arch/arm/mach-pxa/mfp.c

   1 /*
   2  * linux/arch/arm/mach-pxa/mfp.c
   3  *
   4  * PXA3xx 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 <asm/hardware.h>
  23 #include <asm/arch/mfp.h>
  24 #include <asm/arch/mfp-pxa3xx.h>
  25
  26 /* mfp_spin_lock is used to ensure that MFP register configuration
  27  * (most likely a read-modify-write operation) is atomic, and that
  28  * mfp_table[] is consistent
  29  */
  30 static DEFINE_SPINLOCK(mfp_spin_lock);
  31
  32 static void __iomem *mfpr_mmio_base = (void __iomem *)&__REG(MFPR_BASE);
  33
  34 struct pxa3xx_mfp_pin {
  35         unsigned long   config;         /* -1 for not configured */
  36         unsigned long   mfpr_off;       /* MFPRxx Register offset */
  37         unsigned long   mfpr_run;       /* Run-Mode Register Value */
  38         unsigned long   mfpr_lpm;       /* Low Power Mode Register Value */
  39 };
  40
  41 static struct pxa3xx_mfp_pin mfp_table[MFP_PIN_MAX];
  42
  43 /* mapping of MFP_LPM_* definitions to MFPR_LPM_* register bits */
  44 const static unsigned long mfpr_lpm[] = {
  45         MFPR_LPM_INPUT,
  46         MFPR_LPM_DRIVE_LOW,
  47         MFPR_LPM_DRIVE_HIGH,
  48         MFPR_LPM_PULL_LOW,
  49         MFPR_LPM_PULL_HIGH,
  50         MFPR_LPM_FLOAT,
  51 };
  52
  53 /* mapping of MFP_PULL_* definitions to MFPR_PULL_* register bits */
  54 const static unsigned long mfpr_pull[] = {
  55         MFPR_PULL_NONE,
  56         MFPR_PULL_LOW,
  57         MFPR_PULL_HIGH,
  58         MFPR_PULL_BOTH,
  59 };
  60
  61 /* mapping of MFP_LPM_EDGE_* definitions to MFPR_EDGE_* register bits */
  62 const static unsigned long mfpr_edge[] = {
  63         MFPR_EDGE_NONE,
  64         MFPR_EDGE_RISE,
  65         MFPR_EDGE_FALL,
  66         MFPR_EDGE_BOTH,
  67 };
  68
  69 #define mfpr_readl(off)                 \
  70         __raw_readl(mfpr_mmio_base + (off))
  71
  72 #define mfpr_writel(off, val)           \
  73         __raw_writel(val, mfpr_mmio_base + (off))
  74
  75 #define mfp_configured(p)       ((p)->config != -1)
  76
  77 /*
  78  * perform a read-back of any MFPR register to make sure the
  79  * previous writings are finished
  80  */
  81 #define mfpr_sync()     (void)__raw_readl(mfpr_mmio_base + 0)
  82
  83 static inline void __mfp_config_run(struct pxa3xx_mfp_pin *p)
  84 {
  85         if (mfp_configured(p))
  86                 mfpr_writel(p->mfpr_off, p->mfpr_run);
  87 }
  88
  89 static inline void __mfp_config_lpm(struct pxa3xx_mfp_pin *p)
  90 {
  91         if (mfp_configured(p)) {
  92                 unsigned long mfpr_clr = (p->mfpr_run & ~MFPR_EDGE_BOTH) | MFPR_EDGE_CLEAR;
  93                 if (mfpr_clr != p->mfpr_run)
  94                         mfpr_writel(p->mfpr_off, mfpr_clr);
  95                 if (p->mfpr_lpm != mfpr_clr)
  96                         mfpr_writel(p->mfpr_off, p->mfpr_lpm);
  97         }
  98 }
  99
 100 void pxa3xx_mfp_config(unsigned long *mfp_cfgs, int num)
 101 {
 102         unsigned long flags;
 103         int i;
 104
 105         spin_lock_irqsave(&mfp_spin_lock, flags);
 106
 107         for (i = 0; i < num; i++, mfp_cfgs++) {
 108                 unsigned long tmp, c = *mfp_cfgs;
 109                 struct pxa3xx_mfp_pin *p;
 110                 int pin, af, drv, lpm, edge, pull;
 111
 112                 pin = MFP_PIN(c);
 113                 BUG_ON(pin >= MFP_PIN_MAX);
 114                 p = &mfp_table[pin];
 115
 116                 af  = MFP_AF(c);
 117                 drv = MFP_DS(c);
 118                 lpm = MFP_LPM_STATE(c);
 119                 edge = MFP_LPM_EDGE(c);
 120                 pull = MFP_PULL(c);
 121
 122                 /* run-mode pull settings will conflict with MFPR bits of
 123                  * low power mode state,  calculate mfpr_run and mfpr_lpm
 124                  * individually if pull != MFP_PULL_NONE
 125                  */
 126                 tmp = MFPR_AF_SEL(af) | MFPR_DRIVE(drv);
 127
 128                 if (likely(pull == MFP_PULL_NONE)) {
 129                         p->mfpr_run = tmp | mfpr_lpm[lpm] | mfpr_edge[edge];
 130                         p->mfpr_lpm = p->mfpr_run;
 131                 } else {
 132                         p->mfpr_lpm = tmp | mfpr_lpm[lpm] | mfpr_edge[edge];
 133                         p->mfpr_run = tmp | mfpr_pull[pull];
 134                 }
 135
 136                 p->config = c; __mfp_config_run(p);
 137         }
 138
 139         mfpr_sync();
 140         spin_unlock_irqrestore(&mfp_spin_lock, flags);
 141 }
 142
 143 unsigned long pxa3xx_mfp_read(int mfp)
 144 {
 145         unsigned long val, flags;
 146
 147         BUG_ON(mfp >= MFP_PIN_MAX);
 148
 149         spin_lock_irqsave(&mfp_spin_lock, flags);
 150         val = mfpr_readl(mfp_table[mfp].mfpr_off);
 151         spin_unlock_irqrestore(&mfp_spin_lock, flags);
 152
 153         return val;
 154 }
 155
 156 void pxa3xx_mfp_write(int mfp, unsigned long val)
 157 {
 158         unsigned long flags;
 159
 160         BUG_ON(mfp >= MFP_PIN_MAX);
 161
 162         spin_lock_irqsave(&mfp_spin_lock, flags);
 163         mfpr_writel(mfp_table[mfp].mfpr_off, val);
 164         mfpr_sync();
 165         spin_unlock_irqrestore(&mfp_spin_lock, flags);
 166 }
 167
 168 void __init pxa3xx_mfp_init_addr(struct pxa3xx_mfp_addr_map *map)
 169 {
 170         struct pxa3xx_mfp_addr_map *p;
 171         unsigned long offset, flags;
 172         int i;
 173
 174         spin_lock_irqsave(&mfp_spin_lock, flags);
 175
 176         for (p = map; p->start != MFP_PIN_INVALID; p++) {
 177                 offset = p->offset;
 178                 i = p->start;
 179
 180                 do {
 181                         mfp_table[i].mfpr_off = offset;
 182                         mfp_table[i].mfpr_run = 0;
 183                         mfp_table[i].mfpr_lpm = 0;
 184                         offset += 4; i++;
 185                 } while ((i <= p->end) && (p->end != -1));
 186         }
 187
 188         spin_unlock_irqrestore(&mfp_spin_lock, flags);
 189 }
 190
 191 void __init pxa3xx_init_mfp(void)
 192 {
 193         int i;
 194
 195         for (i = 0; i < ARRAY_SIZE(mfp_table); i++)
 196                 mfp_table[i].config = -1;
 197 }
 198
 199 #ifdef CONFIG_PM
 200 /*
 201  * Configure the MFPs appropriately for suspend/resume.
 202  * FIXME: this should probably depend on which system state we're
 203  * entering - for instance, we might not want to place MFP pins in
 204  * a pull-down mode if they're an active low chip select, and we're
 205  * just entering standby.
 206  */
 207 static int pxa3xx_mfp_suspend(struct sys_device *d, pm_message_t state)
 208 {
 209         int pin;
 210
 211         for (pin = 0; pin < ARRAY_SIZE(mfp_table); pin++) {
 212                 struct pxa3xx_mfp_pin *p = &mfp_table[pin];
 213                 __mfp_config_lpm(p);
 214         }
 215         return 0;
 216 }
 217
 218 static int pxa3xx_mfp_resume(struct sys_device *d)
 219 {
 220         int pin;
 221
 222         for (pin = 0; pin < ARRAY_SIZE(mfp_table); pin++) {
 223                 struct pxa3xx_mfp_pin *p = &mfp_table[pin];
 224                 __mfp_config_run(p);
 225         }
 226         return 0;
 227 }
 228
 229 static struct sysdev_class mfp_sysclass = {
 230         set_kset_name("mfp"),
 231         .suspend        = pxa3xx_mfp_suspend,
 232         .resume         = pxa3xx_mfp_resume,
 233 };
 234
 235 static struct sys_device mfp_device = {
 236         .id             = 0,
 237         .cls            = &mfp_sysclass,
 238 };
 239
 240 static int __init mfp_init_devicefs(void)
 241 {
 242         sysdev_class_register(&mfp_sysclass);
 243         return sysdev_register(&mfp_device);
 244 }
 245 device_initcall(mfp_init_devicefs);
 246 #endif