rtc: add driver for DS1685 family of real time clocks

This adds a driver for the Dallas/Maxim DS1685-family of RTC chips.  It
supports the DS1685/DS1687, DS1688/DS1691, DS1689/DS1693, DS17285/DS17287,
DS17485/DS17487, and DS17885/DS17887 RTC chips.  These chips are commonly
found in SGI O2 and SGI Octane systems.  It was originally derived from a
driver patch submitted by Matthias Fuchs many years ago for use in
EPPC-405-UC modules, which also used these RTCs.  In addition to the
time-keeping functions, this RTC also handles the shutdown mechanism of
the O2 and Octane and acts as a partial NVRAM for the boot PROMS in these
systems.

Verified on both an SGI O2 and an SGI Octane.

Signed-off-by: Joshua Kinard <kumba@gentoo.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Joshua Kinard 2015-02-16 16:00:26 -08:00 committed by Linus Torvalds
parent befeb596a7
commit aaaf5fbf56
5 changed files with 2724 additions and 0 deletions

View File

@ -2963,6 +2963,12 @@ S: Supported
F: drivers/input/touchscreen/cyttsp*
F: include/linux/input/cyttsp.h
DALLAS/MAXIM DS1685-FAMILY REAL TIME CLOCK
M: Joshua Kinard <kumba@gentoo.org>
S: Maintained
F: drivers/rtc/rtc-ds1685.c
F: include/linux/rtc/ds1685.h
DAMA SLAVE for AX.25
M: Joerg Reuter <jreuter@yaina.de>
W: http://yaina.de/jreuter/

View File

@ -801,6 +801,96 @@ config RTC_DRV_DS1553
This driver can also be built as a module. If so, the module
will be called rtc-ds1553.
config RTC_DRV_DS1685_FAMILY
tristate "Dallas/Maxim DS1685 Family"
help
If you say yes here you get support for the Dallas/Maxim DS1685
family of real time chips. This family includes the DS1685/DS1687,
DS1689/DS1693, DS17285/DS17287, DS17485/DS17487, and
DS17885/DS17887 chips.
This driver can also be built as a module. If so, the module
will be called rtc-ds1685.
choice
prompt "Subtype"
depends on RTC_DRV_DS1685_FAMILY
default RTC_DRV_DS1685
config RTC_DRV_DS1685
bool "DS1685/DS1687"
help
This enables support for the Dallas/Maxim DS1685/DS1687 real time
clock chip.
This chip is commonly found in SGI O2 (IP32) and SGI Octane (IP30)
systems, as well as EPPC-405-UC modules by electronic system design
GmbH.
config RTC_DRV_DS1689
bool "DS1689/DS1693"
help
This enables support for the Dallas/Maxim DS1689/DS1693 real time
clock chip.
This is an older RTC chip, supplanted by the DS1685/DS1687 above,
which supports a few minor features such as Vcc, Vbat, and Power
Cycle counters, plus a customer-specific, 8-byte ROM/Serial number.
It also works for the even older DS1688/DS1691 RTC chips, which are
virtually the same and carry the same model number. Both chips
have 114 bytes of user NVRAM.
config RTC_DRV_DS17285
bool "DS17285/DS17287"
help
This enables support for the Dallas/Maxim DS17285/DS17287 real time
clock chip.
This chip features 2kb of extended NV-SRAM. It may possibly be
found in some SGI O2 systems (rare).
config RTC_DRV_DS17485
bool "DS17485/DS17487"
help
This enables support for the Dallas/Maxim DS17485/DS17487 real time
clock chip.
This chip features 4kb of extended NV-SRAM.
config RTC_DRV_DS17885
bool "DS17885/DS17887"
help
This enables support for the Dallas/Maxim DS17885/DS17887 real time
clock chip.
This chip features 8kb of extended NV-SRAM.
endchoice
config RTC_DS1685_PROC_REGS
bool "Display register values in /proc"
depends on RTC_DRV_DS1685_FAMILY && PROC_FS
help
Enable this to display a readout of all of the RTC registers in
/proc/drivers/rtc. Keep in mind that this can potentially lead
to lost interrupts, as reading Control Register C will clear
all pending IRQ flags.
Unless you are debugging this driver, choose N.
config RTC_DS1685_SYSFS_REGS
bool "SysFS access to RTC register bits"
depends on RTC_DRV_DS1685_FAMILY && SYSFS
help
Enable this to provide access to the RTC control register bits
in /sys. Some of the bits are read-write, others are read-only.
Keep in mind that reading Control C's bits automatically clears
all pending IRQ flags - this can cause lost interrupts.
If you know that you need access to these bits, choose Y, Else N.
config RTC_DRV_DS1742
tristate "Maxim/Dallas DS1742/1743"
depends on HAS_IOMEM

View File

@ -54,6 +54,7 @@ obj-$(CONFIG_RTC_DRV_DS1390) += rtc-ds1390.o
obj-$(CONFIG_RTC_DRV_DS1511) += rtc-ds1511.o
obj-$(CONFIG_RTC_DRV_DS1553) += rtc-ds1553.o
obj-$(CONFIG_RTC_DRV_DS1672) += rtc-ds1672.o
obj-$(CONFIG_RTC_DRV_DS1685_FAMILY) += rtc-ds1685.o
obj-$(CONFIG_RTC_DRV_DS1742) += rtc-ds1742.o
obj-$(CONFIG_RTC_DRV_DS2404) += rtc-ds2404.o
obj-$(CONFIG_RTC_DRV_DS3232) += rtc-ds3232.o

2252
drivers/rtc/rtc-ds1685.c Normal file

File diff suppressed because it is too large Load Diff

375
include/linux/rtc/ds1685.h Normal file
View File

@ -0,0 +1,375 @@
/*
* Definitions for the registers, addresses, and platform data of the
* DS1685/DS1687-series RTC chips.
*
* This Driver also works for the DS17X85/DS17X87 RTC chips. Functionally
* similar to the DS1685/DS1687, they support a few extra features which
* include larger, battery-backed NV-SRAM, burst-mode access, and an RTC
* write counter.
*
* Copyright (C) 2011-2014 Joshua Kinard <kumba@gentoo.org>.
* Copyright (C) 2009 Matthias Fuchs <matthias.fuchs@esd-electronics.com>.
*
* References:
* DS1685/DS1687 3V/5V Real-Time Clocks, 19-5215, Rev 4/10.
* DS17x85/DS17x87 3V/5V Real-Time Clocks, 19-5222, Rev 4/10.
* DS1689/DS1693 3V/5V Serialized Real-Time Clocks, Rev 112105.
* Application Note 90, Using the Multiplex Bus RTC Extended Features.
*
* 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.
*/
#ifndef _LINUX_RTC_DS1685_H_
#define _LINUX_RTC_DS1685_H_
#include <linux/rtc.h>
#include <linux/platform_device.h>
#include <linux/workqueue.h>
/**
* struct ds1685_priv - DS1685 private data structure.
* @dev: pointer to the rtc_device structure.
* @regs: iomapped base address pointer of the RTC registers.
* @regstep: padding/step size between registers (optional).
* @baseaddr: base address of the RTC device.
* @size: resource size.
* @lock: private lock variable for spin locking/unlocking.
* @work: private workqueue.
* @irq: IRQ number assigned to the RTC device.
* @prepare_poweroff: pointer to platform pre-poweroff function.
* @wake_alarm: pointer to platform wake alarm function.
* @post_ram_clear: pointer to platform post ram-clear function.
*/
struct ds1685_priv {
struct rtc_device *dev;
void __iomem *regs;
u32 regstep;
resource_size_t baseaddr;
size_t size;
spinlock_t lock;
struct work_struct work;
int irq_num;
bool bcd_mode;
bool no_irq;
bool uie_unsupported;
bool alloc_io_resources;
u8 (*read)(struct ds1685_priv *, int);
void (*write)(struct ds1685_priv *, int, u8);
void (*prepare_poweroff)(void);
void (*wake_alarm)(void);
void (*post_ram_clear)(void);
};
/**
* struct ds1685_rtc_platform_data - platform data structure.
* @plat_prepare_poweroff: platform-specific pre-poweroff function.
* @plat_wake_alarm: platform-specific wake alarm function.
* @plat_post_ram_clear: platform-specific post ram-clear function.
*
* If your platform needs to use a custom padding/step size between
* registers, or uses one or more of the extended interrupts and needs special
* handling, then include this header file in your platform definition and
* set regstep and the plat_* pointers as appropriate.
*/
struct ds1685_rtc_platform_data {
const u32 regstep;
const bool bcd_mode;
const bool no_irq;
const bool uie_unsupported;
const bool alloc_io_resources;
u8 (*plat_read)(struct ds1685_priv *, int);
void (*plat_write)(struct ds1685_priv *, int, u8);
void (*plat_prepare_poweroff)(void);
void (*plat_wake_alarm)(void);
void (*plat_post_ram_clear)(void);
};
/*
* Time Registers.
*/
#define RTC_SECS 0x00 /* Seconds 00-59 */
#define RTC_SECS_ALARM 0x01 /* Alarm Seconds 00-59 */
#define RTC_MINS 0x02 /* Minutes 00-59 */
#define RTC_MINS_ALARM 0x03 /* Alarm Minutes 00-59 */
#define RTC_HRS 0x04 /* Hours 01-12 AM/PM || 00-23 */
#define RTC_HRS_ALARM 0x05 /* Alarm Hours 01-12 AM/PM || 00-23 */
#define RTC_WDAY 0x06 /* Day of Week 01-07 */
#define RTC_MDAY 0x07 /* Day of Month 01-31 */
#define RTC_MONTH 0x08 /* Month 01-12 */
#define RTC_YEAR 0x09 /* Year 00-99 */
#define RTC_CENTURY 0x48 /* Century 00-99 */
#define RTC_MDAY_ALARM 0x49 /* Alarm Day of Month 01-31 */
/*
* Bit masks for the Time registers in BCD Mode (DM = 0).
*/
#define RTC_SECS_BCD_MASK 0x7f /* - x x x x x x x */
#define RTC_MINS_BCD_MASK 0x7f /* - x x x x x x x */
#define RTC_HRS_12_BCD_MASK 0x1f /* - - - x x x x x */
#define RTC_HRS_24_BCD_MASK 0x3f /* - - x x x x x x */
#define RTC_MDAY_BCD_MASK 0x3f /* - - x x x x x x */
#define RTC_MONTH_BCD_MASK 0x1f /* - - - x x x x x */
#define RTC_YEAR_BCD_MASK 0xff /* x x x x x x x x */
/*
* Bit masks for the Time registers in BIN Mode (DM = 1).
*/
#define RTC_SECS_BIN_MASK 0x3f /* - - x x x x x x */
#define RTC_MINS_BIN_MASK 0x3f /* - - x x x x x x */
#define RTC_HRS_12_BIN_MASK 0x0f /* - - - - x x x x */
#define RTC_HRS_24_BIN_MASK 0x1f /* - - - x x x x x */
#define RTC_MDAY_BIN_MASK 0x1f /* - - - x x x x x */
#define RTC_MONTH_BIN_MASK 0x0f /* - - - - x x x x */
#define RTC_YEAR_BIN_MASK 0x7f /* - x x x x x x x */
/*
* Bit masks common for the Time registers in BCD or BIN Mode.
*/
#define RTC_WDAY_MASK 0x07 /* - - - - - x x x */
#define RTC_CENTURY_MASK 0xff /* x x x x x x x x */
#define RTC_MDAY_ALARM_MASK 0xff /* x x x x x x x x */
#define RTC_HRS_AMPM_MASK BIT(7) /* Mask for the AM/PM bit */
/*
* Control Registers.
*/
#define RTC_CTRL_A 0x0a /* Control Register A */
#define RTC_CTRL_B 0x0b /* Control Register B */
#define RTC_CTRL_C 0x0c /* Control Register C */
#define RTC_CTRL_D 0x0d /* Control Register D */
#define RTC_EXT_CTRL_4A 0x4a /* Extended Control Register 4A */
#define RTC_EXT_CTRL_4B 0x4b /* Extended Control Register 4B */
/*
* Bit names in Control Register A.
*/
#define RTC_CTRL_A_UIP BIT(7) /* Update In Progress */
#define RTC_CTRL_A_DV2 BIT(6) /* Countdown Chain */
#define RTC_CTRL_A_DV1 BIT(5) /* Oscillator Enable */
#define RTC_CTRL_A_DV0 BIT(4) /* Bank Select */
#define RTC_CTRL_A_RS2 BIT(2) /* Rate-Selection Bit 2 */
#define RTC_CTRL_A_RS3 BIT(3) /* Rate-Selection Bit 3 */
#define RTC_CTRL_A_RS1 BIT(1) /* Rate-Selection Bit 1 */
#define RTC_CTRL_A_RS0 BIT(0) /* Rate-Selection Bit 0 */
#define RTC_CTRL_A_RS_MASK 0x0f /* RS3 + RS2 + RS1 + RS0 */
/*
* Bit names in Control Register B.
*/
#define RTC_CTRL_B_SET BIT(7) /* SET Bit */
#define RTC_CTRL_B_PIE BIT(6) /* Periodic-Interrupt Enable */
#define RTC_CTRL_B_AIE BIT(5) /* Alarm-Interrupt Enable */
#define RTC_CTRL_B_UIE BIT(4) /* Update-Ended Interrupt-Enable */
#define RTC_CTRL_B_SQWE BIT(3) /* Square-Wave Enable */
#define RTC_CTRL_B_DM BIT(2) /* Data Mode */
#define RTC_CTRL_B_2412 BIT(1) /* 12-Hr/24-Hr Mode */
#define RTC_CTRL_B_DSE BIT(0) /* Daylight Savings Enable */
#define RTC_CTRL_B_PAU_MASK 0x70 /* PIE + AIE + UIE */
/*
* Bit names in Control Register C.
*
* BIT(0), BIT(1), BIT(2), & BIT(3) are unused, always return 0, and cannot
* be written to.
*/
#define RTC_CTRL_C_IRQF BIT(7) /* Interrupt-Request Flag */
#define RTC_CTRL_C_PF BIT(6) /* Periodic-Interrupt Flag */
#define RTC_CTRL_C_AF BIT(5) /* Alarm-Interrupt Flag */
#define RTC_CTRL_C_UF BIT(4) /* Update-Ended Interrupt Flag */
#define RTC_CTRL_C_PAU_MASK 0x70 /* PF + AF + UF */
/*
* Bit names in Control Register D.
*
* BIT(0) through BIT(6) are unused, always return 0, and cannot
* be written to.
*/
#define RTC_CTRL_D_VRT BIT(7) /* Valid RAM and Time */
/*
* Bit names in Extended Control Register 4A.
*
* On the DS1685/DS1687/DS1689/DS1693, BIT(4) and BIT(5) are reserved for
* future use. They can be read from and written to, but have no effect
* on the RTC's operation.
*
* On the DS17x85/DS17x87, BIT(5) is Burst-Mode Enable (BME), and allows
* access to the extended NV-SRAM by automatically incrementing the address
* register when they are read from or written to.
*/
#define RTC_CTRL_4A_VRT2 BIT(7) /* Auxillary Battery Status */
#define RTC_CTRL_4A_INCR BIT(6) /* Increment-in-Progress Status */
#define RTC_CTRL_4A_PAB BIT(3) /* Power-Active Bar Control */
#define RTC_CTRL_4A_RF BIT(2) /* RAM-Clear Flag */
#define RTC_CTRL_4A_WF BIT(1) /* Wake-Up Alarm Flag */
#define RTC_CTRL_4A_KF BIT(0) /* Kickstart Flag */
#if !defined(CONFIG_RTC_DRV_DS1685) && !defined(CONFIG_RTC_DRV_DS1689)
#define RTC_CTRL_4A_BME BIT(5) /* Burst-Mode Enable */
#endif
#define RTC_CTRL_4A_RWK_MASK 0x07 /* RF + WF + KF */
/*
* Bit names in Extended Control Register 4B.
*/
#define RTC_CTRL_4B_ABE BIT(7) /* Auxillary Battery Enable */
#define RTC_CTRL_4B_E32K BIT(6) /* Enable 32.768Hz on SQW Pin */
#define RTC_CTRL_4B_CS BIT(5) /* Crystal Select */
#define RTC_CTRL_4B_RCE BIT(4) /* RAM Clear-Enable */
#define RTC_CTRL_4B_PRS BIT(3) /* PAB Reset-Select */
#define RTC_CTRL_4B_RIE BIT(2) /* RAM Clear-Interrupt Enable */
#define RTC_CTRL_4B_WIE BIT(1) /* Wake-Up Alarm-Interrupt Enable */
#define RTC_CTRL_4B_KSE BIT(0) /* Kickstart Interrupt-Enable */
#define RTC_CTRL_4B_RWK_MASK 0x07 /* RIE + WIE + KSE */
/*
* Misc register names in Bank 1.
*
* The DV0 bit in Control Register A must be set to 1 for these registers
* to become available, including Extended Control Registers 4A & 4B.
*/
#define RTC_BANK1_SSN_MODEL 0x40 /* Model Number */
#define RTC_BANK1_SSN_BYTE_1 0x41 /* 1st Byte of Serial Number */
#define RTC_BANK1_SSN_BYTE_2 0x42 /* 2nd Byte of Serial Number */
#define RTC_BANK1_SSN_BYTE_3 0x43 /* 3rd Byte of Serial Number */
#define RTC_BANK1_SSN_BYTE_4 0x44 /* 4th Byte of Serial Number */
#define RTC_BANK1_SSN_BYTE_5 0x45 /* 5th Byte of Serial Number */
#define RTC_BANK1_SSN_BYTE_6 0x46 /* 6th Byte of Serial Number */
#define RTC_BANK1_SSN_CRC 0x47 /* Serial CRC Byte */
#define RTC_BANK1_RAM_DATA_PORT 0x53 /* Extended RAM Data Port */
/*
* Model-specific registers in Bank 1.
*
* The addresses below differ depending on the model of the RTC chip
* selected in the kernel configuration. Not all of these features are
* supported in the main driver at present.
*
* DS1685/DS1687 - Extended NV-SRAM address (LSB only).
* DS1689/DS1693 - Vcc, Vbat, Pwr Cycle Counters & Customer-specific S/N.
* DS17x85/DS17x87 - Extended NV-SRAM addresses (MSB & LSB) & Write counter.
*/
#if defined(CONFIG_RTC_DRV_DS1685)
#define RTC_BANK1_RAM_ADDR 0x50 /* NV-SRAM Addr */
#elif defined(CONFIG_RTC_DRV_DS1689)
#define RTC_BANK1_VCC_CTR_LSB 0x54 /* Vcc Counter Addr (LSB) */
#define RTC_BANK1_VCC_CTR_MSB 0x57 /* Vcc Counter Addr (MSB) */
#define RTC_BANK1_VBAT_CTR_LSB 0x58 /* Vbat Counter Addr (LSB) */
#define RTC_BANK1_VBAT_CTR_MSB 0x5b /* Vbat Counter Addr (MSB) */
#define RTC_BANK1_PWR_CTR_LSB 0x5c /* Pwr Cycle Counter Addr (LSB) */
#define RTC_BANK1_PWR_CTR_MSB 0x5d /* Pwr Cycle Counter Addr (MSB) */
#define RTC_BANK1_UNIQ_SN 0x60 /* Customer-specific S/N */
#else /* DS17x85/DS17x87 */
#define RTC_BANK1_RAM_ADDR_LSB 0x50 /* NV-SRAM Addr (LSB) */
#define RTC_BANK1_RAM_ADDR_MSB 0x51 /* NV-SRAM Addr (MSB) */
#define RTC_BANK1_WRITE_CTR 0x5e /* RTC Write Counter */
#endif
/*
* Model numbers.
*
* The DS1688/DS1691 and DS1689/DS1693 chips share the same model number
* and the manual doesn't indicate any major differences. As such, they
* are regarded as the same chip in this driver.
*/
#define RTC_MODEL_DS1685 0x71 /* DS1685/DS1687 */
#define RTC_MODEL_DS17285 0x72 /* DS17285/DS17287 */
#define RTC_MODEL_DS1689 0x73 /* DS1688/DS1691/DS1689/DS1693 */
#define RTC_MODEL_DS17485 0x74 /* DS17485/DS17487 */
#define RTC_MODEL_DS17885 0x78 /* DS17885/DS17887 */
/*
* Periodic Interrupt Rates / Square-Wave Output Frequency
*
* Periodic rates are selected by setting the RS3-RS0 bits in Control
* Register A and enabled via either the E32K bit in Extended Control
* Register 4B or the SQWE bit in Control Register B.
*
* E32K overrides the settings of RS3-RS0 and outputs a frequency of 32768Hz
* on the SQW pin of the RTC chip. While there are 16 possible selections,
* the 1-of-16 decoder is only able to divide the base 32768Hz signal into 13
* smaller frequencies. The values 0x01 and 0x02 are not used and are
* synonymous with 0x08 and 0x09, respectively.
*
* When E32K is set to a logic 1, periodic interrupts are disabled and reading
* /dev/rtc will return -EINVAL. This also applies if the periodic interrupt
* frequency is set to 0Hz.
*
* Not currently used by the rtc-ds1685 driver because the RTC core removed
* support for hardware-generated periodic-interrupts in favour of
* hrtimer-generated interrupts. But these defines are kept around for use
* in userland, as documentation to the hardware, and possible future use if
* hardware-generated periodic interrupts are ever added back.
*/
/* E32K RS3 RS2 RS1 RS0 */
#define RTC_SQW_8192HZ 0x03 /* 0 0 0 1 1 */
#define RTC_SQW_4096HZ 0x04 /* 0 0 1 0 0 */
#define RTC_SQW_2048HZ 0x05 /* 0 0 1 0 1 */
#define RTC_SQW_1024HZ 0x06 /* 0 0 1 1 0 */
#define RTC_SQW_512HZ 0x07 /* 0 0 1 1 1 */
#define RTC_SQW_256HZ 0x08 /* 0 1 0 0 0 */
#define RTC_SQW_128HZ 0x09 /* 0 1 0 0 1 */
#define RTC_SQW_64HZ 0x0a /* 0 1 0 1 0 */
#define RTC_SQW_32HZ 0x0b /* 0 1 0 1 1 */
#define RTC_SQW_16HZ 0x0c /* 0 1 1 0 0 */
#define RTC_SQW_8HZ 0x0d /* 0 1 1 0 1 */
#define RTC_SQW_4HZ 0x0e /* 0 1 1 1 0 */
#define RTC_SQW_2HZ 0x0f /* 0 1 1 1 1 */
#define RTC_SQW_0HZ 0x00 /* 0 0 0 0 0 */
#define RTC_SQW_32768HZ 32768 /* 1 - - - - */
#define RTC_MAX_USER_FREQ 8192
/*
* NVRAM data & addresses:
* - 50 bytes of NVRAM are available just past the clock registers.
* - 64 additional bytes are available in Bank0.
*
* Extended, battery-backed NV-SRAM:
* - DS1685/DS1687 - 128 bytes.
* - DS1689/DS1693 - 0 bytes.
* - DS17285/DS17287 - 2048 bytes.
* - DS17485/DS17487 - 4096 bytes.
* - DS17885/DS17887 - 8192 bytes.
*/
#define NVRAM_TIME_BASE 0x0e /* NVRAM Addr in Time regs */
#define NVRAM_BANK0_BASE 0x40 /* NVRAM Addr in Bank0 regs */
#define NVRAM_SZ_TIME 50
#define NVRAM_SZ_BANK0 64
#if defined(CONFIG_RTC_DRV_DS1685)
# define NVRAM_SZ_EXTND 128
#elif defined(CONFIG_RTC_DRV_DS1689)
# define NVRAM_SZ_EXTND 0
#elif defined(CONFIG_RTC_DRV_DS17285)
# define NVRAM_SZ_EXTND 2048
#elif defined(CONFIG_RTC_DRV_DS17485)
# define NVRAM_SZ_EXTND 4096
#elif defined(CONFIG_RTC_DRV_DS17885)
# define NVRAM_SZ_EXTND 8192
#endif
#define NVRAM_TOTAL_SZ_BANK0 (NVRAM_SZ_TIME + NVRAM_SZ_BANK0)
#define NVRAM_TOTAL_SZ (NVRAM_TOTAL_SZ_BANK0 + NVRAM_SZ_EXTND)
/*
* Function Prototypes.
*/
extern void __noreturn
ds1685_rtc_poweroff(struct platform_device *pdev);
#endif /* _LINUX_RTC_DS1685_H_ */