linux-kernel - Re: [PATCH 3/8] regmap: Add support for using regmap over ssbi

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Date:	Thu, 12 Dec 2013 15:13:01 -0800
From:	Stephen Boyd <sboyd@...eaurora.org>
To:	Mark Brown <broonie@...nel.org>
CC:	Samuel Ortiz <sameo@...ux.intel.com>,
	Lee Jones <lee.jones@...aro.org>,
	Srinivas Ramana <sramana@...eaurora.org>,
	linux-kernel@...r.kernel.org, linux-arm-msm@...r.kernel.org,
	linux-arm-kernel@...ts.infradead.org
Subject: Re: [PATCH 3/8] regmap: Add support for using regmap over ssbi

On 12/11/13 05:27, Mark Brown wrote:
> On Tue, Dec 10, 2013 at 05:32:51PM -0800, Stephen Boyd wrote:
>
>> Are you suggesting we implement the reg_read/reg_write as global helpers
>> that the config points to and then call regmap_init()? At a quick glance
> Yes, assuming your bus really is limited in the way it seems from the
> code.

Ok, I'm happy to go the reg_read/reg_write way if we can have the
bulk_read and bulk_write operations work. I was trying to mimic the
regmap_mmio code because it seems to do the same things with respect to
bulk operations. Or perhaps this code should live in drivers/mfd/ssbi.c
and then we could return an error from the regmap_init call if
use_single_rw is false?

>
>> it looks like we lose out on regmap_bulk_read() if we do that. There is
>> one driver that will use regmap_bulk_read(), but I suppose we can just
> bulk_read() should decay to individual reads if there isn't a block
> operaton and it's not like the hardware actually supports bulk reads
> anyway.

So regmap_bulk_read() should work if I don't have a map->bus? To make it
work with reg_read/write I had to do this. I'm not sure how to make
bulk_write work.

diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index 9c021d9..1ccd61b 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -1897,14 +1897,10 @@ int regmap_bulk_read(struct regmap *map, unsigned int reg, void *val,
        size_t val_bytes = map->format.val_bytes;
        bool vol = regmap_volatile_range(map, reg, val_count);
 
-       if (!map->bus)
-               return -EINVAL;
-       if (!map->format.parse_inplace)
-               return -EINVAL;
        if (reg % map->reg_stride)
                return -EINVAL;
 
-       if (vol || map->cache_type == REGCACHE_NONE) {
+       if (map->bus && map->format.parse_inplace && (vol || map->cache_type == REGCACHE_NONE)) {
                /*
                 * Some devices does not support bulk read, for
                 * them we have a series of single read operations.

-- 
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