[RFC 1/5] ARM: at91: add general purpose backup register (GPBR) support
Jean-Christophe PLAGNIOL-VILLARD
plagnioj at jcrosoft.com
Mon Apr 8 03:33:29 EDT 2013
On 17:12 Sun 07 Apr , Johan Hovold wrote:
>
> Add General Purpose Backup Register (GPBR) support.
>
> Most at91 SoCs have at least four 32-bit General Purpose Backup
> Registers (GPBR) powered by backup-power (VDDBU). One such register is
> currently used by rtc-at91sam9 driver to store the RTC time base.
>
> Make sure the registers are mapped by arch setup code and add generic
> accessors for in-kernel use.
>
> This is a step in adding device-tree support to the rtc-at91sam9 driver.
>
This is a regression
we loose the tracking of what request and use the GPBR
Best Regsards,
J.
> Signed-off-by: Johan Hovold <jhovold at gmail.com>
> ---
> arch/arm/mach-at91/at91sam9260.c | 1 +
> arch/arm/mach-at91/at91sam9260_devices.c | 15 +++--------
> arch/arm/mach-at91/at91sam9261.c | 1 +
> arch/arm/mach-at91/at91sam9261_devices.c | 15 +++--------
> arch/arm/mach-at91/at91sam9263.c | 1 +
> arch/arm/mach-at91/at91sam9263_devices.c | 18 +++----------
> arch/arm/mach-at91/at91sam9g45.c | 1 +
> arch/arm/mach-at91/at91sam9g45_devices.c | 15 +++--------
> arch/arm/mach-at91/at91sam9rl.c | 1 +
> arch/arm/mach-at91/at91sam9rl_devices.c | 15 +++--------
> arch/arm/mach-at91/generic.h | 3 +++
> arch/arm/mach-at91/include/mach/at91_gpbr.h | 29 ++++++++++++++++++++
> arch/arm/mach-at91/setup.c | 10 +++++++
> drivers/rtc/rtc-at91sam9.c | 41 +++++++++--------------------
> 14 files changed, 76 insertions(+), 90 deletions(-)
> create mode 100644 arch/arm/mach-at91/include/mach/at91_gpbr.h
>
> diff --git a/arch/arm/mach-at91/at91sam9260.c b/arch/arm/mach-at91/at91sam9260.c
> index b67cd53..984b0d5 100644
> --- a/arch/arm/mach-at91/at91sam9260.c
> +++ b/arch/arm/mach-at91/at91sam9260.c
> @@ -334,6 +334,7 @@ static void __init at91sam9260_map_io(void)
>
> static void __init at91sam9260_ioremap_registers(void)
> {
> + at91_ioremap_gpbr(AT91SAM9260_BASE_GPBR, 0x10);
> at91_ioremap_shdwc(AT91SAM9260_BASE_SHDWC);
> at91_ioremap_rstc(AT91SAM9260_BASE_RSTC);
> at91_ioremap_ramc(0, AT91SAM9260_BASE_SDRAMC, 512);
> diff --git a/arch/arm/mach-at91/at91sam9260_devices.c b/arch/arm/mach-at91/at91sam9260_devices.c
> index eda8d16..10c71a8 100644
> --- a/arch/arm/mach-at91/at91sam9260_devices.c
> +++ b/arch/arm/mach-at91/at91sam9260_devices.c
> @@ -649,8 +649,6 @@ static struct resource rtt_resources[] = {
> .end = AT91SAM9260_BASE_RTT + SZ_16 - 1,
> .flags = IORESOURCE_MEM,
> }, {
> - .flags = IORESOURCE_MEM,
> - }, {
> .flags = IORESOURCE_IRQ,
> },
> };
> @@ -666,16 +664,9 @@ static struct platform_device at91sam9260_rtt_device = {
> static void __init at91_add_device_rtt_rtc(void)
> {
> at91sam9260_rtt_device.name = "rtc-at91sam9";
> - /*
> - * The second resource is needed:
> - * GPBR will serve as the storage for RTC time offset
> - */
> - at91sam9260_rtt_device.num_resources = 3;
> - rtt_resources[1].start = AT91SAM9260_BASE_GPBR +
> - 4 * CONFIG_RTC_DRV_AT91SAM9_GPBR;
> - rtt_resources[1].end = rtt_resources[1].start + 3;
> - rtt_resources[2].start = NR_IRQS_LEGACY + AT91_ID_SYS;
> - rtt_resources[2].end = NR_IRQS_LEGACY + AT91_ID_SYS;
> + at91sam9260_rtt_device.num_resources = 2;
> + rtt_resources[1].start = NR_IRQS_LEGACY + AT91_ID_SYS;
> + rtt_resources[1].end = NR_IRQS_LEGACY + AT91_ID_SYS;
> }
> #else
> static void __init at91_add_device_rtt_rtc(void)
> diff --git a/arch/arm/mach-at91/at91sam9261.c b/arch/arm/mach-at91/at91sam9261.c
> index 0204f4c..b234c5d 100644
> --- a/arch/arm/mach-at91/at91sam9261.c
> +++ b/arch/arm/mach-at91/at91sam9261.c
> @@ -278,6 +278,7 @@ static void __init at91sam9261_map_io(void)
>
> static void __init at91sam9261_ioremap_registers(void)
> {
> + at91_ioremap_gpbr(AT91SAM9261_BASE_GPBR, 0x10);
> at91_ioremap_shdwc(AT91SAM9261_BASE_SHDWC);
> at91_ioremap_rstc(AT91SAM9261_BASE_RSTC);
> at91_ioremap_ramc(0, AT91SAM9261_BASE_SDRAMC, 512);
> diff --git a/arch/arm/mach-at91/at91sam9261_devices.c b/arch/arm/mach-at91/at91sam9261_devices.c
> index 629ea5f..e8ff5e7 100644
> --- a/arch/arm/mach-at91/at91sam9261_devices.c
> +++ b/arch/arm/mach-at91/at91sam9261_devices.c
> @@ -618,8 +618,6 @@ static struct resource rtt_resources[] = {
> .end = AT91SAM9261_BASE_RTT + SZ_16 - 1,
> .flags = IORESOURCE_MEM,
> }, {
> - .flags = IORESOURCE_MEM,
> - }, {
> .flags = IORESOURCE_IRQ,
> }
> };
> @@ -634,16 +632,9 @@ static struct platform_device at91sam9261_rtt_device = {
> static void __init at91_add_device_rtt_rtc(void)
> {
> at91sam9261_rtt_device.name = "rtc-at91sam9";
> - /*
> - * The second resource is needed:
> - * GPBR will serve as the storage for RTC time offset
> - */
> - at91sam9261_rtt_device.num_resources = 3;
> - rtt_resources[1].start = AT91SAM9261_BASE_GPBR +
> - 4 * CONFIG_RTC_DRV_AT91SAM9_GPBR;
> - rtt_resources[1].end = rtt_resources[1].start + 3;
> - rtt_resources[2].start = NR_IRQS_LEGACY + AT91_ID_SYS;
> - rtt_resources[2].end = NR_IRQS_LEGACY + AT91_ID_SYS;
> + at91sam9261_rtt_device.num_resources = 2;
> + rtt_resources[1].start = NR_IRQS_LEGACY + AT91_ID_SYS;
> + rtt_resources[1].end = NR_IRQS_LEGACY + AT91_ID_SYS;
> }
> #else
> static void __init at91_add_device_rtt_rtc(void)
> diff --git a/arch/arm/mach-at91/at91sam9263.c b/arch/arm/mach-at91/at91sam9263.c
> index c0cbb81..42d09f5 100644
> --- a/arch/arm/mach-at91/at91sam9263.c
> +++ b/arch/arm/mach-at91/at91sam9263.c
> @@ -315,6 +315,7 @@ static void __init at91sam9263_map_io(void)
>
> static void __init at91sam9263_ioremap_registers(void)
> {
> + at91_ioremap_gpbr(AT91SAM9263_BASE_GPBR, 0x50);
> at91_ioremap_shdwc(AT91SAM9263_BASE_SHDWC);
> at91_ioremap_rstc(AT91SAM9263_BASE_RSTC);
> at91_ioremap_ramc(0, AT91SAM9263_BASE_SDRAMC0, 512);
> diff --git a/arch/arm/mach-at91/at91sam9263_devices.c b/arch/arm/mach-at91/at91sam9263_devices.c
> index 858c8aa..374fe56 100644
> --- a/arch/arm/mach-at91/at91sam9263_devices.c
> +++ b/arch/arm/mach-at91/at91sam9263_devices.c
> @@ -1014,8 +1014,6 @@ static struct resource rtt0_resources[] = {
> .end = AT91SAM9263_BASE_RTT0 + SZ_16 - 1,
> .flags = IORESOURCE_MEM,
> }, {
> - .flags = IORESOURCE_MEM,
> - }, {
> .flags = IORESOURCE_IRQ,
> }
> };
> @@ -1032,8 +1030,6 @@ static struct resource rtt1_resources[] = {
> .end = AT91SAM9263_BASE_RTT1 + SZ_16 - 1,
> .flags = IORESOURCE_MEM,
> }, {
> - .flags = IORESOURCE_MEM,
> - }, {
> .flags = IORESOURCE_IRQ,
> }
> };
> @@ -1052,18 +1048,14 @@ static void __init at91_add_device_rtt_rtc(void)
>
> switch (CONFIG_RTC_DRV_AT91SAM9_RTT) {
> case 0:
> - /*
> - * The second resource is needed only for the chosen RTT:
> - * GPBR will serve as the storage for RTC time offset
> - */
> - at91sam9263_rtt0_device.num_resources = 3;
> + at91sam9263_rtt0_device.num_resources = 2;
> at91sam9263_rtt1_device.num_resources = 1;
> pdev = &at91sam9263_rtt0_device;
> r = rtt0_resources;
> break;
> case 1:
> at91sam9263_rtt0_device.num_resources = 1;
> - at91sam9263_rtt1_device.num_resources = 3;
> + at91sam9263_rtt1_device.num_resources = 2;
> pdev = &at91sam9263_rtt1_device;
> r = rtt1_resources;
> break;
> @@ -1074,10 +1066,8 @@ static void __init at91_add_device_rtt_rtc(void)
> }
>
> pdev->name = "rtc-at91sam9";
> - r[1].start = AT91SAM9263_BASE_GPBR + 4 * CONFIG_RTC_DRV_AT91SAM9_GPBR;
> - r[1].end = r[1].start + 3;
> - r[2].start = NR_IRQS_LEGACY + AT91_ID_SYS;
> - r[2].end = NR_IRQS_LEGACY + AT91_ID_SYS;
> + r[1].start = NR_IRQS_LEGACY + AT91_ID_SYS;
> + r[1].end = NR_IRQS_LEGACY + AT91_ID_SYS;
> }
> #else
> static void __init at91_add_device_rtt_rtc(void)
> diff --git a/arch/arm/mach-at91/at91sam9g45.c b/arch/arm/mach-at91/at91sam9g45.c
> index b4968aa..4b9547f 100644
> --- a/arch/arm/mach-at91/at91sam9g45.c
> +++ b/arch/arm/mach-at91/at91sam9g45.c
> @@ -361,6 +361,7 @@ static void __init at91sam9g45_map_io(void)
>
> static void __init at91sam9g45_ioremap_registers(void)
> {
> + at91_ioremap_gpbr(AT91SAM9G45_BASE_GPBR, 0x10);
> at91_ioremap_shdwc(AT91SAM9G45_BASE_SHDWC);
> at91_ioremap_rstc(AT91SAM9G45_BASE_RSTC);
> at91_ioremap_ramc(0, AT91SAM9G45_BASE_DDRSDRC1, 512);
> diff --git a/arch/arm/mach-at91/at91sam9g45_devices.c b/arch/arm/mach-at91/at91sam9g45_devices.c
> index fe626d4..65d700b 100644
> --- a/arch/arm/mach-at91/at91sam9g45_devices.c
> +++ b/arch/arm/mach-at91/at91sam9g45_devices.c
> @@ -1290,8 +1290,6 @@ static struct resource rtt_resources[] = {
> .end = AT91SAM9G45_BASE_RTT + SZ_16 - 1,
> .flags = IORESOURCE_MEM,
> }, {
> - .flags = IORESOURCE_MEM,
> - }, {
> .flags = IORESOURCE_IRQ,
> }
> };
> @@ -1306,16 +1304,9 @@ static struct platform_device at91sam9g45_rtt_device = {
> static void __init at91_add_device_rtt_rtc(void)
> {
> at91sam9g45_rtt_device.name = "rtc-at91sam9";
> - /*
> - * The second resource is needed:
> - * GPBR will serve as the storage for RTC time offset
> - */
> - at91sam9g45_rtt_device.num_resources = 3;
> - rtt_resources[1].start = AT91SAM9G45_BASE_GPBR +
> - 4 * CONFIG_RTC_DRV_AT91SAM9_GPBR;
> - rtt_resources[1].end = rtt_resources[1].start + 3;
> - rtt_resources[2].start = NR_IRQS_LEGACY + AT91_ID_SYS;
> - rtt_resources[2].end = NR_IRQS_LEGACY + AT91_ID_SYS;
> + at91sam9g45_rtt_device.num_resources = 2;
> + rtt_resources[1].start = NR_IRQS_LEGACY + AT91_ID_SYS;
> + rtt_resources[1].end = NR_IRQS_LEGACY + AT91_ID_SYS;
> }
> #else
> static void __init at91_add_device_rtt_rtc(void)
> diff --git a/arch/arm/mach-at91/at91sam9rl.c b/arch/arm/mach-at91/at91sam9rl.c
> index 3de3e04..bf7e555 100644
> --- a/arch/arm/mach-at91/at91sam9rl.c
> +++ b/arch/arm/mach-at91/at91sam9rl.c
> @@ -281,6 +281,7 @@ static void __init at91sam9rl_map_io(void)
>
> static void __init at91sam9rl_ioremap_registers(void)
> {
> + at91_ioremap_gpbr(AT91SAM9RL_BASE_GPBR, 0x10);
> at91_ioremap_shdwc(AT91SAM9RL_BASE_SHDWC);
> at91_ioremap_rstc(AT91SAM9RL_BASE_RSTC);
> at91_ioremap_ramc(0, AT91SAM9RL_BASE_SDRAMC, 512);
> diff --git a/arch/arm/mach-at91/at91sam9rl_devices.c b/arch/arm/mach-at91/at91sam9rl_devices.c
> index 352468f..533948c 100644
> --- a/arch/arm/mach-at91/at91sam9rl_devices.c
> +++ b/arch/arm/mach-at91/at91sam9rl_devices.c
> @@ -687,8 +687,6 @@ static struct resource rtt_resources[] = {
> .end = AT91SAM9RL_BASE_RTT + SZ_16 - 1,
> .flags = IORESOURCE_MEM,
> }, {
> - .flags = IORESOURCE_MEM,
> - }, {
> .flags = IORESOURCE_IRQ,
> }
> };
> @@ -703,16 +701,9 @@ static struct platform_device at91sam9rl_rtt_device = {
> static void __init at91_add_device_rtt_rtc(void)
> {
> at91sam9rl_rtt_device.name = "rtc-at91sam9";
> - /*
> - * The second resource is needed:
> - * GPBR will serve as the storage for RTC time offset
> - */
> - at91sam9rl_rtt_device.num_resources = 3;
> - rtt_resources[1].start = AT91SAM9RL_BASE_GPBR +
> - 4 * CONFIG_RTC_DRV_AT91SAM9_GPBR;
> - rtt_resources[1].end = rtt_resources[1].start + 3;
> - rtt_resources[2].start = NR_IRQS_LEGACY + AT91_ID_SYS;
> - rtt_resources[2].end = NR_IRQS_LEGACY + AT91_ID_SYS;
> + at91sam9rl_rtt_device.num_resources = 2;
> + rtt_resources[1].start = NR_IRQS_LEGACY + AT91_ID_SYS;
> + rtt_resources[1].end = NR_IRQS_LEGACY + AT91_ID_SYS;
> }
> #else
> static void __init at91_add_device_rtt_rtc(void)
> diff --git a/arch/arm/mach-at91/generic.h b/arch/arm/mach-at91/generic.h
> index fc593d6..6d444cc 100644
> --- a/arch/arm/mach-at91/generic.h
> +++ b/arch/arm/mach-at91/generic.h
> @@ -59,6 +59,9 @@ extern void at91_irq_resume(void);
> /* idle */
> extern void at91sam9_idle(void);
>
> +/* backup registers */
> +extern void at91_ioremap_gpbr(u32 base_addr, u32 size);
> +
> /* reset */
> extern void at91_ioremap_rstc(u32 base_addr);
> extern void at91sam9_alt_restart(char, const char *);
> diff --git a/arch/arm/mach-at91/include/mach/at91_gpbr.h b/arch/arm/mach-at91/include/mach/at91_gpbr.h
> new file mode 100644
> index 0000000..f4b4895
> --- /dev/null
> +++ b/arch/arm/mach-at91/include/mach/at91_gpbr.h
> @@ -0,0 +1,29 @@
> +/*
> + * arch/arm/mach-at91/include/mach/at91_gpbr.h
> + *
> + * Copyright (C) 2013 Johan Hovold <jhovold at gmail.com>
> + *
> + * General Purpose Backup Registers (GPBR)
> + *
> + * 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.
> + */
> +
> +#ifndef AT91_GPBR_H
> +#define AT91_GPBR_H
> +
> +extern void __iomem *at91_gpbr_base;
> +
> +static inline u32 at91_gpbr_read(unsigned nr)
> +{
> + return __raw_readl(at91_gpbr_base + ((nr) << 2));
> +}
> +
> +static inline void at91_gpbr_write(unsigned nr, u32 value)
> +{
> + __raw_writel(value, at91_gpbr_base + ((nr) << 2));
> +}
> +
> +#endif /* AT91_GPBR_H */
> diff --git a/arch/arm/mach-at91/setup.c b/arch/arm/mach-at91/setup.c
> index 9e7c1e1..b01f4aa 100644
> --- a/arch/arm/mach-at91/setup.c
> +++ b/arch/arm/mach-at91/setup.c
> @@ -18,6 +18,7 @@
> #include <mach/hardware.h>
> #include <mach/cpu.h>
> #include <mach/at91_dbgu.h>
> +#include <mach/at91_gpbr.h>
> #include <mach/at91_pmc.h>
>
> #include "at91_shdwc.h"
> @@ -277,6 +278,15 @@ void __init at91_map_io(void)
> at91_boot_soc.map_io();
> }
>
> +void __iomem *at91_gpbr_base;
> +
> +void __init at91_ioremap_gpbr(u32 base_addr, u32 size)
> +{
> + at91_gpbr_base = ioremap(base_addr, size);
> + if (!at91_gpbr_base)
> + panic("AT91: Failed to ioremap gpbr registers\n");
> +}
> +
> void __iomem *at91_shdwc_base = NULL;
>
> static void at91sam9_poweroff(void)
> diff --git a/drivers/rtc/rtc-at91sam9.c b/drivers/rtc/rtc-at91sam9.c
> index 39cfd2e..983667b 100644
> --- a/drivers/rtc/rtc-at91sam9.c
> +++ b/drivers/rtc/rtc-at91sam9.c
> @@ -21,6 +21,7 @@
> #include <linux/slab.h>
> #include <linux/platform_data/atmel.h>
>
> +#include <mach/at91_gpbr.h>
> #include <mach/at91_rtt.h>
> #include <mach/cpu.h>
>
> @@ -57,7 +58,7 @@ struct sam9_rtc {
> void __iomem *rtt;
> struct rtc_device *rtcdev;
> u32 imr;
> - void __iomem *gpbr;
> + unsigned gpbr;
> int irq;
> };
>
> @@ -66,11 +67,6 @@ struct sam9_rtc {
> #define rtt_writel(rtc, field, val) \
> __raw_writel((val), (rtc)->rtt + AT91_RTT_ ## field)
>
> -#define gpbr_readl(rtc) \
> - __raw_readl((rtc)->gpbr)
> -#define gpbr_writel(rtc, val) \
> - __raw_writel((val), (rtc)->gpbr)
> -
> /*
> * Read current time and date in RTC
> */
> @@ -81,7 +77,7 @@ static int at91_rtc_readtime(struct device *dev, struct rtc_time *tm)
> u32 offset;
>
> /* read current time offset */
> - offset = gpbr_readl(rtc);
> + offset = at91_gpbr_read(rtc->gpbr);
> if (offset == 0)
> return -EILSEQ;
>
> @@ -124,11 +120,11 @@ static int at91_rtc_settime(struct device *dev, struct rtc_time *tm)
> rtt_writel(rtc, MR, mr & ~(AT91_RTT_ALMIEN | AT91_RTT_RTTINCIEN));
>
> /* read current time offset */
> - offset = gpbr_readl(rtc);
> + offset = at91_gpbr_read(rtc->gpbr);
>
> /* store the new base time in a battery backup register */
> secs += 1;
> - gpbr_writel(rtc, secs);
> + at91_gpbr_write(rtc->gpbr, secs);
>
> /* adjust the alarm time for the new base */
> alarm = rtt_readl(rtc, AR);
> @@ -160,7 +156,7 @@ static int at91_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
> u32 alarm = rtt_readl(rtc, AR);
> u32 offset;
>
> - offset = gpbr_readl(rtc);
> + offset = at91_gpbr_read(rtc->gpbr);
> if (offset == 0)
> return -EILSEQ;
>
> @@ -192,7 +188,7 @@ static int at91_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
> if (err != 0)
> return err;
>
> - offset = gpbr_readl(rtc);
> + offset = at91_gpbr_read(rtc->gpbr);
> if (offset == 0) {
> /* time is not set */
> return -EILSEQ;
> @@ -291,17 +287,14 @@ static const struct rtc_class_ops at91_rtc_ops = {
> */
> static int at91_rtc_probe(struct platform_device *pdev)
> {
> - struct resource *r, *r_gpbr;
> + struct resource *r;
> struct sam9_rtc *rtc;
> int ret, irq;
> u32 mr;
>
> r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> - r_gpbr = platform_get_resource(pdev, IORESOURCE_MEM, 1);
> - if (!r || !r_gpbr) {
> - dev_err(&pdev->dev, "need 2 ressources\n");
> - return -ENODEV;
> - }
> + if (!r)
> + return -ENXIO;
>
> irq = platform_get_irq(pdev, 0);
> if (irq < 0) {
> @@ -327,19 +320,14 @@ static int at91_rtc_probe(struct platform_device *pdev)
> goto fail;
> }
>
> - rtc->gpbr = ioremap(r_gpbr->start, resource_size(r_gpbr));
> - if (!rtc->gpbr) {
> - dev_err(&pdev->dev, "failed to map gpbr registers, aborting.\n");
> - ret = -ENOMEM;
> - goto fail_gpbr;
> - }
> + rtc->gpbr = CONFIG_RTC_DRV_AT91SAM9_GPBR;
>
> mr = rtt_readl(rtc, MR);
>
> /* unless RTT is counting at 1 Hz, re-initialize it */
> if ((mr & AT91_RTT_RTPRES) != AT91_SLOW_CLOCK) {
> mr = AT91_RTT_RTTRST | (AT91_SLOW_CLOCK & AT91_RTT_RTPRES);
> - gpbr_writel(rtc, 0);
> + at91_gpbr_write(rtc->gpbr, 0);
> }
>
> /* disable all interrupts (same as on shutdown path) */
> @@ -368,15 +356,13 @@ static int at91_rtc_probe(struct platform_device *pdev)
> * clock, discrete RTC, etc
> */
>
> - if (gpbr_readl(rtc) == 0)
> + if (at91_gpbr_read(rtc->gpbr) == 0)
> dev_warn(&pdev->dev, "%s: SET TIME!\n",
> dev_name(&rtc->rtcdev->dev));
>
> return 0;
>
> fail_register:
> - iounmap(rtc->gpbr);
> -fail_gpbr:
> iounmap(rtc->rtt);
> fail:
> platform_set_drvdata(pdev, NULL);
> @@ -398,7 +384,6 @@ static int at91_rtc_remove(struct platform_device *pdev)
>
> rtc_device_unregister(rtc->rtcdev);
>
> - iounmap(rtc->gpbr);
> iounmap(rtc->rtt);
> platform_set_drvdata(pdev, NULL);
> kfree(rtc);
> --
> 1.8.1.5
>
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