[PATCH v3 2/7] clocksource: sh_cmt: Add OF support

Bastian Hecht hechtb at gmail.com
Thu Apr 11 04:01:57 EDT 2013


Hi Simon,

2013/4/9 Bastian Hecht <hechtb at gmail.com>:
> Hi Simon,
>
> 2013/4/9 Simon Horman <horms at verge.net.au>:
>> On 木,  3月 21, 2013 at 10:07:15午後 +0900, Simon Horman wrote:
>>> On Sun, Mar 17, 2013 at 04:43:46PM +0100, Bastian Hecht wrote:
>>> > We add the capabilty to probe SH CMT timer devices using Device Tree
>>> > setup.
>>> >
>>> > Signed-off-by: Bastian Hecht <hechtb+renesas at gmail.com>
>>> > ---
>>> > v3: same (only patch 0003 changed)
>>> >
>>> >  drivers/clocksource/sh_cmt.c |  109 +++++++++++++++++++++++++++++++++++++-----
>>>
>>>
>>> This change appears to break booting of kzm9g-reference
>>> with MMC enabled. I assume because it somehow causes CMT to
>>> (once again) be initialised after SDHI and/or MMC.
>>>
>>> Tested using next with the defconfig + CONFIG_MACH_KZM9G_REFERENCE=y +
>>> initrd root fs.
>>
>
> Thanks for finding this flaw. I've got it on my agenda.
>
> Bastian
>
>>> >  1 file changed, 96 insertions(+), 13 deletions(-)
>>> >
>>> > diff --git a/drivers/clocksource/sh_cmt.c b/drivers/clocksource/sh_cmt.c
>>> > index 08d0c41..79bc526 100644
>>> > --- a/drivers/clocksource/sh_cmt.c
>>> > +++ b/drivers/clocksource/sh_cmt.c
>>> > @@ -34,10 +34,13 @@
>>> >  #include <linux/module.h>
>>> >  #include <linux/pm_domain.h>
>>> >  #include <linux/pm_runtime.h>
>>> > +#include <linux/of.h>
>>> >
>>> >  struct sh_cmt_priv {
>>> >     void __iomem *mapbase;
>>> >     struct clk *clk;
>>> > +   long channel_offset;
>>> > +   int timer_bit;
>>> >     unsigned long width; /* 16 or 32 bit version of hardware block */
>>> >     unsigned long overflow_bit;
>>> >     unsigned long clear_bits;
>>> > @@ -109,9 +112,7 @@ static void sh_cmt_write32(void __iomem *base, unsigned long offs,
>>> >
>>> >  static inline unsigned long sh_cmt_read_cmstr(struct sh_cmt_priv *p)
>>> >  {
>>> > -   struct sh_timer_config *cfg = p->pdev->dev.platform_data;
>>> > -
>>> > -   return p->read_control(p->mapbase - cfg->channel_offset, 0);
>>> > +   return p->read_control(p->mapbase - p->channel_offset, 0);
>>> >  }
>>> >
>>> >  static inline unsigned long sh_cmt_read_cmcsr(struct sh_cmt_priv *p)
>>> > @@ -127,9 +128,7 @@ static inline unsigned long sh_cmt_read_cmcnt(struct sh_cmt_priv *p)
>>> >  static inline void sh_cmt_write_cmstr(struct sh_cmt_priv *p,
>>> >                                   unsigned long value)
>>> >  {
>>> > -   struct sh_timer_config *cfg = p->pdev->dev.platform_data;
>>> > -
>>> > -   p->write_control(p->mapbase - cfg->channel_offset, 0, value);
>>> > +   p->write_control(p->mapbase - p->channel_offset, 0, value);
>>> >  }
>>> >
>>> >  static inline void sh_cmt_write_cmcsr(struct sh_cmt_priv *p,
>>> > @@ -176,7 +175,6 @@ static DEFINE_RAW_SPINLOCK(sh_cmt_lock);
>>> >
>>> >  static void sh_cmt_start_stop_ch(struct sh_cmt_priv *p, int start)
>>> >  {
>>> > -   struct sh_timer_config *cfg = p->pdev->dev.platform_data;
>>> >     unsigned long flags, value;
>>> >
>>> >     /* start stop register shared by multiple timer channels */
>>> > @@ -184,9 +182,9 @@ static void sh_cmt_start_stop_ch(struct sh_cmt_priv *p, int start)
>>> >     value = sh_cmt_read_cmstr(p);
>>> >
>>> >     if (start)
>>> > -           value |= 1 << cfg->timer_bit;
>>> > +           value |= 1 << p->timer_bit;
>>> >     else
>>> > -           value &= ~(1 << cfg->timer_bit);
>>> > +           value &= ~(1 << p->timer_bit);
>>> >
>>> >     sh_cmt_write_cmstr(p, value);
>>> >     raw_spin_unlock_irqrestore(&sh_cmt_lock, flags);
>>> > @@ -673,9 +671,85 @@ static int sh_cmt_register(struct sh_cmt_priv *p, char *name,
>>> >     return 0;
>>> >  }
>>> >
>>> > -static int sh_cmt_setup(struct sh_cmt_priv *p, struct platform_device *pdev)
>>> > +static const struct of_device_id of_sh_cmt_match[] = {
>>> > +   { .compatible = "renesas,cmt-timer" },
>>> > +   {},
>>> > +};
>>> > +MODULE_DEVICE_TABLE(of, of_sh_cmt_match);
>>> > +
>>> > +static const int sh_cmt_offset_multiplier[] = { 0x60, 0x10, 0x40, 0x40, 0x40 };
>>> > +#define CMT_MAX_CHANNELS   6
>>> > +
>>> > +static struct sh_timer_config *sh_cmt_parse_dt(struct device *dev)
>>> > +{
>>> > +   struct sh_timer_config *cfg;
>>> > +   struct device_node *np = dev->of_node;
>>> > +   u32 timer_id, channel_id, rating;
>>> > +
>>> > +   if (!IS_ENABLED(CONFIG_OF) || !np)
>>> > +           return NULL;
>>> > +
>>> > +   cfg = devm_kzalloc(dev, sizeof(struct sh_timer_config), GFP_KERNEL);
>>> > +   if (!cfg) {
>>> > +           dev_err(dev, "failed to allocate DT config data\n");
>>> > +           return NULL;
>>> > +   }
>>> > +
>>> > +   if (of_property_read_u32(np, "renesas,device-id", &timer_id)) {
>>> > +           dev_err(dev, "device id missing\n");
>>> > +           return NULL;
>>> > +   }
>>> > +   if (timer_id >= ARRAY_SIZE(sh_cmt_offset_multiplier)) {
>>> > +           dev_err(dev, "invalid device id\n");
>>> > +           return NULL;
>>> > +   }
>>> > +
>>> > +   if (of_property_read_u32(np, "renesas,channel-id", &channel_id)) {
>>> > +           dev_err(dev, "channel id missing\n");
>>> > +           return NULL;
>>> > +   }
>>> > +   if (channel_id >= CMT_MAX_CHANNELS) {
>>> > +           dev_err(dev, "invalid channel id\n");
>>> > +           return NULL;
>>> > +   }
>>> > +
>>> > +   cfg->channel_offset = sh_cmt_offset_multiplier[timer_id] *
>>> > +                                                   (channel_id + 1);
>>> > +   cfg->timer_bit = channel_id;
>>> > +
>>> > +   /*
>>> > +    * We convert the {source,event}-quality DT properties to linux specific
>>> > +    * clock{source,event}_ratings.
>>> > +    */
>>> > +   if (!of_property_read_u32(np, "renesas,source-quality", &rating)) {
>>> > +           if (rating > 10) {
>>> > +                   dev_err(dev, "invalid source-quality\n");
>>> > +                   return NULL;
>>> > +           }
>>> > +           if (rating)
>>> > +                   cfg->clocksource_rating = rating * 50 - 1;
>>> > +   }
>>> > +
>>> > +   if (!of_property_read_u32(np, "renesas,event-quality", &rating)) {
>>> > +           if (rating > 10) {
>>> > +                   dev_err(dev, "invalid event-quality\n");
>>> > +                   return NULL;
>>> > +           }
>>> > +           if (rating)
>>> > +                   cfg->clockevent_rating = rating * 50 - 1;
>>> > +   }
>>> > +
>>> > +   if (!cfg->clocksource_rating && !cfg->clockevent_rating) {
>>> > +           dev_err(dev, "source- and event-quality 0, timer is unused\n");
>>> > +           return NULL;
>>> > +   }
>>> > +
>>> > +   return cfg;
>>> > +}
>>> > +
>>> > +static int sh_cmt_setup(struct sh_cmt_priv *p, struct platform_device *pdev,
>>> > +                                           struct sh_timer_config *cfg)
>>> >  {
>>> > -   struct sh_timer_config *cfg = pdev->dev.platform_data;
>>> >     struct resource *res;
>>> >     int irq, ret;
>>> >     ret = -ENXIO;
>>> > @@ -762,6 +836,9 @@ static int sh_cmt_setup(struct sh_cmt_priv *p, struct platform_device *pdev)
>>> >             goto err2;
>>> >     }
>>> >
>>> > +   p->channel_offset = cfg->channel_offset;
>>> > +   p->timer_bit = cfg->timer_bit;
>>> > +

This happens too late. After interrupt registration. I have to check
the TMU patch as well and I'll send out a v4 later.

Thanks again for detecting this flaw.

Bastian


>>> >     platform_set_drvdata(pdev, p);
>>> >
>>> >     return 0;
>>> > @@ -777,7 +854,7 @@ err0:
>>> >  static int sh_cmt_probe(struct platform_device *pdev)
>>> >  {
>>> >     struct sh_cmt_priv *p = platform_get_drvdata(pdev);
>>> > -   struct sh_timer_config *cfg = pdev->dev.platform_data;
>>> > +   struct sh_timer_config *cfg;
>>> >     int ret;
>>> >
>>> >     if (!is_early_platform_device(pdev)) {
>>> > @@ -785,6 +862,11 @@ static int sh_cmt_probe(struct platform_device *pdev)
>>> >             pm_runtime_enable(&pdev->dev);
>>> >     }
>>> >
>>> > +   if (pdev->dev.of_node)
>>> > +           cfg = sh_cmt_parse_dt(&pdev->dev);
>>> > +   else
>>> > +           cfg = pdev->dev.platform_data;
>>> > +
>>> >     if (p) {
>>> >             dev_info(&pdev->dev, "kept as earlytimer\n");
>>> >             goto out;
>>> > @@ -796,7 +878,7 @@ static int sh_cmt_probe(struct platform_device *pdev)
>>> >             return -ENOMEM;
>>> >     }
>>> >
>>> > -   ret = sh_cmt_setup(p, pdev);
>>> > +   ret = sh_cmt_setup(p, pdev, cfg);
>>> >     if (ret) {
>>> >             kfree(p);
>>> >             pm_runtime_idle(&pdev->dev);
>>> > @@ -824,6 +906,7 @@ static struct platform_driver sh_cmt_device_driver = {
>>> >     .remove         = sh_cmt_remove,
>>> >     .driver         = {
>>> >             .name   = "sh_cmt",
>>> > +           .of_match_table = of_match_ptr(of_sh_cmt_match),
>>> >     }
>>> >  };
>>> >
>>> > --
>>> > 1.7.9.5
>>> >
>>> > --
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