@@ -453,6 +453,7 @@ config SPRD_TIMER
bool "Spreadtrum timer driver" if COMPILE_TEST
depends on HAS_IOMEM
select TIMER_OF
+ select PERSISTENT_CLOCK
help
Enables support for the Spreadtrum timer driver.
@@ -3,8 +3,11 @@
* Copyright (C) 2017 Spreadtrum Communications Inc.
*/
+#include <linux/clk.h>
#include <linux/init.h>
#include <linux/interrupt.h>
+#include <linux/of_address.h>
+#include <linux/persistent_clock.h>
#include "timer-of.h"
@@ -157,3 +160,80 @@ static int __init sprd_timer_init(struct device_node *np)
}
TIMER_OF_DECLARE(sc9860_timer, "sprd,sc9860-timer", sprd_timer_init);
+
+void __iomem *pbase;
+
+static u64 sprd_persistent_timer_read(void)
+{
+ return ~(u64)readl_relaxed(pbase + TIMER_VALUE_SHDW_LO) &
+ CLOCKSOURCE_MASK(32);
+}
+
+static void sprd_persistent_timer_disable(void)
+{
+ sprd_timer_disable(pbase);
+}
+
+static void sprd_persistent_timer_enable(void)
+{
+ sprd_timer_disable(pbase);
+ sprd_timer_update_counter(pbase, TIMER_VALUE_LO_MASK);
+ sprd_timer_enable(pbase, TIMER_CTL_PERIOD_MODE);
+}
+
+static int __init sprd_persistent_timer_init(struct device_node *np)
+{
+ struct clk *clk;
+ u32 freq;
+ int ret;
+
+ clk = of_clk_get(np, 0);
+ if (IS_ERR(clk)) {
+ pr_err("Can't get timer clock for %pOF\n", np);
+ return PTR_ERR(clk);
+ }
+
+ ret = clk_prepare_enable(clk);
+ if (ret) {
+ pr_err("Failed to enable clock for %pOF\n", np);
+ clk_put(clk);
+ return ret;
+ }
+
+ freq = clk_get_rate(clk);
+ if (!freq) {
+ pr_err("Failed to get clock rate for %pOF\n", np);
+ ret = -EINVAL;
+ goto clk_rate_err;
+ }
+
+ pbase = of_io_request_and_map(np, 0, of_node_full_name(np));
+ if (IS_ERR(pbase)) {
+ pr_err("Can't map timer registers for %pOF\n", np);
+ ret = PTR_ERR(pbase);
+ goto clk_rate_err;
+ }
+
+ sprd_persistent_timer_enable();
+
+ ret = persistent_clock_init_and_register(sprd_persistent_timer_read,
+ CLOCKSOURCE_MASK(32), freq, 0);
+ if (ret) {
+ pr_err("Failed to register persistent clock for %pOF\n", np);
+ goto persist_err;
+ }
+
+ return 0;
+
+persist_err:
+ sprd_persistent_timer_disable();
+ iounmap(pbase);
+clk_rate_err:
+ clk_disable_unprepare(clk);
+ clk_put(clk);
+
+ return ret;
+}
+
+TIMER_OF_DECLARE(sc9860_persistent_timer, "sprd,sc9860-persistent-timer",
+ sprd_persistent_timer_init);
On Spreadtrum SC9860 platform, we need one persistent timer to calculate the suspend time to compensate the OS time. This patch registers one Spreadtrum AON timer as persistent timer, which runs at 32bit and periodic mode. Signed-off-by: Baolin Wang <baolin.wang@linaro.org> --- drivers/clocksource/Kconfig | 1 + drivers/clocksource/timer-sprd.c | 80 ++++++++++++++++++++++++++++++++++++++ 2 files changed, 81 insertions(+)