From 8985167ecf57f97061599a155bb9652c84ea4913 Mon Sep 17 00:00:00 2001 From: Krzysztof Kozlowski Date: Wed, 29 Aug 2018 21:20:10 +0200 Subject: clk: s2mps11: Fix matching when built as module and DT node contains compatible When driver is built as module and DT node contains clocks compatible (e.g. "samsung,s2mps11-clk"), the module will not be autoloaded because module aliases won't match. The modalias from uevent: of:NclocksTCsamsung,s2mps11-clk The modalias from driver: platform:s2mps11-clk The devices are instantiated by parent's MFD. However both Device Tree bindings and parent define the compatible for clocks devices. In case of module matching this DT compatible will be used. The issue will not happen if this is a built-in (no need for module matching) or when clocks DT node does not contain compatible (not correct from bindings perspective but working for driver). Note when backporting to stable kernels: adjust the list of device ID entries. Cc: Fixes: 53c31b3437a6 ("mfd: sec-core: Add of_compatible strings for clock MFD cells") Signed-off-by: Krzysztof Kozlowski Acked-by: Stephen Boyd Signed-off-by: Stephen Boyd --- drivers/clk/clk-s2mps11.c | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) (limited to 'drivers/clk/clk-s2mps11.c') diff --git a/drivers/clk/clk-s2mps11.c b/drivers/clk/clk-s2mps11.c index d44e0eea31ec..0934d3724495 100644 --- a/drivers/clk/clk-s2mps11.c +++ b/drivers/clk/clk-s2mps11.c @@ -245,6 +245,36 @@ static const struct platform_device_id s2mps11_clk_id[] = { }; MODULE_DEVICE_TABLE(platform, s2mps11_clk_id); +#ifdef CONFIG_OF +/* + * Device is instantiated through parent MFD device and device matching is done + * through platform_device_id. + * + * However if device's DT node contains proper clock compatible and driver is + * built as a module, then the *module* matching will be done trough DT aliases. + * This requires of_device_id table. In the same time this will not change the + * actual *device* matching so do not add .of_match_table. + */ +static const struct of_device_id s2mps11_dt_match[] = { + { + .compatible = "samsung,s2mps11-clk", + .data = (void *)S2MPS11X, + }, { + .compatible = "samsung,s2mps13-clk", + .data = (void *)S2MPS13X, + }, { + .compatible = "samsung,s2mps14-clk", + .data = (void *)S2MPS14X, + }, { + .compatible = "samsung,s5m8767-clk", + .data = (void *)S5M8767X, + }, { + /* Sentinel */ + }, +}; +MODULE_DEVICE_TABLE(of, s2mps11_dt_match); +#endif + static struct platform_driver s2mps11_clk_driver = { .driver = { .name = "s2mps11-clk", -- cgit v1.2.1 From 9c940bbe2bb47e03ca5e937d30b6a50bf9c0e671 Mon Sep 17 00:00:00 2001 From: Nathan Chancellor Date: Thu, 18 Oct 2018 12:13:40 -0700 Subject: clk: s2mps11: Add used attribute to s2mps11_dt_match Clang warns after commit 8985167ecf57 ("clk: s2mps11: Fix matching when built as module and DT node contains compatible"): drivers/clk/clk-s2mps11.c:242:34: warning: variable 's2mps11_dt_match' is not needed and will not be emitted [-Wunneeded-internal-declaration] static const struct of_device_id s2mps11_dt_match[] = { ^ 1 warning generated. This warning happens when a variable is used in some construct that doesn't require a reference to that variable to be emitted in the symbol table; in this case, it's MODULE_DEVICE_TABLE, which only needs to hold the data of the variable, not the variable itself. $ nm -S drivers/clk/clk-s2mps11.o | rg s2mps11_dt_match 00000078 000003d4 R __mod_of__s2mps11_dt_match_device_table Normally, with device ID table variables, it means that the variable just needs to be tied to the device declaration at the bottom of the file, like s2mps11_clk_id: $ nm -S drivers/clk/clk-s2mps11.o | rg s2mps11_clk_id 00000000 00000078 R __mod_platform__s2mps11_clk_id_device_table 00000000 00000078 r s2mps11_clk_id However, because the comment above this deliberately doesn't want this variable added to .of_match_table, we need to mark s2mps11_dt_match as __used to silence this warning. This makes it clear to Clang that the variable is used for something, even if a reference to it isn't being emitted. Signed-off-by: Nathan Chancellor Fixes: 8985167ecf57 ("clk: s2mps11: Fix matching when built as module and DT node contains compatible") Signed-off-by: Stephen Boyd --- drivers/clk/clk-s2mps11.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/clk/clk-s2mps11.c') diff --git a/drivers/clk/clk-s2mps11.c b/drivers/clk/clk-s2mps11.c index 0934d3724495..4080d4e78e8e 100644 --- a/drivers/clk/clk-s2mps11.c +++ b/drivers/clk/clk-s2mps11.c @@ -255,7 +255,7 @@ MODULE_DEVICE_TABLE(platform, s2mps11_clk_id); * This requires of_device_id table. In the same time this will not change the * actual *device* matching so do not add .of_match_table. */ -static const struct of_device_id s2mps11_dt_match[] = { +static const struct of_device_id s2mps11_dt_match[] __used = { { .compatible = "samsung,s2mps11-clk", .data = (void *)S2MPS11X, -- cgit v1.2.1