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path: root/drivers/rtc/i2c_rtc_emul.c
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Diffstat (limited to 'drivers/rtc/i2c_rtc_emul.c')
-rw-r--r--drivers/rtc/i2c_rtc_emul.c236
1 files changed, 236 insertions, 0 deletions
diff --git a/drivers/rtc/i2c_rtc_emul.c b/drivers/rtc/i2c_rtc_emul.c
new file mode 100644
index 0000000000..20827fdff1
--- /dev/null
+++ b/drivers/rtc/i2c_rtc_emul.c
@@ -0,0 +1,236 @@
+/*
+ * Simulate an I2C real time clock
+ *
+ * Copyright (c) 2015 Google, Inc
+ * Written by Simon Glass <sjg@chromium.org>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+/*
+ * This is a test driver. It starts off with the current time of the machine,
+ * but also supports setting the time, using an offset from the current
+ * clock. This driver is only intended for testing, not accurate
+ * time-keeping. It does not change the system time.
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <fdtdec.h>
+#include <i2c.h>
+#include <os.h>
+#include <rtc.h>
+#include <asm/rtc.h>
+#include <asm/test.h>
+
+#ifdef DEBUG
+#define debug_buffer print_buffer
+#else
+#define debug_buffer(x, ...)
+#endif
+
+DECLARE_GLOBAL_DATA_PTR;
+
+/**
+ * struct sandbox_i2c_rtc_plat_data - platform data for the RTC
+ *
+ * @base_time: Base system time when RTC device was bound
+ * @offset: RTC offset from current system time
+ * @use_system_time: true to use system time, false to use @base_time
+ * @reg: Register values
+ */
+struct sandbox_i2c_rtc_plat_data {
+ long base_time;
+ long offset;
+ bool use_system_time;
+ u8 reg[REG_COUNT];
+};
+
+struct sandbox_i2c_rtc {
+ unsigned int offset_secs;
+};
+
+long sandbox_i2c_rtc_set_offset(struct udevice *dev, bool use_system_time,
+ int offset)
+{
+ struct sandbox_i2c_rtc_plat_data *plat = dev_get_platdata(dev);
+ long old_offset;
+
+ old_offset = plat->offset;
+ plat->use_system_time = use_system_time;
+ if (offset != -1)
+ plat->offset = offset;
+
+ return old_offset;
+}
+
+long sandbox_i2c_rtc_get_set_base_time(struct udevice *dev, long base_time)
+{
+ struct sandbox_i2c_rtc_plat_data *plat = dev_get_platdata(dev);
+ long old_base_time;
+
+ old_base_time = plat->base_time;
+ if (base_time != -1)
+ plat->base_time = base_time;
+
+ return old_base_time;
+}
+
+static void reset_time(struct udevice *dev)
+{
+ struct sandbox_i2c_rtc_plat_data *plat = dev_get_platdata(dev);
+ struct rtc_time now;
+
+ os_localtime(&now);
+ plat->base_time = rtc_mktime(&now);
+ plat->offset = 0;
+ plat->use_system_time = true;
+}
+
+static int sandbox_i2c_rtc_get(struct udevice *dev, struct rtc_time *time)
+{
+ struct sandbox_i2c_rtc_plat_data *plat = dev_get_platdata(dev);
+ struct rtc_time tm_now;
+ long now;
+
+ if (plat->use_system_time) {
+ os_localtime(&tm_now);
+ now = rtc_mktime(&tm_now);
+ } else {
+ now = plat->base_time;
+ }
+
+ return rtc_to_tm(now + plat->offset, time);
+}
+
+static int sandbox_i2c_rtc_set(struct udevice *dev, const struct rtc_time *time)
+{
+ struct sandbox_i2c_rtc_plat_data *plat = dev_get_platdata(dev);
+ struct rtc_time tm_now;
+ long now;
+
+ if (plat->use_system_time) {
+ os_localtime(&tm_now);
+ now = rtc_mktime(&tm_now);
+ } else {
+ now = plat->base_time;
+ }
+ plat->offset = rtc_mktime(time) - now;
+
+ return 0;
+}
+
+/* Update the current time in the registers */
+static int sandbox_i2c_rtc_prepare_read(struct udevice *emul)
+{
+ struct sandbox_i2c_rtc_plat_data *plat = dev_get_platdata(emul);
+ struct rtc_time time;
+ int ret;
+
+ ret = sandbox_i2c_rtc_get(emul, &time);
+ if (ret)
+ return ret;
+
+ plat->reg[REG_SEC] = time.tm_sec;
+ plat->reg[REG_MIN] = time.tm_min;
+ plat->reg[REG_HOUR] = time.tm_hour;
+ plat->reg[REG_MDAY] = time.tm_mday;
+ plat->reg[REG_MON] = time.tm_mon;
+ plat->reg[REG_YEAR] = time.tm_year - 1900;
+ plat->reg[REG_WDAY] = time.tm_wday;
+
+ return 0;
+}
+
+static int sandbox_i2c_rtc_complete_write(struct udevice *emul)
+{
+ struct sandbox_i2c_rtc_plat_data *plat = dev_get_platdata(emul);
+ struct rtc_time time;
+ int ret;
+
+ time.tm_sec = plat->reg[REG_SEC];
+ time.tm_min = plat->reg[REG_MIN];
+ time.tm_hour = plat->reg[REG_HOUR];
+ time.tm_mday = plat->reg[REG_MDAY];
+ time.tm_mon = plat->reg[REG_MON];
+ time.tm_year = plat->reg[REG_YEAR] + 1900;
+ time.tm_wday = plat->reg[REG_WDAY];
+
+ ret = sandbox_i2c_rtc_set(emul, &time);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+static int sandbox_i2c_rtc_xfer(struct udevice *emul, struct i2c_msg *msg,
+ int nmsgs)
+{
+ struct sandbox_i2c_rtc_plat_data *plat = dev_get_platdata(emul);
+ uint offset = 0;
+ int ret;
+
+ debug("\n%s\n", __func__);
+ ret = sandbox_i2c_rtc_prepare_read(emul);
+ if (ret)
+ return ret;
+ for (; nmsgs > 0; nmsgs--, msg++) {
+ int len;
+ u8 *ptr;
+
+ len = msg->len;
+ debug(" %s: msg->len=%d",
+ msg->flags & I2C_M_RD ? "read" : "write",
+ msg->len);
+ if (msg->flags & I2C_M_RD) {
+ debug(", offset %x, len %x: ", offset, len);
+
+ /* Read the register */
+ memcpy(msg->buf, plat->reg + offset, len);
+ memset(msg->buf + len, '\xff', msg->len - len);
+ debug_buffer(0, msg->buf, 1, msg->len, 0);
+ } else if (len >= 1) {
+ ptr = msg->buf;
+ offset = *ptr++ & (REG_COUNT - 1);
+ len--;
+ debug(", set offset %x: ", offset);
+ debug_buffer(0, msg->buf, 1, msg->len, 0);
+
+ /* Write the register */
+ memcpy(plat->reg + offset, ptr, len);
+ if (offset == REG_RESET)
+ reset_time(emul);
+ }
+ }
+ ret = sandbox_i2c_rtc_complete_write(emul);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+struct dm_i2c_ops sandbox_i2c_rtc_emul_ops = {
+ .xfer = sandbox_i2c_rtc_xfer,
+};
+
+static int sandbox_i2c_rtc_bind(struct udevice *dev)
+{
+ reset_time(dev);
+
+ return 0;
+}
+
+static const struct udevice_id sandbox_i2c_rtc_ids[] = {
+ { .compatible = "sandbox,i2c-rtc" },
+ { }
+};
+
+U_BOOT_DRIVER(sandbox_i2c_rtc_emul) = {
+ .name = "sandbox_i2c_rtc_emul",
+ .id = UCLASS_I2C_EMUL,
+ .of_match = sandbox_i2c_rtc_ids,
+ .bind = sandbox_i2c_rtc_bind,
+ .priv_auto_alloc_size = sizeof(struct sandbox_i2c_rtc),
+ .platdata_auto_alloc_size = sizeof(struct sandbox_i2c_rtc_plat_data),
+ .ops = &sandbox_i2c_rtc_emul_ops,
+};
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