON(mfp < 0 || mfp >= MFP_PIN_MAX);
 225
 226         spin_lock_irqsave(&mfp_spin_lock, flags);
 227         mfpr_writel(mfp_table[mfp].mfpr_off, val);
 228         mfpr_sync();
 229         spin_unlock_irqrestore(&mfp_spin_lock, flags);
 230 }
 231
 232 void __init mfp_init_base(void __iomem *mfpr_base)
 233 {
 234         int i;
 235
 236         /* initialize the table with default - unconfigured */
 237         for (i = 0; i < ARRAY_SIZE(mfp_table); i++)
 238                 mfp_table[i].config = -1;
 239
 240         mfpr_mmio_base = mfpr_base;
 241 }
 242
 243 void __init mfp_init_addr(struct mfp_addr_map *map)
 244 {
 245         struct mfp_addr_map *p;
 246         unsigned long offset, flags;
 247         int i;
 248
 249         spin_lock_irqsave(&mfp_spin_lock, flags);
 250
 251         /* mfp offset for readback */
 252         mfpr_off_readback = map[0].offset;
 253
 254         for (p = map; p->start != MFP_PIN_INVALID; p++) {
 255                 offset = p->offset;
 256                 i = p->start;
 257
 258                 do {
 259                         mfp_table[i].mfpr_off = offset;
 260                         mfp_table[i].mfpr_run = 0;
 261                         mfp_table[i].mfpr_lpm = 0;
 262                         offset += 4; i++;
 263                 } while ((i <= p->end) && (p->end != -1));
 264         }
 265
 266         spin_unlock_irqrestore(&mfp_spin_lock, flags);
 267 }
 268
 269 void mfp_config_lpm(void)
 270 {
 271         struct mfp_pin *p = &mfp_table[0];
 272         int pin;
 273
 274         for (pin = 0; pin < ARRAY_SIZE(mfp_table); pin++, p++)
 275                 __mfp_config_lpm(p);
 276 }
 277
 278 void mfp_config_run(void)
 279 {
 280         struct mfp_pin *p = &mfp_table[0];
 281         int pin;
 282
 283         for (pin = 0; pin < ARRAY_SIZE(mfp_table); pin++, p++)
 284                 __mfp_config_run(p);
 285 }