diff options
Diffstat (limited to 'arch/arm/mach-pxa/mfp-pxa3xx.c')
| -rw-r--r-- | arch/arm/mach-pxa/mfp-pxa3xx.c | 255 |
1 files changed, 255 insertions, 0 deletions
diff --git a/arch/arm/mach-pxa/mfp-pxa3xx.c b/arch/arm/mach-pxa/mfp-pxa3xx.c new file mode 100644 index 000000000000..3a5b0fcbaf1f --- /dev/null +++ b/arch/arm/mach-pxa/mfp-pxa3xx.c @@ -0,0 +1,255 @@ +/* + * linux/arch/arm/mach-pxa/mfp.c + * + * PXA3xx 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 <linux/sysdev.h> + +#include <asm/hardware.h> +#include <asm/arch/mfp.h> +#include <asm/arch/mfp-pxa3xx.h> +#include <asm/arch/pxa3xx-regs.h> + +/* 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 = (void __iomem *)&__REG(MFPR_BASE); + +struct pxa3xx_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 pxa3xx_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, +}; + +/* 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, +}; + +/* 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 MFPR register to make sure the + * previous writings are finished + */ +#define mfpr_sync() (void)__raw_readl(mfpr_mmio_base + 0) + +static inline void __mfp_config_run(struct pxa3xx_mfp_pin *p) +{ + if (mfp_configured(p)) + mfpr_writel(p->mfpr_off, p->mfpr_run); +} + +static inline void __mfp_config_lpm(struct pxa3xx_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 pxa3xx_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 pxa3xx_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 pxa3xx_mfp_read(int mfp) +{ + unsigned long val, flags; + + BUG_ON(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 pxa3xx_mfp_write(int mfp, unsigned long val) +{ + unsigned long flags; + + BUG_ON(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 pxa3xx_mfp_init_addr(struct pxa3xx_mfp_addr_map *map) +{ + struct pxa3xx_mfp_addr_map *p; + unsigned long offset, flags; + int i; + + spin_lock_irqsave(&mfp_spin_lock, flags); + + 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 __init pxa3xx_init_mfp(void) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(mfp_table); i++) + mfp_table[i].config = -1; +} + +#ifdef CONFIG_PM +/* + * Configure the MFPs appropriately for suspend/resume. + * FIXME: this should probably depend on which system state we're + * entering - for instance, we might not want to place MFP pins in + * a pull-down mode if they're an active low chip select, and we're + * just entering standby. + */ +static int pxa3xx_mfp_suspend(struct sys_device *d, pm_message_t state) +{ + int pin; + + for (pin = 0; pin < ARRAY_SIZE(mfp_table); pin++) { + struct pxa3xx_mfp_pin *p = &mfp_table[pin]; + __mfp_config_lpm(p); + } + return 0; +} + +static int pxa3xx_mfp_resume(struct sys_device *d) +{ + int pin; + + for (pin = 0; pin < ARRAY_SIZE(mfp_table); pin++) { + struct pxa3xx_mfp_pin *p = &mfp_table[pin]; + __mfp_config_run(p); + } + + /* clear RDH bit when MFP settings are restored + * + * NOTE: the last 3 bits DxS are write-1-to-clear so carefully + * preserve them here in case they will be referenced later + */ + ASCR &= ~(ASCR_RDH | ASCR_D1S | ASCR_D2S | ASCR_D3S); + + return 0; +} +#else +#define pxa3xx_mfp_suspend NULL +#define pxa3xx_mfp_resume NULL +#endif + +struct sysdev_class pxa3xx_mfp_sysclass = { + .name = "mfp", + .suspend = pxa3xx_mfp_suspend, + .resume = pxa3xx_mfp_resume, +}; + +static int __init mfp_init_devicefs(void) +{ + if (cpu_is_pxa3xx()) + return sysdev_class_register(&pxa3xx_mfp_sysclass); + + return 0; +} +postcore_initcall(mfp_init_devicefs); |