From mboxrd@z Thu Jan 1 00:00:00 1970 From: linux@rempel-privat.de (Oleksij Rempel) Date: Sun, 21 Sep 2014 20:45:49 +0200 Subject: [PATCH v2 6/8] clocksource: add asm9260_timer driver In-Reply-To: <1411325151-15107-1-git-send-email-linux@rempel-privat.de> References: <1411324904-14881-1-git-send-email-linux@rempel-privat.de> <1411325151-15107-1-git-send-email-linux@rempel-privat.de> Message-ID: <1411325151-15107-5-git-send-email-linux@rempel-privat.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Signed-off-by: Oleksij Rempel --- drivers/clocksource/Makefile | 1 + drivers/clocksource/asm9260_timer.c | 244 ++++++++++++++++++++++++++++++++++++ 2 files changed, 245 insertions(+) create mode 100644 drivers/clocksource/asm9260_timer.c diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile index 7fd9fd1..19211c5 100644 --- a/drivers/clocksource/Makefile +++ b/drivers/clocksource/Makefile @@ -44,3 +44,4 @@ obj-$(CONFIG_CLKSRC_METAG_GENERIC) += metag_generic.o obj-$(CONFIG_ARCH_HAS_TICK_BROADCAST) += dummy_timer.o obj-$(CONFIG_ARCH_KEYSTONE) += timer-keystone.o obj-$(CONFIG_CLKSRC_VERSATILE) += versatile.o +obj-$(CONFIG_MACH_ASM9260) += asm9260_timer.o diff --git a/drivers/clocksource/asm9260_timer.c b/drivers/clocksource/asm9260_timer.c new file mode 100644 index 0000000..bcc8204 --- /dev/null +++ b/drivers/clocksource/asm9260_timer.c @@ -0,0 +1,244 @@ +/* + * Copyright (C) 2014 Oleksij Rempel + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, + * MA 02110-1301, USA. + * + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + + +/* + * this device provide 4 offsets for each register: + * 0x0 - plain read write mode + * 0x4 - set mode, OR logic. + * 0x8 - clr mode, XOR logic. + * 0xc - togle mode. + */ +#define SET_REG 4 +#define CLR_REG 8 + +#define HW_IR 0x0000 /* RW. Interrupt */ +#define BM_IR_CR0 BIT(4) +#define BM_IR_MR3 BIT(3) +#define BM_IR_MR2 BIT(2) +#define BM_IR_MR1 BIT(1) +#define BM_IR_MR0 BIT(0) + +#define HW_TCR 0x0010 /* RW. Timer controller */ +/* BM_C*_RST + * Timer Counter and the Prescale Counter are synchronously reset on the + * next positive edge of PCLK. The counters remain reset until TCR[1] is + * returned to zero. */ +#define BM_C3_RST BIT(7) +#define BM_C2_RST BIT(6) +#define BM_C1_RST BIT(5) +#define BM_C0_RST BIT(4) +/* BM_C*_EN + * 1 - Timer Counter and Prescale Counter are enabled for counting + * 0 - counters are disabled */ +#define BM_C3_EN BIT(3) +#define BM_C2_EN BIT(2) +#define BM_C1_EN BIT(1) +#define BM_C0_EN BIT(0) + +#define HW_DIR 0x0020 /* RW. Direction? */ +/* 00 - count up + * 01 - count down + * 10 - ?? 2^n/2 */ +#define BM_DIR0_SHIFT 0 +#define BM_DIR1_SHIFT 4 +#define BM_DIR2_SHIFT 8 +#define BM_DIR3_SHIFT 12 + +#define HW_TC0 0x0030 /* RO. Timer counter 0 */ +/* HW_TC*. Timer counter owerflow (0xffff.ffff to 0x0000.0000) do not generate + * interrupt. This registers can be used to detect overflow */ +#define HW_TC1 0x0040 +#define HW_TC2 0x0050 +#define HW_TC3 0x0060 + +#define HW_PR 0x0070 /* RW. prescaler */ +#define HW_PC 0x0080 /* RO. Prescaler counter */ +#define HW_MCR 0x0090 /* RW. Match control */ +/* enable interrupt on match */ +#define BM_MCR_INT_EN(n) (1 << (n * 3 + 0)) +/* enable TC reset on match */ +#define BM_MCR_RES_EN(n) (1 << (n * 3 + 1)) +/* enable stop TC on match */ +#define BM_MCR_STOP_EN(n) (1 << (n * 3 + 2)) + +#define HW_MR0 0x00a0 /* RW. Match reg */ +#define HW_MR1 0x00b0 +#define HW_MR2 0x00C0 +#define HW_MR3 0x00D0 +#define HW_CCR 0x00E0 /* RW. Capture control */ +#define HW_CR0 0x00F0 /* RO. Capture reg */ +#define HW_CR1 0x0100 +#define HW_CR2 0x0110 +#define HW_CR3 0x0120 +#define HW_EMR 0x0130 /* RW. External Match */ +#define HW_PWMTH0 0x0140 /* RW. PWM width */ +#define HW_PWMTH1 0x0150 +#define HW_PWMTH2 0x0160 +#define HW_PWMTH3 0x0170 +#define HW_CTCR 0x0180 /* Counter control */ +#define HW_PWMC 0x0190 /* PWM control */ + +static void __iomem *base; +static unsigned long ticks_per_jiffy; + +static int asm9260_timer_set_next_event(unsigned long delta, + struct clock_event_device *dev) +{ + /* configure match count for TC0 */ + writel_relaxed(delta, base + HW_MR0); + /* enable TC0 */ + writel_relaxed(BM_C0_EN, base + HW_TCR + SET_REG); + return 0; +} + +static void asm9260_timer_set_mode(enum clock_event_mode mode, + struct clock_event_device *evt) +{ + /* stop timer0 */ + writel_relaxed(BM_C0_EN, base + HW_TCR + CLR_REG); + + switch (mode) { + case CLOCK_EVT_MODE_PERIODIC: + /* disable reset and stop on match */ + writel_relaxed(BM_MCR_RES_EN(0) | BM_MCR_STOP_EN(0), + base + HW_MCR + CLR_REG); + /* configure match count for TC0 */ + writel_relaxed(ticks_per_jiffy, base + HW_MR0); + /* enable TC0 */ + writel_relaxed(BM_C0_EN, base + HW_TCR + SET_REG); + break; + case CLOCK_EVT_MODE_ONESHOT: + /* enable reset and stop on match */ + writel_relaxed(BM_MCR_RES_EN(0) | BM_MCR_STOP_EN(0), + base + HW_MCR + SET_REG); + break; + default: + break; + } +} + +static struct clock_event_device asm9260_clockevent_device = { + .name = "asm9260-clockevent-dev", + .rating = 200, + .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT, + .set_next_event = asm9260_timer_set_next_event, + .set_mode = asm9260_timer_set_mode, +}; + +static irqreturn_t asm9260_timer_interrupt(int irq, void *dev_id) +{ + struct clock_event_device *evt = &asm9260_clockevent_device; + + evt->event_handler(evt); + + writel_relaxed(BM_IR_MR0, base + HW_IR); + + return IRQ_HANDLED; +} + +static struct irqaction asm9260_timer_irq = { + .name = "asm9260-clockevent-dev", + .flags = IRQF_TIMER | IRQF_IRQPOLL, + .handler = asm9260_timer_interrupt, +}; + +/* + * --------------------------------------------------------------------------- + * Timer initialization + * --------------------------------------------------------------------------- + */ + +static void __init asm9260_clockevent_init(struct clk *clk) +{ + unsigned long rate = clk_get_rate(clk); + + ticks_per_jiffy = DIV_ROUND_CLOSEST(rate, HZ); + asm9260_clockevent_device.cpumask = cpumask_of(0); + clockevents_config_and_register(&asm9260_clockevent_device, + rate, 0x2c00, 0xfffffffe); +} + +static void __init asm9260_clocksource_init(struct clk *clk) +{ + unsigned long hz = clk_get_rate(clk); + + clocksource_mmio_init(base + HW_TC1, + "asm9260-clocksource", hz, + 200, 32, clocksource_mmio_readl_up); + + /* Seems like we can't use counter without match register even if + * actions for MR are disabled. */ + writel_relaxed(0xffffffff, base + HW_MR1); + /* enable TC1 */ + writel_relaxed(BM_C1_EN, base + HW_TCR + SET_REG); +} + +static void __init asm9260_timer_init(struct device_node *np) +{ + int irq; + struct clk *clk; + struct resource res; + int ret; + + of_address_to_resource(np, 0, &res); + if (!request_mem_region(res.start, resource_size(&res), + "asm9260-timer")) + panic("%s: unable to request mem region", np->name); + + base = ioremap_nocache(res.start, resource_size(&res)); + if (!base) + panic("%s: unable to map resource", np->name); + + clk = of_clk_get(np, 0); + + ret = clk_prepare_enable(clk); + if (ret) + panic("Failed to enable clk!\n"); + + irq = irq_of_parse_and_map(np, 0); + setup_irq(irq, &asm9260_timer_irq); + + /* set all timers for count-up */ + writel_relaxed(0, base + HW_DIR); + /* disable divider */ + writel_relaxed(0, base + HW_PR); + /* make sure all timers use every rising PCLK edge. */ + writel_relaxed(0, base + HW_CTCR); + /* enable interrupt for TC0 and clean setting for all other lines */ + writel_relaxed(BM_MCR_INT_EN(0) , base + HW_MCR); + + asm9260_clocksource_init(clk); + asm9260_clockevent_init(clk); +} +CLOCKSOURCE_OF_DECLARE(asm9260_timer, "alphascale,asm9260-timer", + asm9260_timer_init); -- 1.9.1