Thara Gopinath <thara@xxxxxx> writes:
> This patch converts OMAP2/OMAP3/OMAP4 dual mode timers into
> platform devices using omap hwmod, omap device and runtime pm frameworks.
> This patch also allows GPTIMER1 and GPTIMER2 to be registered as
> early devices. This will allow GPTIMER1 to be registered as
> system timer very early on in the system boot up sequence.
> Later during normal plaform_device_register these are converted
> to normal platform device.
>
> Signed-off-by: Thara Gopinath <thara@xxxxxx>
First, a couple of general comments.
You're using the runtime PM API here in the device layer hooks. This
should be in the driver. It will be a noop for OMAP1 since there will
be no runtime PM implementation, but that is fine. Moving this into
the driver should allow you to get rid of the enable/disable clock
hooks you currently have in platform_data as well (for early timers
you could leave them enabled until they are converted to "normal"
timers.)
Also, I suggested this to Charu as well for GPIO and WDT, but we
should leave out the handling of the #ifndef CONFIG_PM_RUNTIME from
this code. I'd rather not have every driver handling that special
case. Instead I propose we handle this in the omap_hwmod init sequence
by enabling all the hwmods if !CONFIG_PM_RUNTIME.
> ---
> arch/arm/mach-omap2/Makefile | 3 +-
> arch/arm/mach-omap2/dmtimers.c | 296 ++++++++++++++++++++++++++++++++++++++++
> arch/arm/mach-omap2/dmtimers.h | 57 ++++++++
> arch/arm/mach-omap2/timer-gp.c | 2 -
> 4 files changed, 355 insertions(+), 3 deletions(-)
> create mode 100644 arch/arm/mach-omap2/dmtimers.c
> create mode 100644 arch/arm/mach-omap2/dmtimers.h
>
> diff --git a/arch/arm/mach-omap2/Makefile b/arch/arm/mach-omap2/Makefile
> index dd3a24a..9299e4f 100644
> --- a/arch/arm/mach-omap2/Makefile
> +++ b/arch/arm/mach-omap2/Makefile
> @@ -3,7 +3,8 @@
> #
>
> # Common support
> -obj-y := id.o io.o control.o mux.o devices.o serial.o gpmc.o timer-gp.o
> +obj-y := id.o io.o control.o mux.o devices.o serial.o gpmc.o timer-gp.o \
> + dmtimers.o
>
> omap-2-3-common = irq.o sdrc.o
> hwmod-common = omap_hwmod.o \
> diff --git a/arch/arm/mach-omap2/dmtimers.c b/arch/arm/mach-omap2/dmtimers.c
> new file mode 100644
> index 0000000..6a2caf3
> --- /dev/null
> +++ b/arch/arm/mach-omap2/dmtimers.c
> @@ -0,0 +1,296 @@
> +/**
> + * OMAP2 Dual-Mode Timers
> + *
> + * Copyright (C) 2010 Texas Instruments, Inc.
> + * Thara Gopinath <thara@xxxxxx>
> + *
> + * 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.
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/delay.h>
> +#include <linux/io.h>
> +#include <linux/err.h>
> +#include <linux/slab.h>
> +#include <linux/pm_runtime.h>
> +
> +#include <mach/irqs.h>
> +#include <plat/dmtimer.h>
> +#include <plat/omap_hwmod.h>
> +#include <plat/omap_device.h>
> +
> +#include "dmtimers.h"
> +
> +#define NO_EARLY_TIMERS 2
Please use NR_EARLY_TIMERS
> +#define OMAP2_DM_TIMER_COUNT 12
> +#define OMAP3PLUS_DM_TIMER_COUNT 11
and these you should get rid of as Benoit pointed out. More on this
below.
> +static char *omap2_dm_source_names[] __initdata = {
> + "sys_ck",
> + "func_32k_ck",
> + "alt_ck",
> + NULL
> +};
> +static struct clk *omap2_dm_source_clocks[3];
> +
> +static char *omap3_dm_source_names[] __initdata = {
> + "sys_ck",
> + "omap_32k_fck",
> + NULL
> +};
> +static struct clk *omap3_dm_source_clocks[2];
> +
> +static char *omap4_dm_source_names[] __initdata = {
> + "sys_ck",
> + "sys_32k_ck",
> + NULL
> +};
> +static struct clk *omap4_dm_source_clocks[2];
> +
> +static struct clk **omap_dm_source_clocks;
> +
> +static void omap2_dm_timer_enable(struct platform_device *pdev)
> +{
> +
> + if (pm_runtime_get_sync(&pdev->dev))
> + dev_warn(&pdev->dev, "%s: Unable to enable the timer\n",
> + __func__);
> +#ifndef CONFIG_PM_RUNTIME
> + if (omap_device_enable(pdev))
> + dev_warn(&pdev->dev, "%s: Unable to enable the timer\n",
> + __func__);
> +#endif
> +}
> +
> +static void omap2_dm_timer_disable(struct platform_device *pdev)
> +{
> +
> + if (pm_runtime_put_sync(&pdev->dev))
> + dev_warn(&pdev->dev, "%s: Unable to disable the timer\n",
> + __func__);
> +#ifndef CONFIG_PM_RUNTIME
> + if (omap_device_idle(pdev))
> + dev_warn(&pdev->dev, "%s: Unable to disable the timer\n",
> + __func__);
> +#endif
> +}
> +
> +static int omap2_dm_timer_set_src(struct platform_device *pdev,
> + struct clk *timer_clk, int source)
> +{
> + int ret;
> +
> + if (IS_ERR(timer_clk)) {
> + dev_warn(&pdev->dev, "%s: Not able get the clock pointer\n",
> + __func__);
> + return -EINVAL;
> + }
> +
> + clk_disable(timer_clk);
> + ret = clk_set_parent(timer_clk, omap_dm_source_clocks[source]);
> + if (ret)
> + dev_warn(&pdev->dev, "%s: Not able to change the"
> + "fclk source\n", __func__);
> +
> + clk_enable(timer_clk);
> + /*
> + * When the functional clock disappears, too quick writes seem
> + * to cause an abort. XXX Is this still necessary?
> + */
> + __delay(150000);
> + return ret;
> +}
> +
> +static int omap2_dm_timer_set_clk(struct platform_device *pdev, int source)
> +{
> + struct clk *timer_clk = clk_get(&pdev->dev, "fck");
> +
> + return omap2_dm_timer_set_src(pdev, timer_clk, source);
Missing a clk_put() here.
> +}
> +
> +static struct clk *omap2_dm_timer_get_fclk(struct platform_device *pdev)
> +{
> + return clk_get(&pdev->dev, "fck");
> +}
> +
> +/* API's to be used by early timer devices */
> +static void __init omap2_dm_early_timer_enable(struct platform_device *pdev)
> +{
> + if (omap_device_enable(pdev))
> + dev_warn(&pdev->dev, "%s: Unable to enable the timer\n",
> + __func__);
> +}
> +
> +static void __init omap2_dm_early_timer_disable(struct platform_device *pdev)
> +{
> + if (omap_device_idle(pdev))
> + dev_warn(&pdev->dev, "%s: Unable to disable the timer\n",
> + __func__);
> +}
I suggest just dropping the early enable/disable hooks and leaving
them enabled. Once the "normal" probe runs, they can be disabled if
unused. That will avoid having to havea special set of hooks for
early devices.
> +static int __init omap2_dm_early_timer_set_clk(struct platform_device *pdev,
> + int source)
> +{
> + struct omap_device *odev = to_omap_device(pdev);
> +
> + return omap2_dm_timer_set_src(pdev, odev->hwmods[0]->_clk, source);
> +}
As Benoit mentioned, I think we may need an omap_hwmod_get_clk() or something
to avoid touching hwmod internals and make this cleaner.
That being said, why do you need a special "early" version of the
set_clk. You could use this version for both.
> +static struct clk __init *omap2_dm_early_timer_get_fclk
> + (struct platform_device *pdev)
> +{
> + struct omap_device *odev = to_omap_device(pdev);
> +
> + return odev->hwmods[0]->_clk;
> +}
Likewise, this could use a new function omap_hwmod_get_clk() and could
be used for both early and normal versions.
> +/* One time initializations */
> +static void __init omap2_dm_timer_setup(void)
> +{
> + static int is_initialized;
> + char **src_clk_name;
> + int i;
> +
> + /*
> + * Check if setup has already been done as part of early init.
> + * If yes avoid doing it again.
> + */
> + if (is_initialized)
> + return;
> +
> + if (cpu_is_omap24xx()) {
> + src_clk_name = omap2_dm_source_names;
> + omap_dm_source_clocks = omap2_dm_source_clocks;
> + } else if (cpu_is_omap34xx()) {
> + src_clk_name = omap3_dm_source_names;
> + omap_dm_source_clocks = omap3_dm_source_clocks;
> + } else if (cpu_is_omap44xx()) {
> + src_clk_name = omap4_dm_source_names;
> + omap_dm_source_clocks = omap4_dm_source_clocks;
> + } else {
> + pr_err("%s: Chip support not yet added\n", __func__);
> + return;
> + }
> +
> + /* Initialize the dmtimer src clocks */
> + for (i = 0; src_clk_name[i] != NULL; i++)
> + omap_dm_source_clocks[i] =
> + clk_get(NULL, src_clk_name[i]);
> +
> + /* Number of dmtimers in the system */
> + if (cpu_is_omap24xx())
> + omap_dm_timer_count = OMAP2_DM_TIMER_COUNT;
> + else
> + omap_dm_timer_count = OMAP3PLUS_DM_TIMER_COUNT;
This shouldn't be necessary. You should have a count after iterating
through the hwmods in this class.
> + is_initialized = 1;
> +}
> +
> +struct omap_device_pm_latency omap2_dmtimer_latency[] = {
> + {
> + .deactivate_func = omap_device_idle_hwmods,
> + .activate_func = omap_device_enable_hwmods,
> + .flags = OMAP_DEVICE_LATENCY_AUTO_ADJUST,
indentation
> + },
> +};
> +
> +int __init omap2_get_early_timer_count(void)
> +{
> + return NO_EARLY_TIMERS;
> +}
> +
> +void __init omap2_dm_timer_early_init(void)
> +{
> + int i = 0;
> + char *name = "dmtimer";
insert blank line
> + do {
minor nit, but this would be clearer if it were a for loop. If someone
wanted to set NR_EARLY_TIMERS = 0, this loop would still execute once, and would
not be the intended behavior.
> + struct omap_device *od;
> + struct omap_hwmod *oh;
> + int hw_mod_name_len = 16;
> + char oh_name[hw_mod_name_len];
s/hw_mod/hwmod/
> + struct omap_dm_timer_plat_info *pdata;
> +
> + snprintf(oh_name, hw_mod_name_len, "timer%d", i + 1);
> + oh = omap_hwmod_lookup(oh_name);
> + if (!oh)
> + break;
> +
> + pdata = kzalloc(sizeof(struct omap_dm_timer_plat_info),
> + GFP_KERNEL);
> + if (!pdata) {
> + pr_err("%s: Unable to allocate pdata for %s:%s\n",
> + __func__, name, oh->name);
> + return;
> + }
> +
> + pdata->omap_dm_clk_enable = omap2_dm_early_timer_enable;
> + pdata->omap_dm_clk_disable = omap2_dm_early_timer_disable;
> + pdata->omap_dm_set_source_clk = omap2_dm_early_timer_set_clk;
> + pdata->omap_dm_get_timer_clk = omap2_dm_early_timer_get_fclk;
> +
> + od = omap_device_build(name, i, oh, pdata, sizeof(*pdata),
> + omap2_dmtimer_latency,
> + ARRAY_SIZE(omap2_dmtimer_latency), 1);
> + if (IS_ERR(od)) {
> + pr_err("%s: Cant build omap_device for %s:%s.\n",
> + __func__, name, oh->name);
> + kfree(pdata);
> + }
> + i++;
> + } while (i < NO_EARLY_TIMERS);
> +
> + omap2_dm_timer_setup();
> + return;
> +}
Kevin
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