Messages in this thread Patch in this message | | | Subject | [PATCH v4] clocksource/drivers/tango_xtal: Add new timer for Tango SoCs | From | Marc Gonzalez <> | Date | Fri, 9 Oct 2015 16:37:45 +0200 |
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Sigma Designs Tango platforms provide a 27 MHz crystal oscillator. Use it for clocksource, sched_clock, and delay_timer.
Signed-off-by: Marc Gonzalez <marc_gonzalez@sigmadesigns.com> --- drivers/clocksource/Kconfig | 4 +++ drivers/clocksource/Makefile | 1 + drivers/clocksource/tango_xtal.c | 71 ++++++++++++++++++++++++++++++++++++++++ 3 files changed, 76 insertions(+) create mode 100644 drivers/clocksource/tango_xtal.c
diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig index 4e57730e0be4..63c878d4d9e3 100644 --- a/drivers/clocksource/Kconfig +++ b/drivers/clocksource/Kconfig @@ -275,6 +275,10 @@ config CLKSRC_MIPS_GIC depends on MIPS_GIC select CLKSRC_OF +config CLKSRC_TANGO_XTAL + bool + select CLKSRC_OF + config CLKSRC_PXA def_bool y if ARCH_PXA || ARCH_SA1100 select CLKSRC_OF if USE_OF diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile index f228354961ca..160970a3963b 100644 --- a/drivers/clocksource/Makefile +++ b/drivers/clocksource/Makefile @@ -55,6 +55,7 @@ obj-$(CONFIG_ARCH_KEYSTONE) += timer-keystone.o obj-$(CONFIG_ARCH_INTEGRATOR_AP) += timer-integrator-ap.o obj-$(CONFIG_CLKSRC_VERSATILE) += versatile.o obj-$(CONFIG_CLKSRC_MIPS_GIC) += mips-gic-timer.o +obj-$(CONFIG_CLKSRC_TANGO_XTAL) += tango_xtal.o obj-$(CONFIG_CLKSRC_IMX_GPT) += timer-imx-gpt.o obj-$(CONFIG_ASM9260_TIMER) += asm9260_timer.o obj-$(CONFIG_H8300) += h8300_timer8.o diff --git a/drivers/clocksource/tango_xtal.c b/drivers/clocksource/tango_xtal.c new file mode 100644 index 000000000000..da67bc2aec63 --- /dev/null +++ b/drivers/clocksource/tango_xtal.c @@ -0,0 +1,71 @@ +#include <linux/clocksource.h> +#include <linux/sched_clock.h> +#include <linux/of_address.h> +#include <linux/printk.h> +#include <linux/delay.h> +#include <linux/init.h> +#include <linux/clk.h> + +#define QUIT_IF(cond, fmt, ...) do if (cond) { \ + static const char format[] __initconst = fmt; \ + pr_err(format, ## __VA_ARGS__); \ + return; \ +} while (0) + +static void __iomem *xtal_in_cnt; +static struct delay_timer delay_timer; + +static unsigned long notrace read_xtal_counter(void) +{ + return readl_relaxed(xtal_in_cnt); +} + +static u64 notrace read_sched_clock(void) +{ + return read_xtal_counter(); +} + +static cycle_t read_clocksource(struct clocksource *cs) +{ + return read_xtal_counter(); +} + +static struct clocksource tango_xtal = { + .name = "tango-xtal", + .rating = 350, + .read = read_clocksource, + .mask = CLOCKSOURCE_MASK(32), + .flags = CLOCK_SOURCE_IS_CONTINUOUS, +}; + +static void __init tango_clocksource_init(struct device_node *np) +{ + struct clk *clk; + int xtal_freq, ret; + + xtal_in_cnt = of_iomap(np, 0); + if (xtal_in_cnt == NULL) { + pr_err("%s: invalid address\n", np->full_name); + return; + } + + clk = of_clk_get(np, 0); + if (IS_ERR(clk)) { + pr_err("%s: invalid clock\n", np->full_name); + return; + } + + xtal_freq = clk_get_rate(clk); + delay_timer.freq = xtal_freq; + delay_timer.read_current_timer = read_xtal_counter; + + ret = clocksource_register_hz(&tango_xtal, xtal_freq); + if (ret != 0) { + pr_err("%s: registration failed\n", np->full_name); + return; + } + sched_clock_register(read_sched_clock, 32, xtal_freq); + register_current_timer_delay(&delay_timer); +} + +CLOCKSOURCE_OF_DECLARE(tango, "sigma,tick-counter", tango_clocksource_init); -- 2.4.5
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