Pcf8653 driver

<pre> /*

* An I2C driver for the Philips PCF8563 RTC
* Copyright 2005-06 Tower Technologies
*
* Author: Alessandro Zummo <a.zummo@towertech.it>
* Maintainers: http://www.nslu2-linux.org/
*
* based on the other drivers in this same directory.
*
* http://www.semiconductors.philips.com/acrobat/datasheets/PCF8563-04.pdf
*
* 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.
*/

1. include <linux/clk-provider.h>
2. include <linux/i2c.h>
3. include <linux/bcd.h>
4. include <linux/rtc.h>
5. include <linux/slab.h>
6. include <linux/module.h>
7. include <linux/of.h>
8. include <linux/err.h>

1. define PCF8563_REG_ST1 0x00 /* status */
2. define PCF8563_REG_ST2 0x01
3. define PCF8563_BIT_AIE (1 << 1)
4. define PCF8563_BIT_AF (1 << 3)
5. define PCF8563_BITS_ST2_N (7 << 5)

1. define PCF8563_REG_SC 0x02 /* datetime */
2. define PCF8563_REG_MN 0x03
3. define PCF8563_REG_HR 0x04
4. define PCF8563_REG_DM 0x05
5. define PCF8563_REG_DW 0x06
6. define PCF8563_REG_MO 0x07
7. define PCF8563_REG_YR 0x08

1. define PCF8563_REG_AMN 0x09 /* alarm */

1. define PCF8563_REG_CLKO 0x0D /* clock out */
2. define PCF8563_REG_CLKO_FE 0x80 /* clock out enabled */
3. define PCF8563_REG_CLKO_F_MASK 0x03 /* frequenc mask */
4. define PCF8563_REG_CLKO_F_32768HZ 0x00
5. define PCF8563_REG_CLKO_F_1024HZ 0x01
6. define PCF8563_REG_CLKO_F_32HZ 0x02
7. define PCF8563_REG_CLKO_F_1HZ 0x03

1. define PCF8563_REG_TMRC 0x0E /* timer control */
2. define PCF8563_TMRC_ENABLE BIT(7)
3. define PCF8563_TMRC_4096 0
4. define PCF8563_TMRC_64 1
5. define PCF8563_TMRC_1 2
6. define PCF8563_TMRC_1_60 3
7. define PCF8563_TMRC_MASK 3

1. define PCF8563_REG_TMR 0x0F /* timer */

1. define PCF8563_SC_LV 0x80 /* low voltage */
2. define PCF8563_MO_C 0x80 /* century */

static struct i2c_driver pcf8563_driver;

struct pcf8563 { struct rtc_device *rtc; /* * The meaning of MO_C bit varies by the chip type. * From PCF8563 datasheet: this bit is toggled when the years * register overflows from 99 to 00 * 0 indicates the century is 20xx * 1 indicates the century is 19xx * From RTC8564 datasheet: this bit indicates change of * century. When the year digit data overflows from 99 to 00, * this bit is set. By presetting it to 0 while still in the * 20th century, it will be set in year 2000, ... * There seems no reliable way to know how the system use this * bit. So let's do it heuristically, assuming we are live in * 1970...2069. */ int c_polarity; /* 0: MO_C=1 means 19xx, otherwise MO_C=1 means 20xx */ int voltage_low; /* incicates if a low_voltage was detected */

struct i2c_client *client;

1. ifdef CONFIG_COMMON_CLK

struct clk_hw clkout_hw;

1. endif

};

static int pcf8563_read_block_data(struct i2c_client *client, unsigned char reg, unsigned char length, unsigned char *buf) { struct i2c_msg msgs[] = { {/* setup read ptr */ .addr = client->addr, .len = 1, .buf = &reg, }, { .addr = client->addr, .flags = I2C_M_RD, .len = length, .buf = buf }, };

if ((i2c_transfer(client->adapter, msgs, 2)) != 2) { dev_err(&client->dev, "%s: read error\n", __func__); return -EIO; }

return 0; }

static int pcf8563_write_block_data(struct i2c_client *client, unsigned char reg, unsigned char length, unsigned char *buf) { int i, err;

for (i = 0; i < length; i++) { unsigned char data[2] = { reg + i, buf[i] };

err = i2c_master_send(client, data, sizeof(data)); if (err != sizeof(data)) { dev_err(&client->dev, "%s: err=%d addr=%02x, data=%02x\n", __func__, err, data[0], data[1]); return -EIO; } }

return 0; }

static int pcf8563_set_alarm_mode(struct i2c_client *client, bool on) { unsigned char buf; int err;

err = pcf8563_read_block_data(client, PCF8563_REG_ST2, 1, &buf); if (err < 0) return err;

if (on) buf |= PCF8563_BIT_AIE; else buf &= ~PCF8563_BIT_AIE;

buf &= ~(PCF8563_BIT_AF | PCF8563_BITS_ST2_N);

err = pcf8563_write_block_data(client, PCF8563_REG_ST2, 1, &buf); if (err < 0) { dev_err(&client->dev, "%s: write error\n", __func__); return -EIO; }

return 0; }

static int pcf8563_get_alarm_mode(struct i2c_client *client, unsigned char *en, unsigned char *pen) { unsigned char buf; int err;

err = pcf8563_read_block_data(client, PCF8563_REG_ST2, 1, &buf); if (err) return err;

if (en) *en = !!(buf & PCF8563_BIT_AIE); if (pen) *pen = !!(buf & PCF8563_BIT_AF);

return 0; }

static irqreturn_t pcf8563_irq(int irq, void *dev_id) { struct pcf8563 *pcf8563 = i2c_get_clientdata(dev_id); int err; char pending;

err = pcf8563_get_alarm_mode(pcf8563->client, NULL, &pending); if (err) return IRQ_NONE;

if (pending) { rtc_update_irq(pcf8563->rtc, 1, RTC_IRQF | RTC_AF); pcf8563_set_alarm_mode(pcf8563->client, 1); return IRQ_HANDLED; }

return IRQ_NONE; }

/*

* In the routines that deal directly with the pcf8563 hardware, we use
* rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
*/

static int pcf8563_get_datetime(struct i2c_client *client, struct rtc_time *tm) { struct pcf8563 *pcf8563 = i2c_get_clientdata(client); unsigned char buf[9]; int err;

err = pcf8563_read_block_data(client, PCF8563_REG_ST1, 9, buf); if (err) return err;

if (buf[PCF8563_REG_SC] & PCF8563_SC_LV) { pcf8563->voltage_low = 1; dev_err(&client->dev, "low voltage detected, date/time is not reliable.\n"); return -EINVAL; }

dev_dbg(&client->dev, "%s: raw data is st1=%02x, st2=%02x, sec=%02x, min=%02x, hr=%02x, " "mday=%02x, wday=%02x, mon=%02x, year=%02x\n", __func__, buf[0], buf[1], buf[2], buf[3], buf[4], buf[5], buf[6], buf[7], buf[8]);

tm->tm_sec = bcd2bin(buf[PCF8563_REG_SC] & 0x7F); tm->tm_min = bcd2bin(buf[PCF8563_REG_MN] & 0x7F); tm->tm_hour = bcd2bin(buf[PCF8563_REG_HR] & 0x3F); /* rtc hr 0-23 */ tm->tm_mday = bcd2bin(buf[PCF8563_REG_DM] & 0x3F); tm->tm_wday = buf[PCF8563_REG_DW] & 0x07; tm->tm_mon = bcd2bin(buf[PCF8563_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */ tm->tm_year = bcd2bin(buf[PCF8563_REG_YR]); if (tm->tm_year < 70) tm->tm_year += 100; /* assume we are in 1970...2069 */ /* detect the polarity heuristically. see note above. */ pcf8563->c_polarity = (buf[PCF8563_REG_MO] & PCF8563_MO_C) ? (tm->tm_year >= 100) : (tm->tm_year < 100);

dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, " "mday=%d, mon=%d, year=%d, wday=%d\n", __func__, tm->tm_sec, tm->tm_min, tm->tm_hour, tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);

return 0; }

static int pcf8563_set_datetime(struct i2c_client *client, struct rtc_time *tm) { struct pcf8563 *pcf8563 = i2c_get_clientdata(client); unsigned char buf[9];

dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, " "mday=%d, mon=%d, year=%d, wday=%d\n", __func__, tm->tm_sec, tm->tm_min, tm->tm_hour, tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);

/* hours, minutes and seconds */ buf[PCF8563_REG_SC] = bin2bcd(tm->tm_sec); buf[PCF8563_REG_MN] = bin2bcd(tm->tm_min); buf[PCF8563_REG_HR] = bin2bcd(tm->tm_hour);

buf[PCF8563_REG_DM] = bin2bcd(tm->tm_mday);

/* month, 1 - 12 */ buf[PCF8563_REG_MO] = bin2bcd(tm->tm_mon + 1);

/* year and century */ buf[PCF8563_REG_YR] = bin2bcd(tm->tm_year % 100); if (pcf8563->c_polarity ? (tm->tm_year >= 100) : (tm->tm_year < 100)) buf[PCF8563_REG_MO] |= PCF8563_MO_C;

buf[PCF8563_REG_DW] = tm->tm_wday & 0x07;

return pcf8563_write_block_data(client, PCF8563_REG_SC, 9 - PCF8563_REG_SC, buf + PCF8563_REG_SC); }

1. ifdef CONFIG_RTC_INTF_DEV

static int pcf8563_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg) { struct pcf8563 *pcf8563 = i2c_get_clientdata(to_i2c_client(dev)); struct rtc_time tm;

switch (cmd) { case RTC_VL_READ: if (pcf8563->voltage_low) dev_info(dev, "low voltage detected, date/time is not reliable.\n");

if (copy_to_user((void __user *)arg, &pcf8563->voltage_low, sizeof(int))) return -EFAULT; return 0; case RTC_VL_CLR: /* * Clear the VL bit in the seconds register in case * the time has not been set already (which would * have cleared it). This does not really matter * because of the cached voltage_low value but do it * anyway for consistency. */ if (pcf8563_get_datetime(to_i2c_client(dev), &tm)) pcf8563_set_datetime(to_i2c_client(dev), &tm);

/* Clear the cached value. */ pcf8563->voltage_low = 0;

return 0; default: return -ENOIOCTLCMD; } }

1. else
2. define pcf8563_rtc_ioctl NULL
3. endif

static int pcf8563_rtc_read_time(struct device *dev, struct rtc_time *tm) { return pcf8563_get_datetime(to_i2c_client(dev), tm); }

static int pcf8563_rtc_set_time(struct device *dev, struct rtc_time *tm) { return pcf8563_set_datetime(to_i2c_client(dev), tm); }

static int pcf8563_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *tm) { struct i2c_client *client = to_i2c_client(dev); unsigned char buf[4]; int err;

err = pcf8563_read_block_data(client, PCF8563_REG_AMN, 4, buf); if (err) return err;

dev_dbg(&client->dev, "%s: raw data is min=%02x, hr=%02x, mday=%02x, wday=%02x\n", __func__, buf[0], buf[1], buf[2], buf[3]);

tm->time.tm_min = bcd2bin(buf[0] & 0x7F); tm->time.tm_hour = bcd2bin(buf[1] & 0x3F); tm->time.tm_mday = bcd2bin(buf[2] & 0x3F); tm->time.tm_wday = bcd2bin(buf[3] & 0x7); tm->time.tm_mon = -1; tm->time.tm_year = -1; tm->time.tm_yday = -1; tm->time.tm_isdst = -1;

err = pcf8563_get_alarm_mode(client, &tm->enabled, &tm->pending); if (err < 0) return err;

dev_dbg(&client->dev, "%s: tm is mins=%d, hours=%d, mday=%d, wday=%d," " enabled=%d, pending=%d\n", __func__, tm->time.tm_min, tm->time.tm_hour, tm->time.tm_mday, tm->time.tm_wday, tm->enabled, tm->pending);

return 0; }

static int pcf8563_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *tm) { struct i2c_client *client = to_i2c_client(dev); unsigned char buf[4]; int err;

/* The alarm has no seconds, round up to nearest minute */ if (tm->time.tm_sec) { time64_t alarm_time = rtc_tm_to_time64(&tm->time);

alarm_time += 60 - tm->time.tm_sec; rtc_time64_to_tm(alarm_time, &tm->time); }

dev_dbg(dev, "%s, min=%d hour=%d wday=%d mday=%d " "enabled=%d pending=%d\n", __func__, tm->time.tm_min, tm->time.tm_hour, tm->time.tm_wday, tm->time.tm_mday, tm->enabled, tm->pending);

buf[0] = bin2bcd(tm->time.tm_min); buf[1] = bin2bcd(tm->time.tm_hour); buf[2] = bin2bcd(tm->time.tm_mday); buf[3] = tm->time.tm_wday & 0x07;

err = pcf8563_write_block_data(client, PCF8563_REG_AMN, 4, buf); if (err) return err;

return pcf8563_set_alarm_mode(client, 1); }

static int pcf8563_irq_enable(struct device *dev, unsigned int enabled) { dev_dbg(dev, "%s: en=%d\n", __func__, enabled); return pcf8563_set_alarm_mode(to_i2c_client(dev), !!enabled); }

1. ifdef CONFIG_COMMON_CLK

/*

* Handling of the clkout
*/

1. define clkout_hw_to_pcf8563(_hw) container_of(_hw, struct pcf8563, clkout_hw)

static int clkout_rates[] = { 32768, 1024, 32, 1, };

static unsigned long pcf8563_clkout_recalc_rate(struct clk_hw *hw, unsigned long parent_rate) { struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw); struct i2c_client *client = pcf8563->client; unsigned char buf; int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);

if (ret < 0) return 0;

buf &= PCF8563_REG_CLKO_F_MASK; return clkout_rates[ret]; }

static long pcf8563_clkout_round_rate(struct clk_hw *hw, unsigned long rate, unsigned long *prate) { int i;

for (i = 0; i < ARRAY_SIZE(clkout_rates); i++) if (clkout_rates[i] <= rate) return clkout_rates[i];

return 0; }

static int pcf8563_clkout_set_rate(struct clk_hw *hw, unsigned long rate, unsigned long parent_rate) { struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw); struct i2c_client *client = pcf8563->client; unsigned char buf; int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf); int i;

if (ret < 0) return ret;

for (i = 0; i < ARRAY_SIZE(clkout_rates); i++) if (clkout_rates[i] == rate) { buf &= ~PCF8563_REG_CLKO_F_MASK; buf |= i; ret = pcf8563_write_block_data(client, PCF8563_REG_CLKO, 1, &buf); return ret; }

return -EINVAL; }

static int pcf8563_clkout_control(struct clk_hw *hw, bool enable) { struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw); struct i2c_client *client = pcf8563->client; unsigned char buf; int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);

if (ret < 0) return ret;

if (enable) buf |= PCF8563_REG_CLKO_FE; else buf &= ~PCF8563_REG_CLKO_FE;

ret = pcf8563_write_block_data(client, PCF8563_REG_CLKO, 1, &buf); return ret; }

static int pcf8563_clkout_prepare(struct clk_hw *hw) { return pcf8563_clkout_control(hw, 1); }

static void pcf8563_clkout_unprepare(struct clk_hw *hw) { pcf8563_clkout_control(hw, 0); }

static int pcf8563_clkout_is_prepared(struct clk_hw *hw) { struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw); struct i2c_client *client = pcf8563->client; unsigned char buf; int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);

if (ret < 0) return ret;

return !!(buf & PCF8563_REG_CLKO_FE); }

static const struct clk_ops pcf8563_clkout_ops = { .prepare = pcf8563_clkout_prepare, .unprepare = pcf8563_clkout_unprepare, .is_prepared = pcf8563_clkout_is_prepared, .recalc_rate = pcf8563_clkout_recalc_rate, .round_rate = pcf8563_clkout_round_rate, .set_rate = pcf8563_clkout_set_rate, };

static struct clk *pcf8563_clkout_register_clk(struct pcf8563 *pcf8563) { struct i2c_client *client = pcf8563->client; struct device_node *node = client->dev.of_node; struct clk *clk; struct clk_init_data init; int ret; unsigned char buf;

/* disable the clkout output */ buf = 0; ret = pcf8563_write_block_data(client, PCF8563_REG_CLKO, 1, &buf); if (ret < 0) return ERR_PTR(ret);

init.name = "pcf8563-clkout"; init.ops = &pcf8563_clkout_ops; init.flags = 0; init.parent_names = NULL; init.num_parents = 0; pcf8563->clkout_hw.init = &init;

/* optional override of the clockname */ of_property_read_string(node, "clock-output-names", &init.name);

/* register the clock */ clk = devm_clk_register(&client->dev, &pcf8563->clkout_hw);

if (!IS_ERR(clk)) of_clk_add_provider(node, of_clk_src_simple_get, clk);

return clk; }

1. endif

static const struct rtc_class_ops pcf8563_rtc_ops = { .ioctl = pcf8563_rtc_ioctl, .read_time = pcf8563_rtc_read_time, .set_time = pcf8563_rtc_set_time, .read_alarm = pcf8563_rtc_read_alarm, .set_alarm = pcf8563_rtc_set_alarm, .alarm_irq_enable = pcf8563_irq_enable, };

static int pcf8563_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct pcf8563 *pcf8563; int err; unsigned char buf; unsigned char alm_pending;

dev_dbg(&client->dev, "%s\n", __func__);

if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) return -ENODEV;

pcf8563 = devm_kzalloc(&client->dev, sizeof(struct pcf8563), GFP_KERNEL); if (!pcf8563) return -ENOMEM;

i2c_set_clientdata(client, pcf8563); pcf8563->client = client; device_set_wakeup_capable(&client->dev, 1);

/* Set timer to lowest frequency to save power (ref Haoyu datasheet) */ buf = PCF8563_TMRC_1_60; err = pcf8563_write_block_data(client, PCF8563_REG_TMRC, 1, &buf); if (err < 0) { dev_err(&client->dev, "%s: write error\n", __func__); return err; }

err = pcf8563_get_alarm_mode(client, NULL, &alm_pending); if (err) { dev_err(&client->dev, "%s: read error\n", __func__); return err; } if (alm_pending) pcf8563_set_alarm_mode(client, 0);

pcf8563->rtc = devm_rtc_device_register(&client->dev, pcf8563_driver.driver.name, &pcf8563_rtc_ops, THIS_MODULE);

if (IS_ERR(pcf8563->rtc)) return PTR_ERR(pcf8563->rtc);

if (client->irq > 0) { err = devm_request_threaded_irq(&client->dev, client->irq, NULL, pcf8563_irq, IRQF_SHARED|IRQF_ONESHOT|IRQF_TRIGGER_FALLING, pcf8563->rtc->name, client); if (err) { dev_err(&client->dev, "unable to request IRQ %d\n", client->irq); return err; }

}

1. ifdef CONFIG_COMMON_CLK

/* register clk in common clk framework */ pcf8563_clkout_register_clk(pcf8563);

1. endif

/* the pcf8563 alarm only supports a minute accuracy */ pcf8563->rtc->uie_unsupported = 1;

return 0; }

static const struct i2c_device_id pcf8563_id[] = { { "pcf8563", 0 }, { "rtc8564", 0 }, { } }; MODULE_DEVICE_TABLE(i2c, pcf8563_id);

1. ifdef CONFIG_OF

static const struct of_device_id pcf8563_of_match[] = { { .compatible = "nxp,pcf8563" }, {} }; MODULE_DEVICE_TABLE(of, pcf8563_of_match);

1. endif

static struct i2c_driver pcf8563_driver = { .driver = { .name = "rtc-pcf8563", .of_match_table = of_match_ptr(pcf8563_of_match), }, .probe = pcf8563_probe, .id_table = pcf8563_id, };

module_i2c_driver(pcf8563_driver);

MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>"); MODULE_DESCRIPTION("Philips PCF8563/Epson RTC8564 RTC driver"); MODULE_LICENSE("GPL"); </pre>