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author | root <root@artemis.panaceas.org> | 2015-12-25 04:40:36 +0000 |
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committer | root <root@artemis.panaceas.org> | 2015-12-25 04:40:36 +0000 |
commit | 849369d6c66d3054688672f97d31fceb8e8230fb (patch) | |
tree | 6135abc790ca67dedbe07c39806591e70eda81ce /arch/arm/mach-u300/padmux.c | |
download | linux-3.0.35-kobo-849369d6c66d3054688672f97d31fceb8e8230fb.tar.gz linux-3.0.35-kobo-849369d6c66d3054688672f97d31fceb8e8230fb.tar.bz2 linux-3.0.35-kobo-849369d6c66d3054688672f97d31fceb8e8230fb.zip |
initial_commit
Diffstat (limited to 'arch/arm/mach-u300/padmux.c')
-rw-r--r-- | arch/arm/mach-u300/padmux.c | 367 |
1 files changed, 367 insertions, 0 deletions
diff --git a/arch/arm/mach-u300/padmux.c b/arch/arm/mach-u300/padmux.c new file mode 100644 index 00000000..4c93c6ce --- /dev/null +++ b/arch/arm/mach-u300/padmux.c @@ -0,0 +1,367 @@ +/* + * + * arch/arm/mach-u300/padmux.c + * + * + * Copyright (C) 2009 ST-Ericsson AB + * License terms: GNU General Public License (GPL) version 2 + * U300 PADMUX functions + * Author: Martin Persson <martin.persson@stericsson.com> + */ + +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/device.h> +#include <linux/err.h> +#include <linux/errno.h> +#include <linux/io.h> +#include <linux/mutex.h> +#include <linux/string.h> +#include <linux/bug.h> +#include <linux/debugfs.h> +#include <linux/seq_file.h> +#include <mach/u300-regs.h> +#include <mach/syscon.h> +#include "padmux.h" + +static DEFINE_MUTEX(pmx_mutex); + +const u32 pmx_registers[] = { + (U300_SYSCON_VBASE + U300_SYSCON_PMC1LR), + (U300_SYSCON_VBASE + U300_SYSCON_PMC1HR), + (U300_SYSCON_VBASE + U300_SYSCON_PMC2R), + (U300_SYSCON_VBASE + U300_SYSCON_PMC3R), + (U300_SYSCON_VBASE + U300_SYSCON_PMC4R) +}; + +/* High level functionality */ + +/* Lazy dog: + * onmask = { + * {"PMC1LR" mask, "PMC1LR" value}, + * {"PMC1HR" mask, "PMC1HR" value}, + * {"PMC2R" mask, "PMC2R" value}, + * {"PMC3R" mask, "PMC3R" value}, + * {"PMC4R" mask, "PMC4R" value} + * } + */ +static struct pmx mmc_setting = { + .setting = U300_APP_PMX_MMC_SETTING, + .default_on = false, + .activated = false, + .name = "MMC", + .onmask = { + {U300_SYSCON_PMC1LR_MMCSD_MASK, + U300_SYSCON_PMC1LR_MMCSD_MMCSD}, + {0, 0}, + {0, 0}, + {0, 0}, + {U300_SYSCON_PMC4R_APP_MISC_12_MASK, + U300_SYSCON_PMC4R_APP_MISC_12_APP_GPIO} + }, +}; + +static struct pmx spi_setting = { + .setting = U300_APP_PMX_SPI_SETTING, + .default_on = false, + .activated = false, + .name = "SPI", + .onmask = {{0, 0}, + {U300_SYSCON_PMC1HR_APP_SPI_2_MASK | + U300_SYSCON_PMC1HR_APP_SPI_CS_1_MASK | + U300_SYSCON_PMC1HR_APP_SPI_CS_2_MASK, + U300_SYSCON_PMC1HR_APP_SPI_2_SPI | + U300_SYSCON_PMC1HR_APP_SPI_CS_1_SPI | + U300_SYSCON_PMC1HR_APP_SPI_CS_2_SPI}, + {0, 0}, + {0, 0}, + {0, 0} + }, +}; + +/* Available padmux settings */ +static struct pmx *pmx_settings[] = { + &mmc_setting, + &spi_setting, +}; + +static void update_registers(struct pmx *pmx, bool activate) +{ + u16 regval, val, mask; + int i; + + for (i = 0; i < ARRAY_SIZE(pmx_registers); i++) { + if (activate) + val = pmx->onmask[i].val; + else + val = 0; + + mask = pmx->onmask[i].mask; + if (mask != 0) { + regval = readw(pmx_registers[i]); + regval &= ~mask; + regval |= val; + writew(regval, pmx_registers[i]); + } + } +} + +struct pmx *pmx_get(struct device *dev, enum pmx_settings setting) +{ + int i; + struct pmx *pmx = ERR_PTR(-ENOENT); + + if (dev == NULL) + return ERR_PTR(-EINVAL); + + mutex_lock(&pmx_mutex); + for (i = 0; i < ARRAY_SIZE(pmx_settings); i++) { + + if (setting == pmx_settings[i]->setting) { + + if (pmx_settings[i]->dev != NULL) { + WARN(1, "padmux: required setting " + "in use by another consumer\n"); + } else { + pmx = pmx_settings[i]; + pmx->dev = dev; + dev_dbg(dev, "padmux: setting nr %d is now " + "bound to %s and ready to use\n", + setting, dev_name(dev)); + break; + } + } + } + mutex_unlock(&pmx_mutex); + + return pmx; +} +EXPORT_SYMBOL(pmx_get); + +int pmx_put(struct device *dev, struct pmx *pmx) +{ + int i; + int ret = -ENOENT; + + if (pmx == NULL || dev == NULL) + return -EINVAL; + + mutex_lock(&pmx_mutex); + for (i = 0; i < ARRAY_SIZE(pmx_settings); i++) { + + if (pmx->setting == pmx_settings[i]->setting) { + + if (dev != pmx->dev) { + WARN(1, "padmux: cannot release handle as " + "it is bound to another consumer\n"); + ret = -EINVAL; + break; + } else { + pmx_settings[i]->dev = NULL; + ret = 0; + break; + } + } + } + mutex_unlock(&pmx_mutex); + + return ret; +} +EXPORT_SYMBOL(pmx_put); + +int pmx_activate(struct device *dev, struct pmx *pmx) +{ + int i, j, ret; + ret = 0; + + if (pmx == NULL || dev == NULL) + return -EINVAL; + + mutex_lock(&pmx_mutex); + + /* Make sure the required bits are not used */ + for (i = 0; i < ARRAY_SIZE(pmx_settings); i++) { + + if (pmx_settings[i]->dev == NULL || pmx_settings[i] == pmx) + continue; + + for (j = 0; j < ARRAY_SIZE(pmx_registers); j++) { + + if (pmx_settings[i]->onmask[j].mask & pmx-> + onmask[j].mask) { + /* More than one entry on the same bits */ + WARN(1, "padmux: cannot activate " + "setting. Bit conflict with " + "an active setting\n"); + + ret = -EUSERS; + goto exit; + } + } + } + update_registers(pmx, true); + pmx->activated = true; + dev_dbg(dev, "padmux: setting nr %d is activated\n", + pmx->setting); + +exit: + mutex_unlock(&pmx_mutex); + return ret; +} +EXPORT_SYMBOL(pmx_activate); + +int pmx_deactivate(struct device *dev, struct pmx *pmx) +{ + int i; + int ret = -ENOENT; + + if (pmx == NULL || dev == NULL) + return -EINVAL; + + mutex_lock(&pmx_mutex); + for (i = 0; i < ARRAY_SIZE(pmx_settings); i++) { + + if (pmx_settings[i]->dev == NULL) + continue; + + if (pmx->setting == pmx_settings[i]->setting) { + + if (dev != pmx->dev) { + WARN(1, "padmux: cannot deactivate " + "pmx setting as it was activated " + "by another consumer\n"); + + ret = -EBUSY; + continue; + } else { + update_registers(pmx, false); + pmx_settings[i]->dev = NULL; + pmx->activated = false; + ret = 0; + dev_dbg(dev, "padmux: setting nr %d is deactivated", + pmx->setting); + break; + } + } + } + mutex_unlock(&pmx_mutex); + + return ret; +} +EXPORT_SYMBOL(pmx_deactivate); + +/* + * For internal use only. If it is to be exported, + * it should be reentrant. Notice that pmx_activate + * (i.e. runtime settings) always override default settings. + */ +static int pmx_set_default(void) +{ + /* Used to identify several entries on the same bits */ + u16 modbits[ARRAY_SIZE(pmx_registers)]; + + int i, j; + + memset(modbits, 0, ARRAY_SIZE(pmx_registers) * sizeof(u16)); + + for (i = 0; i < ARRAY_SIZE(pmx_settings); i++) { + + if (!pmx_settings[i]->default_on) + continue; + + for (j = 0; j < ARRAY_SIZE(pmx_registers); j++) { + + /* Make sure there is only one entry on the same bits */ + if (modbits[j] & pmx_settings[i]->onmask[j].mask) { + BUG(); + return -EUSERS; + } + modbits[j] |= pmx_settings[i]->onmask[j].mask; + } + update_registers(pmx_settings[i], true); + } + return 0; +} + +#if (defined(CONFIG_DEBUG_FS) && defined(CONFIG_U300_DEBUG)) +static int pmx_show(struct seq_file *s, void *data) +{ + int i; + seq_printf(s, "-------------------------------------------------\n"); + seq_printf(s, "SETTING BOUND TO DEVICE STATE\n"); + seq_printf(s, "-------------------------------------------------\n"); + mutex_lock(&pmx_mutex); + for (i = 0; i < ARRAY_SIZE(pmx_settings); i++) { + /* Format pmx and device name nicely */ + char cdp[33]; + int chars; + + chars = snprintf(&cdp[0], 17, "%s", pmx_settings[i]->name); + while (chars < 16) { + cdp[chars] = ' '; + chars++; + } + chars = snprintf(&cdp[16], 17, "%s", pmx_settings[i]->dev ? + dev_name(pmx_settings[i]->dev) : "N/A"); + while (chars < 16) { + cdp[chars+16] = ' '; + chars++; + } + cdp[32] = '\0'; + + seq_printf(s, + "%s\t%s\n", + &cdp[0], + pmx_settings[i]->activated ? + "ACTIVATED" : "DEACTIVATED" + ); + + } + mutex_unlock(&pmx_mutex); + return 0; +} + +static int pmx_open(struct inode *inode, struct file *file) +{ + return single_open(file, pmx_show, NULL); +} + +static const struct file_operations pmx_operations = { + .owner = THIS_MODULE, + .open = pmx_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +static int __init init_pmx_read_debugfs(void) +{ + /* Expose a simple debugfs interface to view pmx settings */ + (void) debugfs_create_file("padmux", S_IFREG | S_IRUGO, + NULL, NULL, + &pmx_operations); + return 0; +} + +/* + * This needs to come in after the core_initcall(), + * because debugfs is not available until + * the subsystems come up. + */ +module_init(init_pmx_read_debugfs); +#endif + +static int __init pmx_init(void) +{ + int ret; + + ret = pmx_set_default(); + + if (IS_ERR_VALUE(ret)) + pr_crit("padmux: default settings could not be set\n"); + + return 0; +} + +/* Should be initialized before consumers */ +core_initcall(pmx_init); |