From 2731b2eadeaa141e6f305fa8086106608112bbaa Mon Sep 17 00:00:00 2001 From: Roshni Shah Date: Mon, 14 Mar 2011 06:49:42 -0400 Subject: Add support for the i.MX53 QSB This patch seems to have originated from the 11.01.00 release from Freescale, which is no longer available except through the gitweb interface from Freescale. http://opensource.freescale.com/git?p=imx/linux-2.6-imx.git;a=commit;h=27fdf7bae11978d21e8aba09bb635f49b07edd4a --- drivers/misc/mxs-persistent.c | 271 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 271 insertions(+) create mode 100644 drivers/misc/mxs-persistent.c (limited to 'drivers/misc/mxs-persistent.c') diff --git a/drivers/misc/mxs-persistent.c b/drivers/misc/mxs-persistent.c new file mode 100644 index 000000000000..6acb006489d0 --- /dev/null +++ b/drivers/misc/mxs-persistent.c @@ -0,0 +1,271 @@ +/* + * Freescale STMP378X Persistent bits manipulation driver + * + * Author: Pantelis Antoniou + * + * Copyright 2008-2010 Freescale Semiconductor, Inc. + * Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved. + */ + +/* + * The code contained herein is licensed under the GNU General Public + * License. You may obtain a copy of the GNU General Public License + * Version 2 or later at the following locations: + * + * http://www.opensource.org/licenses/gpl-license.html + * http://www.gnu.org/copyleft/gpl.html + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +struct mxs_persistent_data { + struct device *dev; + struct mxs_platform_persistent_data *pdata; + int count; + struct attribute_group attr_group; + unsigned int base; + /* attribute ** follow */ + /* device_attribute follow */ +}; + +#define pd_attribute_ptr(x) \ + ((struct attribute **)((x) + 1)) +#define pd_device_attribute_ptr(x) \ + ((struct device_attribute *)(pd_attribute_ptr(x) + (x)->count + 1)) + +static inline u32 persistent_reg_read(struct mxs_persistent_data *pdata, + int reg) +{ + u32 msk; + + /* wait for stable value */ + msk = BF_RTC_STAT_STALE_REGS((0x1 << reg)); + while (__raw_readl(pdata->base + HW_RTC_STAT) & msk) + cpu_relax(); + + return __raw_readl(pdata->base + 0x60 + (reg * 0x10)); +} + +static inline void persistent_reg_wait_settle(struct mxs_persistent_data *pdata + , int reg) +{ + u32 msk; + + /* wait until the change is propagated */ + msk = BF_RTC_STAT_NEW_REGS((0x1 << reg)); + while (__raw_readl(pdata->base + HW_RTC_STAT) & msk) + cpu_relax(); +} + +static inline void persistent_reg_write(struct mxs_persistent_data *pdata, + u32 val, int reg) +{ + __raw_writel(val, pdata->base + 0x60 + (reg * 0x10)); + persistent_reg_wait_settle(pdata, reg); +} + +static inline void persistent_reg_set(struct mxs_persistent_data *pdata, + u32 val, int reg) +{ + __raw_writel(val, pdata->base + 0x60 + (reg * 0x10) + 0x4); + persistent_reg_wait_settle(pdata, reg); +} + +static inline void persistent_reg_clr(struct mxs_persistent_data *pdata, + u32 val, int reg) +{ + __raw_writel(val, pdata->base + 0x60 + (reg * 0x10) + 0x8); + persistent_reg_wait_settle(pdata, reg); +} + +static inline void persistent_reg_tog(struct mxs_persistent_data *pdata, + u32 val, int reg) +{ + __raw_writel(val, pdata->base + 0x60 + (reg * 0x10) + 0xc); + persistent_reg_wait_settle(pdata, reg); +} + +static ssize_t +persistent_show(struct device *dev, struct device_attribute *attr, char *buf) +{ + struct platform_device *pdev = to_platform_device(dev); + struct mxs_persistent_data *pd = platform_get_drvdata(pdev); + struct device_attribute *devattr = pd_device_attribute_ptr(pd); + const struct mxs_persistent_bit_config *pb; + int idx; + u32 val; + + idx = attr - devattr; + if ((unsigned int)idx >= pd->count) + return -EINVAL; + + pb = &pd->pdata->bit_config_tab[idx]; + + /* read value and shift */ + val = persistent_reg_read(pd, pb->reg); + val >>= pb->start; + val &= (1 << pb->width) - 1; + + return sprintf(buf, "%u\n", val); +} + +static ssize_t +persistent_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + struct platform_device *pdev = to_platform_device(dev); + struct mxs_persistent_data *pd = platform_get_drvdata(pdev); + struct device_attribute *devattr = pd_device_attribute_ptr(pd); + const struct mxs_persistent_bit_config *pb; + int idx, r; + unsigned long val, msk; + + idx = attr - devattr; + if ((unsigned int)idx >= pd->count) + return -EINVAL; + + pb = &pd->pdata->bit_config_tab[idx]; + + /* get value to write */ + r = strict_strtoul(buf, 10, &val); + if (r != 0) + return r; + + /* verify it fits */ + if ((unsigned int)val > (1 << pb->width) - 1) + return -EINVAL; + + /* lockless update, first clear the area */ + msk = ((1 << pb->width) - 1) << pb->start; + persistent_reg_clr(pd, msk, pb->reg); + + /* shift into position */ + val <<= pb->start; + persistent_reg_set(pd, val, pb->reg); + + return count; +} + + +static int __devinit mxs_persistent_probe(struct platform_device *pdev) +{ + struct mxs_persistent_data *pd; + struct mxs_platform_persistent_data *pdata; + struct resource *res; + const struct mxs_persistent_bit_config *pb; + struct attribute **attr; + struct device_attribute *devattr; + int i, cnt, size; + int err; + + pdata = pdev->dev.platform_data; + if (pdata == NULL) + return -ENODEV; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (res == NULL) + return -ENODEV; + + cnt = pdata->bit_config_cnt; + size = sizeof(*pd) + + (cnt + 1) * sizeof(struct atrribute *) + + cnt * sizeof(struct device_attribute); + pd = kzalloc(size, GFP_KERNEL); + if (pd == NULL) + return -ENOMEM; + pd->dev = &pdev->dev; + pd->pdata = pdata; + pd->base = (unsigned int)IO_ADDRESS(res->start); + + platform_set_drvdata(pdev, pd); + pd->count = cnt; + attr = pd_attribute_ptr(pd); + devattr = pd_device_attribute_ptr(pd); + + /* build the attributes structures */ + pd->attr_group.attrs = attr; + pb = pdata->bit_config_tab; + for (i = 0; i < cnt; i++) { + devattr[i].attr.name = pb[i].name; + devattr[i].attr.mode = S_IWUSR | S_IRUGO; + devattr[i].show = persistent_show; + devattr[i].store = persistent_store; + attr[i] = &devattr[i].attr; + } + + err = sysfs_create_group(&pdev->dev.kobj, &pd->attr_group); + if (err != 0) { + platform_set_drvdata(pdev, NULL); + kfree(pd); + return err; + } + + return 0; +} + +static int __devexit mxs_persistent_remove(struct platform_device *pdev) +{ + struct mxs_persistent_data *pd; + + pd = platform_get_drvdata(pdev); + sysfs_remove_group(&pdev->dev.kobj, &pd->attr_group); + platform_set_drvdata(pdev, NULL); + kfree(pd); + + return 0; +} + +#ifdef CONFIG_PM +static int +mxs_persistent_suspend(struct platform_device *pdev, pm_message_t state) +{ + return 0; +} + +static int mxs_persistent_resume(struct platform_device *pdev) +{ + return 0; +} +#else +#define mxs_persistent_suspend NULL +#define mxs_persistent_resume NULL +#endif + +static struct platform_driver mxs_persistent_driver = { + .probe = mxs_persistent_probe, + .remove = __exit_p(mxs_persistent_remove), + .suspend = mxs_persistent_suspend, + .resume = mxs_persistent_resume, + .driver = { + .name = "mxs-persistent", + .owner = THIS_MODULE, + }, +}; + +static int __init mxs_persistent_init(void) +{ + return platform_driver_register(&mxs_persistent_driver); +} + +static void __exit mxs_persistent_exit(void) +{ + platform_driver_unregister(&mxs_persistent_driver); +} + +MODULE_AUTHOR("Pantelis Antoniou "); +MODULE_DESCRIPTION("Persistent bits user-access driver"); +MODULE_LICENSE("GPL"); + +module_init(mxs_persistent_init); +module_exit(mxs_persistent_exit); -- cgit v1.2.3