hi, some comments inline
El Sun, Dec 04, 2011 at 10:45:21AM +0100 Heiko Schocher ha dit: > This driver implements the Linux kernel half of the boot count feature - > the boot counter can only be reset after it is clear that the > application has been started and is running correctly, which usually > can only be determined by the application code itself. Thus the reset > of the boot counter must be done by application code, which thus needs > an appropriate driver. > > Required feature by the Carrier Grade Linux Requirements Definition; > see for example document "Carrier Grade Linux Requirements Definition > Overview V3.0" at > > http://www.linuxfoundation.org/collaborate/workgroups/cgl/requirements#SMM.6.0_Boot_Cycle_Detection > > Description: OSDL CGL specifies that carrier grade Linux > shall provide support for detecting a repeating reboot cycle > due to recurring failures. This detection should happen in > user space before system services are started. > > This driver provides read/write access to the U-Boot bootcounter > through PROC FS and/or sysFS file. > > The bootcountregister gets configured via DTS. > for example on the enbw_cmc board: > > bootcount@0x23060 { > compatible = "uboot,bootcount"; > reg = <0x23060 0x20>; > }; > > original post from: > http://old.nabble.com/-POWERPC--add-U-Boot-bootcount-driver.-td26804029.html > > Signed-off-by: Heiko Schocher <[email protected]> > Cc: Wolfgang Denk <[email protected]> > Cc: Vitaly Bordug <[email protected]> > Cc: [email protected] > Cc: [email protected] > --- > .../devicetree/bindings/char/bootcount.txt | 13 ++ > drivers/char/Kconfig | 7 + > drivers/char/Makefile | 1 + > drivers/char/bootcount.c | 210 > ++++++++++++++++++++ > 4 files changed, 231 insertions(+), 0 deletions(-) > create mode 100644 Documentation/devicetree/bindings/char/bootcount.txt > create mode 100644 drivers/char/bootcount.c > > diff --git a/Documentation/devicetree/bindings/char/bootcount.txt > b/Documentation/devicetree/bindings/char/bootcount.txt > new file mode 100644 > index 0000000..079a7da > --- /dev/null > +++ b/Documentation/devicetree/bindings/char/bootcount.txt > @@ -0,0 +1,13 @@ > +Bootcount driver > + > +Required properties: > + > + - compatible : should be "uboot,bootcount" > + - reg: the address of the bootcounter > + > +Example: > + > +bootcount@1c23000 { > + compatible = "uboot,bootcount"; > + reg = <0x23060 0x20>; > +}; > diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig > index 4364303..9c5ccab 100644 > --- a/drivers/char/Kconfig > +++ b/drivers/char/Kconfig > @@ -577,6 +577,13 @@ config UV_MMTIMER > The uv_mmtimer device allows direct userspace access to the > UV system timer. > > +config BOOTCOUNT > + tristate "U-Boot Bootcount driver" > + depends on OF > + help > + The U-Boot Bootcount driver allows to access the > + bootcounter through procFS or sysFS files. > + > source "drivers/char/tpm/Kconfig" > > config TELCLOCK > diff --git a/drivers/char/Makefile b/drivers/char/Makefile > index 32762ba..a91e18e 100644 > --- a/drivers/char/Makefile > +++ b/drivers/char/Makefile > @@ -49,6 +49,7 @@ obj-$(CONFIG_PC8736x_GPIO) += pc8736x_gpio.o > obj-$(CONFIG_NSC_GPIO) += nsc_gpio.o > obj-$(CONFIG_GPIO_TB0219) += tb0219.o > obj-$(CONFIG_TELCLOCK) += tlclk.o > +obj-$(CONFIG_BOOTCOUNT) += bootcount.o > > obj-$(CONFIG_MWAVE) += mwave/ > obj-$(CONFIG_AGP) += agp/ > diff --git a/drivers/char/bootcount.c b/drivers/char/bootcount.c > new file mode 100644 > index 0000000..0ee457f > --- /dev/null > +++ b/drivers/char/bootcount.c > @@ -0,0 +1,210 @@ > +/* > + * This driver gives access(read/write) to the bootcounter used by u-boot. > + * Access is supported via procFS and sysFS. > + * > + * Copyright 2008 DENX Software Engineering GmbH > + * Author: Heiko Schocher <[email protected]> > + * Based on work from: Steffen Rumler ([email protected]) > + * > + * This program is free software; you can redistribute it and/or modify it > + * under the terms of the GNU General Public License as published by the > + * Free Software Foundation; either version 2 of the License, or (at your > + * option) any later version. > + */ > + > +#include <linux/capability.h> > +#include <linux/device.h> > +#include <linux/init.h> > +#include <linux/io.h> > +#include <linux/mm.h> > +#include <linux/mman.h> > +#include <linux/module.h> > +#include <linux/of.h> > +#include <linux/of_address.h> > +#include <linux/of_device.h> > +#include <linux/of_platform.h> > +#include <linux/ptrace.h> > +#include <linux/uaccess.h> > + > +#ifndef CONFIG_PROC_FS > +#error "PROC FS support must be switched-on" > +#endif > +#include <linux/proc_fs.h> > + > +#define UBOOT_BOOTCOUNT_MAGIC_OFFSET 0x04 /* offset of magic > number */ > +#define UBOOT_BOOTCOUNT_MAGIC 0xB001C041 /* magic number > value */ > + > +#define UBOOT_BOOTCOUNT_PROC_ENTRY "driver/bootcount" > + > +/* > + * This macro frees the machine specific function from bounds checking and > + * this like that... > + */ > +#define PRINT_PROC(fmt, args...) \ > + do { \ > + *len += sprintf(buffer + *len, fmt, ##args); \ > + if (*begin + *len > offset + size) \ > + return 0; \ > + if (*begin + *len < offset) { \ > + *begin += *len; \ > + *len = 0; \ > + } \ > + } while (0) > + > +void __iomem *mem; +static void __iomem *mem; > +/* > + * read U-Boot bootcounter > + */ > +static int > +read_bootcounter_info(char *buffer, int *len, off_t * begin, off_t offset, > + int size) > +{ > + unsigned long magic; > + unsigned long counter; > + > + remove second empty line > + magic = be32_to_cpu(readl(mem + UBOOT_BOOTCOUNT_MAGIC_OFFSET)); > + counter = be32_to_cpu(readl(mem)); > + > + if (magic == UBOOT_BOOTCOUNT_MAGIC) { > + PRINT_PROC("%lu\n", counter); > + } else { > + PRINT_PROC("bad magic: 0x%lu != 0x%lu\n", magic, > + (unsigned long)UBOOT_BOOTCOUNT_MAGIC); > + } no need for curly braces > + > + return 1; > +} > + > +/* > + * read U-Boot bootcounter (wrapper) > + */ > +static int > +read_bootcounter(char *buffer, char **start, off_t offset, int size, > + int *eof, void *arg) > +{ > + int len = 0; > + off_t begin = 0; > + > + remove second empty line > + *eof = read_bootcounter_info(buffer, &len, &begin, offset, size); > + > + if (offset >= begin + len) > + return 0; > + > + *start = buffer + (offset - begin); > + return size < begin + len - offset ? size : begin + len - offset; > +} > + > +/* > + * write new value to U-Boot bootcounter > + */ > +static int > +write_bootcounter(struct file *file, const char *buffer, unsigned long count, > + void *data) > +{ > + unsigned long magic; > + > + magic = be32_to_cpu(readl(mem + UBOOT_BOOTCOUNT_MAGIC_OFFSET)); > + if (magic == UBOOT_BOOTCOUNT_MAGIC) > + writel(cpu_to_be32(simple_strtol(buffer, NULL, 10)), mem); > + else > + return -EINVAL; > + > + return count; > +} > + > +/* helper for the sysFS */ > +static int show_str_bootcount(struct device *device, > + struct device_attribute *attr, > + char *buf) > +{ > + int ret = 0; > + off_t begin = 0; > + > + read_bootcounter_info(buf, &ret, &begin, 0, 20); > + return ret; > +} > +static int store_str_bootcount(struct device *dev, > + struct device_attribute *attr, > + const char *buf, > + size_t count) > +{ > + write_bootcounter(NULL, buf, count, NULL); > + return count; > +} > +static DEVICE_ATTR(bootcount, S_IWUSR | S_IRUGO, show_str_bootcount, > + store_str_bootcount); > + > +static int __devinit bootcount_probe(struct platform_device *ofdev) > +{ > + struct device_node *np = of_node_get(ofdev->dev.of_node); > + struct proc_dir_entry *bootcount; > + > + mem = of_iomap(np, 0); > + if (mem == NULL) > + dev_err(&ofdev->dev, "%s couldnt map register.\n", __func__); return -1; ? also applies to other error paths in this function. carrying on without the register mapped or without access to the bootcounter doesn't seem to make much sense > + > + /* init ProcFS */ > + bootcount = create_proc_entry(UBOOT_BOOTCOUNT_PROC_ENTRY, 0600, NULL); > + if (bootcount == NULL) { > + dev_err(&ofdev->dev, "\n%s (%d): cannot create /proc/%s\n", > + __FILE__, __LINE__, UBOOT_BOOTCOUNT_PROC_ENTRY); > + } else { > + > + bootcount->read_proc = read_bootcounter; > + bootcount->write_proc = write_bootcounter; > + dev_info(&ofdev->dev, "created \"/proc/%s\"\n", > + UBOOT_BOOTCOUNT_PROC_ENTRY); > + } > + > + if (device_create_file(&ofdev->dev, &dev_attr_bootcount)) > + dev_warn(&ofdev->dev, "%s couldnt register sysFS entry.\n", > + __func__); > + > + return 0; > +} > + > +static int __devexit bootcount_remove(struct platform_device *ofdev) > +{ > + BUG(); > + return 0; > +} > + > +static const struct of_device_id __devinitconst bootcount_match[] = { > + { > + .compatible = "uboot,bootcount", > + }, > + {}, > +}; > +MODULE_DEVICE_TABLE(of, bootcount_match); > + > +static struct platform_driver bootcount_driver = { > + .driver = { > + .name = "bootcount", > + .of_match_table = bootcount_match, > + .owner = THIS_MODULE, > + }, > + .probe = bootcount_probe, > + .remove = bootcount_remove, > +}; > + > + > +static int __init uboot_bootcount_init(void) > +{ > + return platform_driver_register(&bootcount_driver); > +} > + > +static void __exit uboot_bootcount_cleanup(void) > +{ > + if (mem != NULL) > + iounmap(mem); > + remove_proc_entry(UBOOT_BOOTCOUNT_PROC_ENTRY, NULL); > +} > + > +module_init(uboot_bootcount_init); > +module_exit(uboot_bootcount_cleanup); > + > +MODULE_LICENSE("GPL"); > +MODULE_AUTHOR("Steffen Rumler <[email protected]>"); > +MODULE_DESCRIPTION("Provide (read/write) access to the U-Boot bootcounter > via PROC FS"); -- Matthias Kaehlcke Embedded Linux Developer Amsterdam The opposite of love is not hate, it's indifference (Elie Wiesel) .''`. using free software / Debian GNU/Linux | http://debian.org : :' : `. `'` gpg --keyserver pgp.mit.edu --recv-keys 47D8E5D4 `- _______________________________________________ devicetree-discuss mailing list [email protected] https://lists.ozlabs.org/listinfo/devicetree-discuss
