linux-imx

/*

 * Copyright (C) 2012 Altera Corporation

 * Copyright (c) 2011 Picochip Ltd., Jamie Iles

 *

 * Modified from mach-picoxcell/time.c

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as

 * published by the Free Software Foundation.

 *

 * 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, see <http://www.gnu.org/licenses/>.

 */

#include <linux/delay.h>

#include <linux/dw_apb_timer.h>

#include <linux/of.h>

#include <linux/of_address.h>

#include <linux/of_irq.h>

#include <linux/clk.h>

#include <linux/reset.h>

#include <linux/sched_clock.h>

​

static void __init timer_get_base_and_rate(struct device_node *np,

                    void __iomem **base, u32 *rate)

{

    struct clk *timer_clk;

    struct clk *pclk;

    struct reset_control *rstc;

​

    *base = of_iomap(np, 0);

​

    if (!*base)

        panic("Unable to map regs for %pOFn", np);

​

    /*

     * Reset the timer if the reset control is available, wiping

     * out the state the firmware may have left it

     */

    rstc = of_reset_control_get(np, NULL);

    if (!IS_ERR(rstc)) {

        reset_control_assert(rstc);

        reset_control_deassert(rstc);

    }

​

    /*

     * 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 %pOFn is present, but could not be activated\n",

                np);

​

    timer_clk = of_clk_get_by_name(np, "timer");

    if (IS_ERR(timer_clk))

        goto try_clock_freq;

​