From a07bff4054c9e2b3a5c5790312a4a45aaeca7afe Mon Sep 17 00:00:00 2001 From: Mark Brown Date: Tue, 13 Jun 2023 21:17:43 +0100 Subject: [PATCH] regmap: Add a test case for write only registers Validate that attempts to read from write only registers fail and don't somehow trigger spurious hardware accesses. Signed-off-by: Mark Brown Link: https://lore.kernel.org/r/20230613-regmap-kunit-read-write-v1-2-2db337c52827@kernel.org Signed-off-by: Mark Brown --- drivers/base/regmap/regmap-kunit.c | 32 ++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) diff --git a/drivers/base/regmap/regmap-kunit.c b/drivers/base/regmap/regmap-kunit.c index f5c175022a477..a1a1a9ce2e13b 100644 --- a/drivers/base/regmap/regmap-kunit.c +++ b/drivers/base/regmap/regmap-kunit.c @@ -231,6 +231,37 @@ static void write_readonly(struct kunit *test) regmap_exit(map); } +static void read_writeonly(struct kunit *test) +{ + struct regcache_types *t = (struct regcache_types *)test->param_value; + struct regmap *map; + struct regmap_config config; + struct regmap_ram_data *data; + unsigned int val; + int i; + + config = test_regmap_config; + config.cache_type = t->type; + config.readable_reg = reg_5_false; + + map = gen_regmap(&config, &data); + KUNIT_ASSERT_FALSE(test, IS_ERR(map)); + if (IS_ERR(map)) + return; + + for (i = 0; i < BLOCK_TEST_SIZE; i++) + data->read[i] = false; + + /* Try to read all the registers, the writeonly one should fail */ + for (i = 0; i < BLOCK_TEST_SIZE; i++) + KUNIT_EXPECT_EQ(test, i != 5, regmap_read(map, i, &val) == 0); + + /* Did we trigger a hardware access? */ + KUNIT_EXPECT_FALSE(test, data->read[5]); + + regmap_exit(map); +} + static void reg_defaults(struct kunit *test) { struct regcache_types *t = (struct regcache_types *)test->param_value; @@ -1078,6 +1109,7 @@ static struct kunit_case regmap_test_cases[] = { KUNIT_CASE_PARAM(bulk_write, regcache_types_gen_params), KUNIT_CASE_PARAM(bulk_read, regcache_types_gen_params), KUNIT_CASE_PARAM(write_readonly, regcache_types_gen_params), + KUNIT_CASE_PARAM(read_writeonly, regcache_types_gen_params), KUNIT_CASE_PARAM(reg_defaults, regcache_types_gen_params), KUNIT_CASE_PARAM(reg_defaults_read_dev, regcache_types_gen_params), KUNIT_CASE_PARAM(register_patch, regcache_types_gen_params), -- 2.30.2