diff options
Diffstat (limited to 'kernel/drivers/rtc/rtc-hym8563.c')
| -rw-r--r-- | kernel/drivers/rtc/rtc-hym8563.c | 612 |
1 files changed, 612 insertions, 0 deletions
diff --git a/kernel/drivers/rtc/rtc-hym8563.c b/kernel/drivers/rtc/rtc-hym8563.c new file mode 100644 index 000000000..0f710e985 --- /dev/null +++ b/kernel/drivers/rtc/rtc-hym8563.c @@ -0,0 +1,612 @@ +/* + * Haoyu HYM8563 RTC driver + * + * Copyright (C) 2013 MundoReader S.L. + * Author: Heiko Stuebner <heiko@sntech.de> + * + * based on rtc-HYM8563 + * Copyright (C) 2010 ROCKCHIP, Inc. + * + * This software is licensed under the terms of the GNU General Public + * License version 2, as published by the Free Software Foundation, and + * may be copied, distributed, and modified under those terms. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <linux/module.h> +#include <linux/clk-provider.h> +#include <linux/i2c.h> +#include <linux/bcd.h> +#include <linux/rtc.h> + +#define HYM8563_CTL1 0x00 +#define HYM8563_CTL1_TEST BIT(7) +#define HYM8563_CTL1_STOP BIT(5) +#define HYM8563_CTL1_TESTC BIT(3) + +#define HYM8563_CTL2 0x01 +#define HYM8563_CTL2_TI_TP BIT(4) +#define HYM8563_CTL2_AF BIT(3) +#define HYM8563_CTL2_TF BIT(2) +#define HYM8563_CTL2_AIE BIT(1) +#define HYM8563_CTL2_TIE BIT(0) + +#define HYM8563_SEC 0x02 +#define HYM8563_SEC_VL BIT(7) +#define HYM8563_SEC_MASK 0x7f + +#define HYM8563_MIN 0x03 +#define HYM8563_MIN_MASK 0x7f + +#define HYM8563_HOUR 0x04 +#define HYM8563_HOUR_MASK 0x3f + +#define HYM8563_DAY 0x05 +#define HYM8563_DAY_MASK 0x3f + +#define HYM8563_WEEKDAY 0x06 +#define HYM8563_WEEKDAY_MASK 0x07 + +#define HYM8563_MONTH 0x07 +#define HYM8563_MONTH_CENTURY BIT(7) +#define HYM8563_MONTH_MASK 0x1f + +#define HYM8563_YEAR 0x08 + +#define HYM8563_ALM_MIN 0x09 +#define HYM8563_ALM_HOUR 0x0a +#define HYM8563_ALM_DAY 0x0b +#define HYM8563_ALM_WEEK 0x0c + +/* Each alarm check can be disabled by setting this bit in the register */ +#define HYM8563_ALM_BIT_DISABLE BIT(7) + +#define HYM8563_CLKOUT 0x0d +#define HYM8563_CLKOUT_ENABLE BIT(7) +#define HYM8563_CLKOUT_32768 0 +#define HYM8563_CLKOUT_1024 1 +#define HYM8563_CLKOUT_32 2 +#define HYM8563_CLKOUT_1 3 +#define HYM8563_CLKOUT_MASK 3 + +#define HYM8563_TMR_CTL 0x0e +#define HYM8563_TMR_CTL_ENABLE BIT(7) +#define HYM8563_TMR_CTL_4096 0 +#define HYM8563_TMR_CTL_64 1 +#define HYM8563_TMR_CTL_1 2 +#define HYM8563_TMR_CTL_1_60 3 +#define HYM8563_TMR_CTL_MASK 3 + +#define HYM8563_TMR_CNT 0x0f + +struct hym8563 { + struct i2c_client *client; + struct rtc_device *rtc; + bool valid; +#ifdef CONFIG_COMMON_CLK + struct clk_hw clkout_hw; +#endif +}; + +/* + * RTC handling + */ + +static int hym8563_rtc_read_time(struct device *dev, struct rtc_time *tm) +{ + struct i2c_client *client = to_i2c_client(dev); + struct hym8563 *hym8563 = i2c_get_clientdata(client); + u8 buf[7]; + int ret; + + if (!hym8563->valid) { + dev_warn(&client->dev, "no valid clock/calendar values available\n"); + return -EPERM; + } + + ret = i2c_smbus_read_i2c_block_data(client, HYM8563_SEC, 7, buf); + + tm->tm_sec = bcd2bin(buf[0] & HYM8563_SEC_MASK); + tm->tm_min = bcd2bin(buf[1] & HYM8563_MIN_MASK); + tm->tm_hour = bcd2bin(buf[2] & HYM8563_HOUR_MASK); + tm->tm_mday = bcd2bin(buf[3] & HYM8563_DAY_MASK); + tm->tm_wday = bcd2bin(buf[4] & HYM8563_WEEKDAY_MASK); /* 0 = Sun */ + tm->tm_mon = bcd2bin(buf[5] & HYM8563_MONTH_MASK) - 1; /* 0 = Jan */ + tm->tm_year = bcd2bin(buf[6]) + 100; + + return 0; +} + +static int hym8563_rtc_set_time(struct device *dev, struct rtc_time *tm) +{ + struct i2c_client *client = to_i2c_client(dev); + struct hym8563 *hym8563 = i2c_get_clientdata(client); + u8 buf[7]; + int ret; + + /* Years >= 2100 are to far in the future, 19XX is to early */ + if (tm->tm_year < 100 || tm->tm_year >= 200) + return -EINVAL; + + buf[0] = bin2bcd(tm->tm_sec); + buf[1] = bin2bcd(tm->tm_min); + buf[2] = bin2bcd(tm->tm_hour); + buf[3] = bin2bcd(tm->tm_mday); + buf[4] = bin2bcd(tm->tm_wday); + buf[5] = bin2bcd(tm->tm_mon + 1); + + /* + * While the HYM8563 has a century flag in the month register, + * it does not seem to carry it over a subsequent write/read. + * So we'll limit ourself to 100 years, starting at 2000 for now. + */ + buf[6] = tm->tm_year - 100; + + /* + * CTL1 only contains TEST-mode bits apart from stop, + * so no need to read the value first + */ + ret = i2c_smbus_write_byte_data(client, HYM8563_CTL1, + HYM8563_CTL1_STOP); + if (ret < 0) + return ret; + + ret = i2c_smbus_write_i2c_block_data(client, HYM8563_SEC, 7, buf); + if (ret < 0) + return ret; + + ret = i2c_smbus_write_byte_data(client, HYM8563_CTL1, 0); + if (ret < 0) + return ret; + + hym8563->valid = true; + + return 0; +} + +static int hym8563_rtc_alarm_irq_enable(struct device *dev, + unsigned int enabled) +{ + struct i2c_client *client = to_i2c_client(dev); + int data; + + data = i2c_smbus_read_byte_data(client, HYM8563_CTL2); + if (data < 0) + return data; + + if (enabled) + data |= HYM8563_CTL2_AIE; + else + data &= ~HYM8563_CTL2_AIE; + + return i2c_smbus_write_byte_data(client, HYM8563_CTL2, data); +}; + +static int hym8563_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm) +{ + struct i2c_client *client = to_i2c_client(dev); + struct rtc_time *alm_tm = &alm->time; + u8 buf[4]; + int ret; + + ret = i2c_smbus_read_i2c_block_data(client, HYM8563_ALM_MIN, 4, buf); + if (ret < 0) + return ret; + + /* The alarm only has a minute accuracy */ + alm_tm->tm_sec = -1; + + alm_tm->tm_min = (buf[0] & HYM8563_ALM_BIT_DISABLE) ? + -1 : + bcd2bin(buf[0] & HYM8563_MIN_MASK); + alm_tm->tm_hour = (buf[1] & HYM8563_ALM_BIT_DISABLE) ? + -1 : + bcd2bin(buf[1] & HYM8563_HOUR_MASK); + alm_tm->tm_mday = (buf[2] & HYM8563_ALM_BIT_DISABLE) ? + -1 : + bcd2bin(buf[2] & HYM8563_DAY_MASK); + alm_tm->tm_wday = (buf[3] & HYM8563_ALM_BIT_DISABLE) ? + -1 : + bcd2bin(buf[3] & HYM8563_WEEKDAY_MASK); + + alm_tm->tm_mon = -1; + alm_tm->tm_year = -1; + + ret = i2c_smbus_read_byte_data(client, HYM8563_CTL2); + if (ret < 0) + return ret; + + if (ret & HYM8563_CTL2_AIE) + alm->enabled = 1; + + return 0; +} + +static int hym8563_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm) +{ + struct i2c_client *client = to_i2c_client(dev); + struct rtc_time *alm_tm = &alm->time; + u8 buf[4]; + int ret; + + /* + * The alarm has no seconds so deal with it + */ + if (alm_tm->tm_sec) { + alm_tm->tm_sec = 0; + alm_tm->tm_min++; + if (alm_tm->tm_min >= 60) { + alm_tm->tm_min = 0; + alm_tm->tm_hour++; + if (alm_tm->tm_hour >= 24) { + alm_tm->tm_hour = 0; + alm_tm->tm_mday++; + if (alm_tm->tm_mday > 31) + alm_tm->tm_mday = 0; + } + } + } + + ret = i2c_smbus_read_byte_data(client, HYM8563_CTL2); + if (ret < 0) + return ret; + + ret &= ~HYM8563_CTL2_AIE; + + ret = i2c_smbus_write_byte_data(client, HYM8563_CTL2, ret); + if (ret < 0) + return ret; + + buf[0] = (alm_tm->tm_min < 60 && alm_tm->tm_min >= 0) ? + bin2bcd(alm_tm->tm_min) : HYM8563_ALM_BIT_DISABLE; + + buf[1] = (alm_tm->tm_hour < 24 && alm_tm->tm_hour >= 0) ? + bin2bcd(alm_tm->tm_hour) : HYM8563_ALM_BIT_DISABLE; + + buf[2] = (alm_tm->tm_mday <= 31 && alm_tm->tm_mday >= 1) ? + bin2bcd(alm_tm->tm_mday) : HYM8563_ALM_BIT_DISABLE; + + buf[3] = (alm_tm->tm_wday < 7 && alm_tm->tm_wday >= 0) ? + bin2bcd(alm_tm->tm_wday) : HYM8563_ALM_BIT_DISABLE; + + ret = i2c_smbus_write_i2c_block_data(client, HYM8563_ALM_MIN, 4, buf); + if (ret < 0) + return ret; + + return hym8563_rtc_alarm_irq_enable(dev, alm->enabled); +} + +static const struct rtc_class_ops hym8563_rtc_ops = { + .read_time = hym8563_rtc_read_time, + .set_time = hym8563_rtc_set_time, + .alarm_irq_enable = hym8563_rtc_alarm_irq_enable, + .read_alarm = hym8563_rtc_read_alarm, + .set_alarm = hym8563_rtc_set_alarm, +}; + +/* + * Handling of the clkout + */ + +#ifdef CONFIG_COMMON_CLK +#define clkout_hw_to_hym8563(_hw) container_of(_hw, struct hym8563, clkout_hw) + +static int clkout_rates[] = { + 32768, + 1024, + 32, + 1, +}; + +static unsigned long hym8563_clkout_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct hym8563 *hym8563 = clkout_hw_to_hym8563(hw); + struct i2c_client *client = hym8563->client; + int ret = i2c_smbus_read_byte_data(client, HYM8563_CLKOUT); + + if (ret < 0) + return 0; + + ret &= HYM8563_CLKOUT_MASK; + return clkout_rates[ret]; +} + +static long hym8563_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 hym8563_clkout_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct hym8563 *hym8563 = clkout_hw_to_hym8563(hw); + struct i2c_client *client = hym8563->client; + int ret = i2c_smbus_read_byte_data(client, HYM8563_CLKOUT); + int i; + + if (ret < 0) + return ret; + + for (i = 0; i < ARRAY_SIZE(clkout_rates); i++) + if (clkout_rates[i] == rate) { + ret &= ~HYM8563_CLKOUT_MASK; + ret |= i; + return i2c_smbus_write_byte_data(client, + HYM8563_CLKOUT, ret); + } + + return -EINVAL; +} + +static int hym8563_clkout_control(struct clk_hw *hw, bool enable) +{ + struct hym8563 *hym8563 = clkout_hw_to_hym8563(hw); + struct i2c_client *client = hym8563->client; + int ret = i2c_smbus_read_byte_data(client, HYM8563_CLKOUT); + + if (ret < 0) + return ret; + + if (enable) + ret |= HYM8563_CLKOUT_ENABLE; + else + ret &= ~HYM8563_CLKOUT_ENABLE; + + return i2c_smbus_write_byte_data(client, HYM8563_CLKOUT, ret); +} + +static int hym8563_clkout_prepare(struct clk_hw *hw) +{ + return hym8563_clkout_control(hw, 1); +} + +static void hym8563_clkout_unprepare(struct clk_hw *hw) +{ + hym8563_clkout_control(hw, 0); +} + +static int hym8563_clkout_is_prepared(struct clk_hw *hw) +{ + struct hym8563 *hym8563 = clkout_hw_to_hym8563(hw); + struct i2c_client *client = hym8563->client; + int ret = i2c_smbus_read_byte_data(client, HYM8563_CLKOUT); + + if (ret < 0) + return ret; + + return !!(ret & HYM8563_CLKOUT_ENABLE); +} + +static const struct clk_ops hym8563_clkout_ops = { + .prepare = hym8563_clkout_prepare, + .unprepare = hym8563_clkout_unprepare, + .is_prepared = hym8563_clkout_is_prepared, + .recalc_rate = hym8563_clkout_recalc_rate, + .round_rate = hym8563_clkout_round_rate, + .set_rate = hym8563_clkout_set_rate, +}; + +static struct clk *hym8563_clkout_register_clk(struct hym8563 *hym8563) +{ + struct i2c_client *client = hym8563->client; + struct device_node *node = client->dev.of_node; + struct clk *clk; + struct clk_init_data init; + int ret; + + ret = i2c_smbus_write_byte_data(client, HYM8563_CLKOUT, + 0); + if (ret < 0) + return ERR_PTR(ret); + + init.name = "hym8563-clkout"; + init.ops = &hym8563_clkout_ops; + init.flags = CLK_IS_ROOT; + init.parent_names = NULL; + init.num_parents = 0; + hym8563->clkout_hw.init = &init; + + /* optional override of the clockname */ + of_property_read_string(node, "clock-output-names", &init.name); + + /* register the clock */ + clk = clk_register(&client->dev, &hym8563->clkout_hw); + + if (!IS_ERR(clk)) + of_clk_add_provider(node, of_clk_src_simple_get, clk); + + return clk; +} +#endif + +/* + * The alarm interrupt is implemented as a level-low interrupt in the + * hym8563, while the timer interrupt uses a falling edge. + * We don't use the timer at all, so the interrupt is requested to + * use the level-low trigger. + */ +static irqreturn_t hym8563_irq(int irq, void *dev_id) +{ + struct hym8563 *hym8563 = (struct hym8563 *)dev_id; + struct i2c_client *client = hym8563->client; + struct mutex *lock = &hym8563->rtc->ops_lock; + int data, ret; + + mutex_lock(lock); + + /* Clear the alarm flag */ + + data = i2c_smbus_read_byte_data(client, HYM8563_CTL2); + if (data < 0) { + dev_err(&client->dev, "%s: error reading i2c data %d\n", + __func__, data); + goto out; + } + + data &= ~HYM8563_CTL2_AF; + + ret = i2c_smbus_write_byte_data(client, HYM8563_CTL2, data); + if (ret < 0) { + dev_err(&client->dev, "%s: error writing i2c data %d\n", + __func__, ret); + } + +out: + mutex_unlock(lock); + return IRQ_HANDLED; +} + +static int hym8563_init_device(struct i2c_client *client) +{ + int ret; + + /* Clear stop flag if present */ + ret = i2c_smbus_write_byte_data(client, HYM8563_CTL1, 0); + if (ret < 0) + return ret; + + ret = i2c_smbus_read_byte_data(client, HYM8563_CTL2); + if (ret < 0) + return ret; + + /* Disable alarm and timer interrupts */ + ret &= ~HYM8563_CTL2_AIE; + ret &= ~HYM8563_CTL2_TIE; + + /* Clear any pending alarm and timer flags */ + if (ret & HYM8563_CTL2_AF) + ret &= ~HYM8563_CTL2_AF; + + if (ret & HYM8563_CTL2_TF) + ret &= ~HYM8563_CTL2_TF; + + ret &= ~HYM8563_CTL2_TI_TP; + + return i2c_smbus_write_byte_data(client, HYM8563_CTL2, ret); +} + +#ifdef CONFIG_PM_SLEEP +static int hym8563_suspend(struct device *dev) +{ + struct i2c_client *client = to_i2c_client(dev); + int ret; + + if (device_may_wakeup(dev)) { + ret = enable_irq_wake(client->irq); + if (ret) { + dev_err(dev, "enable_irq_wake failed, %d\n", ret); + return ret; + } + } + + return 0; +} + +static int hym8563_resume(struct device *dev) +{ + struct i2c_client *client = to_i2c_client(dev); + + if (device_may_wakeup(dev)) + disable_irq_wake(client->irq); + + return 0; +} +#endif + +static SIMPLE_DEV_PM_OPS(hym8563_pm_ops, hym8563_suspend, hym8563_resume); + +static int hym8563_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct hym8563 *hym8563; + int ret; + + hym8563 = devm_kzalloc(&client->dev, sizeof(*hym8563), GFP_KERNEL); + if (!hym8563) + return -ENOMEM; + + hym8563->client = client; + i2c_set_clientdata(client, hym8563); + + device_set_wakeup_capable(&client->dev, true); + + ret = hym8563_init_device(client); + if (ret) { + dev_err(&client->dev, "could not init device, %d\n", ret); + return ret; + } + + ret = devm_request_threaded_irq(&client->dev, client->irq, + NULL, hym8563_irq, + IRQF_TRIGGER_LOW | IRQF_ONESHOT, + client->name, hym8563); + if (ret < 0) { + dev_err(&client->dev, "irq %d request failed, %d\n", + client->irq, ret); + return ret; + } + + /* check state of calendar information */ + ret = i2c_smbus_read_byte_data(client, HYM8563_SEC); + if (ret < 0) + return ret; + + hym8563->valid = !(ret & HYM8563_SEC_VL); + dev_dbg(&client->dev, "rtc information is %s\n", + hym8563->valid ? "valid" : "invalid"); + + hym8563->rtc = devm_rtc_device_register(&client->dev, client->name, + &hym8563_rtc_ops, THIS_MODULE); + if (IS_ERR(hym8563->rtc)) + return PTR_ERR(hym8563->rtc); + + /* the hym8563 alarm only supports a minute accuracy */ + hym8563->rtc->uie_unsupported = 1; + +#ifdef CONFIG_COMMON_CLK + hym8563_clkout_register_clk(hym8563); +#endif + + return 0; +} + +static const struct i2c_device_id hym8563_id[] = { + { "hym8563", 0 }, + {}, +}; +MODULE_DEVICE_TABLE(i2c, hym8563_id); + +static const struct of_device_id hym8563_dt_idtable[] = { + { .compatible = "haoyu,hym8563" }, + {}, +}; +MODULE_DEVICE_TABLE(of, hym8563_dt_idtable); + +static struct i2c_driver hym8563_driver = { + .driver = { + .name = "rtc-hym8563", + .owner = THIS_MODULE, + .pm = &hym8563_pm_ops, + .of_match_table = hym8563_dt_idtable, + }, + .probe = hym8563_probe, + .id_table = hym8563_id, +}; + +module_i2c_driver(hym8563_driver); + +MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>"); +MODULE_DESCRIPTION("HYM8563 RTC driver"); +MODULE_LICENSE("GPL"); |