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authorJoshua Kinard <kumba@gentoo.org>2015-02-16 16:00:26 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2015-02-16 17:56:05 -0800
commitaaaf5fbf56f16c81a653713cc333b18ad6e25ea9 (patch)
tree5416188285df8877c1e069f3db9a24541c2b057f /include/linux/rtc
parentbefeb596a7224119b60499eb20c7545f7a73f104 (diff)
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.h375
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_ */