diff options
Diffstat (limited to 'kernel/arch/arm/plat-pxa/mfp.c')
| -rw-r--r-- | kernel/arch/arm/plat-pxa/mfp.c | 285 |
1 files changed, 285 insertions, 0 deletions
diff --git a/kernel/arch/arm/plat-pxa/mfp.c b/kernel/arch/arm/plat-pxa/mfp.c new file mode 100644 index 000000000..2c4dbb1f4 --- /dev/null +++ b/kernel/arch/arm/plat-pxa/mfp.c @@ -0,0 +1,285 @@ +/* + * linux/arch/arm/plat-pxa/mfp.c + * + * Multi-Function Pin Support + * + * Copyright (C) 2007 Marvell Internation Ltd. + * + * 2007-08-21: eric miao <eric.miao@marvell.com> + * initial version + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/io.h> + +#include <plat/mfp.h> + +#define MFPR_SIZE (PAGE_SIZE) + +/* MFPR register bit definitions */ +#define MFPR_PULL_SEL (0x1 << 15) +#define MFPR_PULLUP_EN (0x1 << 14) +#define MFPR_PULLDOWN_EN (0x1 << 13) +#define MFPR_SLEEP_SEL (0x1 << 9) +#define MFPR_SLEEP_OE_N (0x1 << 7) +#define MFPR_EDGE_CLEAR (0x1 << 6) +#define MFPR_EDGE_FALL_EN (0x1 << 5) +#define MFPR_EDGE_RISE_EN (0x1 << 4) + +#define MFPR_SLEEP_DATA(x) ((x) << 8) +#define MFPR_DRIVE(x) (((x) & 0x7) << 10) +#define MFPR_AF_SEL(x) (((x) & 0x7) << 0) + +#define MFPR_EDGE_NONE (0) +#define MFPR_EDGE_RISE (MFPR_EDGE_RISE_EN) +#define MFPR_EDGE_FALL (MFPR_EDGE_FALL_EN) +#define MFPR_EDGE_BOTH (MFPR_EDGE_RISE | MFPR_EDGE_FALL) + +/* + * Table that determines the low power modes outputs, with actual settings + * used in parentheses for don't-care values. Except for the float output, + * the configured driven and pulled levels match, so if there is a need for + * non-LPM pulled output, the same configuration could probably be used. + * + * Output value sleep_oe_n sleep_data pullup_en pulldown_en pull_sel + * (bit 7) (bit 8) (bit 14) (bit 13) (bit 15) + * + * Input 0 X(0) X(0) X(0) 0 + * Drive 0 0 0 0 X(1) 0 + * Drive 1 0 1 X(1) 0 0 + * Pull hi (1) 1 X(1) 1 0 0 + * Pull lo (0) 1 X(0) 0 1 0 + * Z (float) 1 X(0) 0 0 0 + */ +#define MFPR_LPM_INPUT (0) +#define MFPR_LPM_DRIVE_LOW (MFPR_SLEEP_DATA(0) | MFPR_PULLDOWN_EN) +#define MFPR_LPM_DRIVE_HIGH (MFPR_SLEEP_DATA(1) | MFPR_PULLUP_EN) +#define MFPR_LPM_PULL_LOW (MFPR_LPM_DRIVE_LOW | MFPR_SLEEP_OE_N) +#define MFPR_LPM_PULL_HIGH (MFPR_LPM_DRIVE_HIGH | MFPR_SLEEP_OE_N) +#define MFPR_LPM_FLOAT (MFPR_SLEEP_OE_N) +#define MFPR_LPM_MASK (0xe080) + +/* + * The pullup and pulldown state of the MFP pin at run mode is by default + * determined by the selected alternate function. In case that some buggy + * devices need to override this default behavior, the definitions below + * indicates the setting of corresponding MFPR bits + * + * Definition pull_sel pullup_en pulldown_en + * MFPR_PULL_NONE 0 0 0 + * MFPR_PULL_LOW 1 0 1 + * MFPR_PULL_HIGH 1 1 0 + * MFPR_PULL_BOTH 1 1 1 + * MFPR_PULL_FLOAT 1 0 0 + */ +#define MFPR_PULL_NONE (0) +#define MFPR_PULL_LOW (MFPR_PULL_SEL | MFPR_PULLDOWN_EN) +#define MFPR_PULL_BOTH (MFPR_PULL_LOW | MFPR_PULLUP_EN) +#define MFPR_PULL_HIGH (MFPR_PULL_SEL | MFPR_PULLUP_EN) +#define MFPR_PULL_FLOAT (MFPR_PULL_SEL) + +/* mfp_spin_lock is used to ensure that MFP register configuration + * (most likely a read-modify-write operation) is atomic, and that + * mfp_table[] is consistent + */ +static DEFINE_SPINLOCK(mfp_spin_lock); + +static void __iomem *mfpr_mmio_base; + +struct mfp_pin { + unsigned long config; /* -1 for not configured */ + unsigned long mfpr_off; /* MFPRxx Register offset */ + unsigned long mfpr_run; /* Run-Mode Register Value */ + unsigned long mfpr_lpm; /* Low Power Mode Register Value */ +}; + +static struct mfp_pin mfp_table[MFP_PIN_MAX]; + +/* mapping of MFP_LPM_* definitions to MFPR_LPM_* register bits */ +static const unsigned long mfpr_lpm[] = { + MFPR_LPM_INPUT, + MFPR_LPM_DRIVE_LOW, + MFPR_LPM_DRIVE_HIGH, + MFPR_LPM_PULL_LOW, + MFPR_LPM_PULL_HIGH, + MFPR_LPM_FLOAT, + MFPR_LPM_INPUT, +}; + +/* mapping of MFP_PULL_* definitions to MFPR_PULL_* register bits */ +static const unsigned long mfpr_pull[] = { + MFPR_PULL_NONE, + MFPR_PULL_LOW, + MFPR_PULL_HIGH, + MFPR_PULL_BOTH, + MFPR_PULL_FLOAT, +}; + +/* mapping of MFP_LPM_EDGE_* definitions to MFPR_EDGE_* register bits */ +static const unsigned long mfpr_edge[] = { + MFPR_EDGE_NONE, + MFPR_EDGE_RISE, + MFPR_EDGE_FALL, + MFPR_EDGE_BOTH, +}; + +#define mfpr_readl(off) \ + __raw_readl(mfpr_mmio_base + (off)) + +#define mfpr_writel(off, val) \ + __raw_writel(val, mfpr_mmio_base + (off)) + +#define mfp_configured(p) ((p)->config != -1) + +/* + * perform a read-back of any valid MFPR register to make sure the + * previous writings are finished + */ +static unsigned long mfpr_off_readback; +#define mfpr_sync() (void)__raw_readl(mfpr_mmio_base + mfpr_off_readback) + +static inline void __mfp_config_run(struct mfp_pin *p) +{ + if (mfp_configured(p)) + mfpr_writel(p->mfpr_off, p->mfpr_run); +} + +static inline void __mfp_config_lpm(struct mfp_pin *p) +{ + if (mfp_configured(p)) { + unsigned long mfpr_clr = (p->mfpr_run & ~MFPR_EDGE_BOTH) | MFPR_EDGE_CLEAR; + if (mfpr_clr != p->mfpr_run) + mfpr_writel(p->mfpr_off, mfpr_clr); + if (p->mfpr_lpm != mfpr_clr) + mfpr_writel(p->mfpr_off, p->mfpr_lpm); + } +} + +void mfp_config(unsigned long *mfp_cfgs, int num) +{ + unsigned long flags; + int i; + + spin_lock_irqsave(&mfp_spin_lock, flags); + + for (i = 0; i < num; i++, mfp_cfgs++) { + unsigned long tmp, c = *mfp_cfgs; + struct mfp_pin *p; + int pin, af, drv, lpm, edge, pull; + + pin = MFP_PIN(c); + BUG_ON(pin >= MFP_PIN_MAX); + p = &mfp_table[pin]; + + af = MFP_AF(c); + drv = MFP_DS(c); + lpm = MFP_LPM_STATE(c); + edge = MFP_LPM_EDGE(c); + pull = MFP_PULL(c); + + /* run-mode pull settings will conflict with MFPR bits of + * low power mode state, calculate mfpr_run and mfpr_lpm + * individually if pull != MFP_PULL_NONE + */ + tmp = MFPR_AF_SEL(af) | MFPR_DRIVE(drv); + + if (likely(pull == MFP_PULL_NONE)) { + p->mfpr_run = tmp | mfpr_lpm[lpm] | mfpr_edge[edge]; + p->mfpr_lpm = p->mfpr_run; + } else { + p->mfpr_lpm = tmp | mfpr_lpm[lpm] | mfpr_edge[edge]; + p->mfpr_run = tmp | mfpr_pull[pull]; + } + + p->config = c; __mfp_config_run(p); + } + + mfpr_sync(); + spin_unlock_irqrestore(&mfp_spin_lock, flags); +} + +unsigned long mfp_read(int mfp) +{ + unsigned long val, flags; + + BUG_ON(mfp < 0 || mfp >= MFP_PIN_MAX); + + spin_lock_irqsave(&mfp_spin_lock, flags); + val = mfpr_readl(mfp_table[mfp].mfpr_off); + spin_unlock_irqrestore(&mfp_spin_lock, flags); + + return val; +} + +void mfp_write(int mfp, unsigned long val) +{ + unsigned long flags; + + BUG_ON(mfp < 0 || mfp >= MFP_PIN_MAX); + + spin_lock_irqsave(&mfp_spin_lock, flags); + mfpr_writel(mfp_table[mfp].mfpr_off, val); + mfpr_sync(); + spin_unlock_irqrestore(&mfp_spin_lock, flags); +} + +void __init mfp_init_base(void __iomem *mfpr_base) +{ + int i; + + /* initialize the table with default - unconfigured */ + for (i = 0; i < ARRAY_SIZE(mfp_table); i++) + mfp_table[i].config = -1; + + mfpr_mmio_base = mfpr_base; +} + +void __init mfp_init_addr(struct mfp_addr_map *map) +{ + struct mfp_addr_map *p; + unsigned long offset, flags; + int i; + + spin_lock_irqsave(&mfp_spin_lock, flags); + + /* mfp offset for readback */ + mfpr_off_readback = map[0].offset; + + for (p = map; p->start != MFP_PIN_INVALID; p++) { + offset = p->offset; + i = p->start; + + do { + mfp_table[i].mfpr_off = offset; + mfp_table[i].mfpr_run = 0; + mfp_table[i].mfpr_lpm = 0; + offset += 4; i++; + } while ((i <= p->end) && (p->end != -1)); + } + + spin_unlock_irqrestore(&mfp_spin_lock, flags); +} + +void mfp_config_lpm(void) +{ + struct mfp_pin *p = &mfp_table[0]; + int pin; + + for (pin = 0; pin < ARRAY_SIZE(mfp_table); pin++, p++) + __mfp_config_lpm(p); +} + +void mfp_config_run(void) +{ + struct mfp_pin *p = &mfp_table[0]; + int pin; + + for (pin = 0; pin < ARRAY_SIZE(mfp_table); pin++, p++) + __mfp_config_run(p); +} |