Merge tag 'dw_apb_timer_of' of git://github.com/mmind/linux-rockchip into next/drivers

From Heiko Stuebner, enhancements for dw_apb_timer:
- use DECLARE_CLOCKSOURCE_OF and convert its users
- handle the sptimer not being present as sched_clock
- add optional handling of timer clocks

* tag 'dw_apb_timer_of' of git://github.com/mmind/linux-rockchip:
  clocksource: dw_apb_timer_of: use clocksource_of_init
  clocksource: dw_apb_timer_of: select DW_APB_TIMER
  clocksource: dw_apb_timer_of: add clock-handling
  clocksource: dw_apb_timer_of: enable the use the clocksource as sched clock

8 files changed, 84 insertions, 39 deletions

diff --git a/Documentation/devicetree/bindings/rtc/dw-apb.txt b/Documentation/devicetree/bindings/rtc/dw-apb.txt
index 93e2b0f048e6..eb2327b2bdb3 100644
--- a/Documentation/devicetree/bindings/rtc/dw-apb.txt
+++ b/Documentation/devicetree/bindings/rtc/dw-apb.txt
@@ -5,9 +5,20 @@ Required properties:
 - reg: physical base address of the controller and length of memory mapped
   region.
 - interrupts: IRQ line for the timer.
+- either clocks+clock-names or clock-frequency properties
+
+Optional properties:
+- clocks        : list of clock specifiers, corresponding to entries in
+                  the clock-names property;
+- clock-names   : should contain "timer" and "pclk" entries, matching entries
+                  in the clocks property.
 - clock-frequency: The frequency in HZ of the timer.
 - clock-freq: For backwards compatibility with picoxcell
 
+If using the clock specifiers, the pclk clock is optional, as not all
+systems may use one.
+
+
 Example:
 
                 timer1: timer@ffc09000 {
@@ -23,3 +34,11 @@ Example:
                                 clock-frequency = <200000000>;
                                 reg = <0xffd00000 0x1000>;
                         };
+
+                timer3: timer@ffe00000 {
+                                compatible = "snps,dw-apb-timer-osc";
+                                interrupts = <0 170 4>;
+                                reg = <0xffe00000 0x1000>;
+                                clocks = <&timer_clk>, <&timer_pclk>;
+                                clock-names = "timer", "pclk";
+                        };
diff --git a/arch/arm/mach-picoxcell/Kconfig b/arch/arm/mach-picoxcell/Kconfig
index 13bae78b215a..b1022f4315f7 100644
--- a/arch/arm/mach-picoxcell/Kconfig
+++ b/arch/arm/mach-picoxcell/Kconfig
@@ -4,7 +4,6 @@ config ARCH_PICOXCELL
         select ARM_PATCH_PHYS_VIRT
         select ARM_VIC
         select CPU_V6K
-        select DW_APB_TIMER
         select DW_APB_TIMER_OF
         select GENERIC_CLOCKEVENTS
         select HAVE_TCM
diff --git a/arch/arm/mach-picoxcell/common.c b/arch/arm/mach-picoxcell/common.c
index 70b441ad1d18..7cde0424d33c 100644
--- a/arch/arm/mach-picoxcell/common.c
+++ b/arch/arm/mach-picoxcell/common.c
@@ -15,7 +15,6 @@
 #include <linux/of_address.h>
 #include <linux/of_irq.h>
 #include <linux/of_platform.h>
-#include <linux/dw_apb_timer.h>
 
 #include <asm/mach/arch.h>
 #include <asm/mach/map.h>
@@ -88,7 +87,6 @@ DT_MACHINE_START(PICOXCELL, "Picochip picoXcell")
         .map_io         = picoxcell_map_io,
         .nr_irqs        = NR_IRQS_LEGACY,
         .init_irq       = irqchip_init,
-        .init_time      = dw_apb_timer_init,
         .init_machine   = picoxcell_init_machine,
         .dt_compat      = picoxcell_dt_match,
         .restart        = picoxcell_wdt_restart,
diff --git a/arch/arm/mach-socfpga/Kconfig b/arch/arm/mach-socfpga/Kconfig
index 566e804d4036..a279fb315069 100644
--- a/arch/arm/mach-socfpga/Kconfig
+++ b/arch/arm/mach-socfpga/Kconfig
@@ -7,7 +7,6 @@ config ARCH_SOCFPGA
         select CLKDEV_LOOKUP
         select COMMON_CLK
         select CPU_V7
-        select DW_APB_TIMER
         select DW_APB_TIMER_OF
         select GENERIC_CLOCKEVENTS
         select GPIO_PL061 if GPIOLIB
diff --git a/arch/arm/mach-socfpga/socfpga.c b/arch/arm/mach-socfpga/socfpga.c
index 46a051359f02..8ea11b472b91 100644
--- a/arch/arm/mach-socfpga/socfpga.c
+++ b/arch/arm/mach-socfpga/socfpga.c
@@ -14,7 +14,6 @@
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
-#include <linux/dw_apb_timer.h>
 #include <linux/clk-provider.h>
 #include <linux/irqchip.h>
 #include <linux/of_address.h>
@@ -120,7 +119,6 @@ DT_MACHINE_START(SOCFPGA, "Altera SOCFPGA")
         .smp            = smp_ops(socfpga_smp_ops),
         .map_io         = socfpga_map_io,
         .init_irq       = socfpga_init_irq,
-        .init_time      = dw_apb_timer_init,
         .init_machine   = socfpga_cyclone5_init,
         .restart        = socfpga_cyclone5_restart,
         .dt_compat      = altera_dt_match,
diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index f151c6cf27c3..5871933c4e51 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -21,6 +21,8 @@ config DW_APB_TIMER
 
 config DW_APB_TIMER_OF
         bool
+        select DW_APB_TIMER
+        select CLKSRC_OF
 
 config ARMADA_370_XP_TIMER
         bool
diff --git a/drivers/clocksource/dw_apb_timer_of.c b/drivers/clocksource/dw_apb_timer_of.c
index ab09ed3742ee..cef554432a33 100644
--- a/drivers/clocksource/dw_apb_timer_of.c
+++ b/drivers/clocksource/dw_apb_timer_of.c
@@ -20,6 +20,7 @@
 #include <linux/of.h>
 #include <linux/of_address.h>
 #include <linux/of_irq.h>
+#include <linux/clk.h>
 
 #include <asm/mach/time.h>
 #include <asm/sched_clock.h>
@@ -27,14 +28,37 @@
 static void timer_get_base_and_rate(struct device_node *np,
                                     void __iomem **base, u32 *rate)
 {
+        struct clk *timer_clk;
+        struct clk *pclk;
+
         *base = of_iomap(np, 0);
 
         if (!*base)
                 panic("Unable to map regs for %s", np->name);
 
+        /*
+         * Not all implementations use a periphal clock, so don't panic
+         * if it's not present
+         */
+        pclk = of_clk_get_by_name(np, "pclk");
+        if (!IS_ERR(pclk))
+                if (clk_prepare_enable(pclk))
+                        pr_warn("pclk for %s is present, but could not be activated\n",
+                                np->name);
+
+        timer_clk = of_clk_get_by_name(np, "timer");
+        if (IS_ERR(timer_clk))
+                goto try_clock_freq;
+
+        if (!clk_prepare_enable(timer_clk)) {
+                *rate = clk_get_rate(timer_clk);
+                return;
+        }
+
+try_clock_freq:
         if (of_property_read_u32(np, "clock-freq", rate) &&
                 of_property_read_u32(np, "clock-frequency", rate))
-                panic("No clock-frequency property for %s", np->name);
+                panic("No clock nor clock-frequency property for %s", np->name);
 }
 
 static void add_clockevent(struct device_node *event_timer)
@@ -57,6 +81,9 @@ static void add_clockevent(struct device_node *event_timer)
         dw_apb_clockevent_register(ced);
 }
 
+static void __iomem *sched_io_base;
+static u32 sched_rate;
+
 static void add_clocksource(struct device_node *source_timer)
 {
         void __iomem *iobase;
@@ -71,9 +98,15 @@ static void add_clocksource(struct device_node *source_timer)
 
         dw_apb_clocksource_start(cs);
         dw_apb_clocksource_register(cs);
-}
 
-static void __iomem *sched_io_base;
+        /*
+         * Fallback to use the clocksource as sched_clock if no separate
+         * timer is found. sched_io_base then points to the current_value
+         * register of the clocksource timer.
+         */
+        sched_io_base = iobase + 0x04;
+        sched_rate = rate;
+}
 
 static u32 read_sched_clock(void)
 {
@@ -89,39 +122,37 @@ static const struct of_device_id sptimer_ids[] __initconst = {
 static void init_sched_clock(void)
 {
         struct device_node *sched_timer;
-        u32 rate;
 
         sched_timer = of_find_matching_node(NULL, sptimer_ids);
-        if (!sched_timer)
-                panic("No RTC for sched clock to use");
+        if (sched_timer) {
+                timer_get_base_and_rate(sched_timer, &sched_io_base,
+                                        &sched_rate);
+                of_node_put(sched_timer);
+        }
 
-        timer_get_base_and_rate(sched_timer, &sched_io_base, &rate);
-        of_node_put(sched_timer);
-
-        setup_sched_clock(read_sched_clock, 32, rate);
+        setup_sched_clock(read_sched_clock, 32, sched_rate);
 }
 
-static const struct of_device_id osctimer_ids[] __initconst = {
-        { .compatible = "picochip,pc3x2-timer" },
-        { .compatible = "snps,dw-apb-timer-osc" },
-        {},
-};
-
-void __init dw_apb_timer_init(void)
+static int num_called;
+static void __init dw_apb_timer_init(struct device_node *timer)
 {
-        struct device_node *event_timer, *source_timer;
-
-        event_timer = of_find_matching_node(NULL, osctimer_ids);
-        if (!event_timer)
-                panic("No timer for clockevent");
-        add_clockevent(event_timer);
-
-        source_timer = of_find_matching_node(event_timer, osctimer_ids);
-        if (!source_timer)
-                panic("No timer for clocksource");
-        add_clocksource(source_timer);
-
-        of_node_put(source_timer);
-
-        init_sched_clock();
+        switch (num_called) {
+        case 0:
+                pr_debug("%s: found clockevent timer\n", __func__);
+                add_clockevent(timer);
+                of_node_put(timer);
+                break;
+        case 1:
+                pr_debug("%s: found clocksource timer\n", __func__);
+                add_clocksource(timer);
+                of_node_put(timer);
+                init_sched_clock();
+                break;
+        default:
+                break;
+        }
+
+        num_called++;
 }
+CLOCKSOURCE_OF_DECLARE(pc3x2_timer, "picochip,pc3x2-timer", dw_apb_timer_init);
+CLOCKSOURCE_OF_DECLARE(apb_timer, "snps,dw-apb-timer-osc", dw_apb_timer_init);
diff --git a/include/linux/dw_apb_timer.h b/include/linux/dw_apb_timer.h
index dd755ce2a5eb..07261d52a6df 100644
--- a/include/linux/dw_apb_timer.h
+++ b/include/linux/dw_apb_timer.h
@@ -53,5 +53,4 @@ void dw_apb_clocksource_start(struct dw_apb_clocksource *dw_cs);
 cycle_t dw_apb_clocksource_read(struct dw_apb_clocksource *dw_cs);
 void dw_apb_clocksource_unregister(struct dw_apb_clocksource *dw_cs);
 
-extern void dw_apb_timer_init(void);
 #endif /* __DW_APB_TIMER_H__ */