diff options
author | Joshua Kinard <kumba@gentoo.org> | 2015-02-17 03:00:26 +0300 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-02-17 04:56:05 +0300 |
commit | aaaf5fbf56f16c81a653713cc333b18ad6e25ea9 (patch) | |
tree | 5416188285df8877c1e069f3db9a24541c2b057f /include/linux/rtc | |
parent | befeb596a7224119b60499eb20c7545f7a73f104 (diff) | |
download | linux-aaaf5fbf56f16c81a653713cc333b18ad6e25ea9.tar.xz |
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>
Diffstat (limited to 'include/linux/rtc')
-rw-r--r-- | include/linux/rtc/ds1685.h | 375 |
1 files changed, 375 insertions, 0 deletions
diff --git a/include/linux/rtc/ds1685.h b/include/linux/rtc/ds1685.h new file mode 100644 index 000000000000..e6337a56d741 --- /dev/null +++ b/include/linux/rtc/ds1685.h @@ -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_ */ |