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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#define DRVNAME "rtc-opal"
#include <linux/module.h>#include <linux/err.h>#include <linux/rtc.h>#include <linux/delay.h>#include <linux/bcd.h>#include <linux/platform_device.h>#include <linux/of.h>#include <asm/opal.h>#include <asm/firmware.h>
static void opal_to_tm(u32 y_m_d, u64 h_m_s_ms, struct rtc_time *tm){ tm->tm_year = ((bcd2bin(y_m_d >> 24) * 100) + bcd2bin((y_m_d >> 16) & 0xff)) - 1900; tm->tm_mon = bcd2bin((y_m_d >> 8) & 0xff) - 1; tm->tm_mday = bcd2bin(y_m_d & 0xff); tm->tm_hour = bcd2bin((h_m_s_ms >> 56) & 0xff); tm->tm_min = bcd2bin((h_m_s_ms >> 48) & 0xff); tm->tm_sec = bcd2bin((h_m_s_ms >> 40) & 0xff);
tm->tm_wday = -1;}
static void tm_to_opal(struct rtc_time *tm, u32 *y_m_d, u64 *h_m_s_ms){ *y_m_d |= ((u32)bin2bcd((tm->tm_year + 1900) / 100)) << 24; *y_m_d |= ((u32)bin2bcd((tm->tm_year + 1900) % 100)) << 16; *y_m_d |= ((u32)bin2bcd((tm->tm_mon + 1))) << 8; *y_m_d |= ((u32)bin2bcd(tm->tm_mday));
*h_m_s_ms |= ((u64)bin2bcd(tm->tm_hour)) << 56; *h_m_s_ms |= ((u64)bin2bcd(tm->tm_min)) << 48; *h_m_s_ms |= ((u64)bin2bcd(tm->tm_sec)) << 40;}
static int opal_get_rtc_time(struct device *dev, struct rtc_time *tm){ s64 rc = OPAL_BUSY; int retries = 10; u32 y_m_d; u64 h_m_s_ms; __be32 __y_m_d; __be64 __h_m_s_ms;
while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) { rc = opal_rtc_read(&__y_m_d, &__h_m_s_ms); if (rc == OPAL_BUSY_EVENT) { msleep(OPAL_BUSY_DELAY_MS); opal_poll_events(NULL); } else if (rc == OPAL_BUSY) { msleep(OPAL_BUSY_DELAY_MS); } else if (rc == OPAL_HARDWARE || rc == OPAL_INTERNAL_ERROR) { if (retries--) { msleep(10); /* Wait 10ms before retry */ rc = OPAL_BUSY; /* go around again */ } } }
if (rc != OPAL_SUCCESS) return -EIO;
y_m_d = be32_to_cpu(__y_m_d); h_m_s_ms = be64_to_cpu(__h_m_s_ms); opal_to_tm(y_m_d, h_m_s_ms, tm);
return 0;}
static int opal_set_rtc_time(struct device *dev, struct rtc_time *tm){ s64 rc = OPAL_BUSY; int retries = 10; u32 y_m_d = 0; u64 h_m_s_ms = 0;
tm_to_opal(tm, &y_m_d, &h_m_s_ms);
while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) { rc = opal_rtc_write(y_m_d, h_m_s_ms); if (rc == OPAL_BUSY_EVENT) { msleep(OPAL_BUSY_DELAY_MS); opal_poll_events(NULL); } else if (rc == OPAL_BUSY) { msleep(OPAL_BUSY_DELAY_MS); } else if (rc == OPAL_HARDWARE || rc == OPAL_INTERNAL_ERROR) { if (retries--) { msleep(10); /* Wait 10ms before retry */ rc = OPAL_BUSY; /* go around again */ } } }
return rc == OPAL_SUCCESS ? 0 : -EIO;}
/* * TPO Timed Power-On * * TPO get/set OPAL calls care about the hour and min and to make it consistent * with the rtc utility time conversion functions, we use the 'u64' to store * its value and perform bit shift by 32 before use.. */static int opal_get_tpo_time(struct device *dev, struct rtc_wkalrm *alarm){ __be32 __y_m_d, __h_m; struct opal_msg msg; int rc, token; u64 h_m_s_ms; u32 y_m_d;
token = opal_async_get_token_interruptible(); if (token < 0) { if (token != -ERESTARTSYS) pr_err("Failed to get the async token\n");
return token; }
rc = opal_tpo_read(token, &__y_m_d, &__h_m); if (rc != OPAL_ASYNC_COMPLETION) { rc = -EIO; goto exit; }
rc = opal_async_wait_response(token, &msg); if (rc) { rc = -EIO; goto exit; }
rc = opal_get_async_rc(msg); if (rc != OPAL_SUCCESS) { rc = -EIO; goto exit; }
y_m_d = be32_to_cpu(__y_m_d); h_m_s_ms = ((u64)be32_to_cpu(__h_m) << 32);
/* check if no alarm is set */ if (y_m_d == 0 && h_m_s_ms == 0) { pr_debug("No alarm is set\n"); rc = -ENOENT; goto exit; } else { pr_debug("Alarm set to %x %llx\n", y_m_d, h_m_s_ms); }
opal_to_tm(y_m_d, h_m_s_ms, &alarm->time);
exit: opal_async_release_token(token); return rc;}
/* Set Timed Power-On */static int opal_set_tpo_time(struct device *dev, struct rtc_wkalrm *alarm){ u64 h_m_s_ms = 0; struct opal_msg msg; u32 y_m_d = 0; int token, rc;
/* if alarm is enabled */ if (alarm->enabled) { tm_to_opal(&alarm->time, &y_m_d, &h_m_s_ms); pr_debug("Alarm set to %x %llx\n", y_m_d, h_m_s_ms);
} else { pr_debug("Alarm getting disabled\n"); }
token = opal_async_get_token_interruptible(); if (token < 0) { if (token != -ERESTARTSYS) pr_err("Failed to get the async token\n");
return token; }
/* TPO, we care about hour and minute */ rc = opal_tpo_write(token, y_m_d, (u32)((h_m_s_ms >> 32) & 0xffff0000)); if (rc != OPAL_ASYNC_COMPLETION) { rc = -EIO; goto exit; }
rc = opal_async_wait_response(token, &msg); if (rc) { rc = -EIO; goto exit; }
rc = opal_get_async_rc(msg); if (rc != OPAL_SUCCESS) rc = -EIO;
exit: opal_async_release_token(token); return rc;}
static int opal_tpo_alarm_irq_enable(struct device *dev, unsigned int enabled){ struct rtc_wkalrm alarm = { .enabled = 0 };
/* * TPO is automatically enabled when opal_set_tpo_time() is called with * non-zero rtc-time. We only handle disable case which needs to be * explicitly told to opal. */ return enabled ? 0 : opal_set_tpo_time(dev, &alarm);}
static const struct rtc_class_ops opal_rtc_ops = { .read_time = opal_get_rtc_time, .set_time = opal_set_rtc_time, .read_alarm = opal_get_tpo_time, .set_alarm = opal_set_tpo_time, .alarm_irq_enable = opal_tpo_alarm_irq_enable,};
static int opal_rtc_probe(struct platform_device *pdev){ struct rtc_device *rtc;
rtc = devm_rtc_allocate_device(&pdev->dev); if (IS_ERR(rtc)) return PTR_ERR(rtc);
if (pdev->dev.of_node && (of_property_read_bool(pdev->dev.of_node, "wakeup-source") || of_property_read_bool(pdev->dev.of_node, "has-tpo")/* legacy */)) device_set_wakeup_capable(&pdev->dev, true); else clear_bit(RTC_FEATURE_ALARM, rtc->features);
rtc->ops = &opal_rtc_ops; rtc->range_min = RTC_TIMESTAMP_BEGIN_0000; rtc->range_max = RTC_TIMESTAMP_END_9999; clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc->features);
return devm_rtc_register_device(rtc);}
static const struct of_device_id opal_rtc_match[] = { { .compatible = "ibm,opal-rtc", }, { }};MODULE_DEVICE_TABLE(of, opal_rtc_match);
static const struct platform_device_id opal_rtc_driver_ids[] = { { .name = "opal-rtc", }, { }};MODULE_DEVICE_TABLE(platform, opal_rtc_driver_ids);
static struct platform_driver opal_rtc_driver = { .probe = opal_rtc_probe, .id_table = opal_rtc_driver_ids, .driver = { .name = DRVNAME, .of_match_table = opal_rtc_match, },};
static int __init opal_rtc_init(void){ if (!firmware_has_feature(FW_FEATURE_OPAL)) return -ENODEV;
return platform_driver_register(&opal_rtc_driver);}
static void __exit opal_rtc_exit(void){ platform_driver_unregister(&opal_rtc_driver);}
MODULE_AUTHOR("Neelesh Gupta <neelegup@linux.vnet.ibm.com>");MODULE_DESCRIPTION("IBM OPAL RTC driver");MODULE_LICENSE("GPL");
module_init(opal_rtc_init);module_exit(opal_rtc_exit);