linux/drivers/clk/clkdev.c, branch v4.1

clk: Replace of_clk_get_by_clkspec() with of_clk_get_from_provider()

2015-03-12T19:20:34Z

of_clk_get_by_clkspec() has the same function signature as of_clk_get_from_provider() struct clk *of_clk_get_by_clkspec(struct of_phandle_args *clkspec) struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec) except of_clk_get_by_clkspec() checks to make sure clkspec is not NULL. Let's remove of_clk_get_by_clkspec() and replace the callers of it (clkconf.c) with of_clk_get_from_provider(). Cc: Sylwester Nawrocki Reviewed-by: Tomeu Vizoso Signed-off-by: Stephen Boyd

clkdev: Always allocate a struct clk and call __clk_get() w/ CCF

2015-02-07T01:53:20Z

of_clk_get_by_clkspec() returns a struct clk pointer but it doesn't create a new handle for the consumers when we're using the common clock framework. Instead it just returns whatever the clk provider hands out. When the consumers go to call clk_put() we get an Oops. Unable to handle kernel paging request at virtual address 00200200 pgd = c0004000 [00200200] *pgd=00000000 Internal error: Oops: 805 [#1] PREEMPT SMP ARM Modules linked in: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.19.0-rc1-00104-ga251361a-dirty #992 Hardware name: SAMSUNG EXYNOS (Flattened Device Tree) task: ee00b000 ti: ee088000 task.ti: ee088000 PC is at __clk_put+0x24/0xd0 LR is at clk_prepare_lock+0xc/0xec pc : [] lr : [] psr: 20000153 sp : ee089de8 ip : 00000000 fp : 00000000 r10: ee02f480 r9 : 00000001 r8 : 00000000 r7 : ee031cc0 r6 : ee089e08 r5 : 00000000 r4 : ee02f480 r3 : 00100100 r2 : 00200200 r1 : 0000091e r0 : 00000001 Flags: nzCv IRQs on FIQs off Mode SVC_32 ISA ARM Segment kernel Control: 10c5387d Table: 4000404a DAC: 00000015 Process swapper/0 (pid: 1, stack limit = 0xee088238) Stack: (0xee089de8 to 0xee08a000) 9de0: ee7c8f14 c03f0ec8 ee089e08 00000000 c0718dc8 00000001 9e00: 00000000 c04ee0f0 ee7e0844 00000001 00000181 c04edb58 ee2bd320 00000000 9e20: 00000000 c011dc5c ee16a1e0 00000000 00000000 c0718dc8 ee16a1e0 ee2bd1e0 9e40: c0641740 ee16a1e0 00000000 ee2bd320 c0718dc8 ee1d3e10 ee1d3e10 00000000 9e60: c0769a88 00000000 c0718dc8 00000000 00000000 c02c3124 c02c310c ee1d3e10 9e80: c07b4eec 00000000 c0769a88 c02c1d0c ee1d3e10 c0769a88 ee1d3e44 00000000 9ea0: c07091dc c02c1eb8 00000000 c0769a88 c02c1e2c c02c0544 ee005478 ee1676c0 9ec0: c0769a88 ee3a4e80 c0760ce8 c02c150c c0669b90 c0769a88 c0746cd8 c0769a88 9ee0: c0746cd8 ee2bc4c0 c0778c00 c02c24e0 00000000 c0746cd8 c0746cd8 c07091f0 9f00: 00000000 c0008944 c04f405c 00000025 ee00b000 60000153 c074ab00 00000000 9f20: 00000000 c074ab90 60000153 00000000 ef7fca5d c050860c 000000b6 c0036b88 9f40: c065ecc4 c06bc728 00000006 00000006 c074ab30 ef7fca40 c0739bdc 00000006 9f60: c0718dbc c0778c00 000000b6 c0718dc8 c06ed598 c06edd64 00000006 00000006 9f80: c06ed598 c003b438 00000000 c04e64f4 00000000 00000000 00000000 00000000 9fa0: 00000000 c04e64fc 00000000 c000e838 00000000 00000000 00000000 00000000 9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 9fe0: 00000000 00000000 00000000 00000000 00000013 00000000 c0c0c0c0 c0c0c0c0 [] (__clk_put) from [] (of_clk_set_defaults+0xe0/0x2c0) [] (of_clk_set_defaults) from [] (platform_drv_probe+0x18/0xa4) [] (platform_drv_probe) from [] (driver_probe_device+0x10c/0x22c) [] (driver_probe_device) from [] (__driver_attach+0x8c/0x90) [] (__driver_attach) from [] (bus_for_each_dev+0x54/0x88) [] (bus_for_each_dev) from [] (bus_add_driver+0xd4/0x1d0) [] (bus_add_driver) from [] (driver_register+0x78/0xf4) [] (driver_register) from [] (fimc_md_init+0x14/0x30) [] (fimc_md_init) from [] (do_one_initcall+0x80/0x1d0) [] (do_one_initcall) from [] (kernel_init_freeable+0x108/0x1d4) [] (kernel_init_freeable) from [] (kernel_init+0x8/0xec) [] (kernel_init) from [] (ret_from_fork+0x14/0x3c) Code: ebfff4ae e5943014 e5942018 e3530000 (e5823000) Let's create a per-user handle here so that clk_put() can properly unlink it and free the handle. Now that we allocate a clk structure here we need to free it if __clk_get() fails so bury the __clk_get() call in __of_clk_get_from_provider(). We need to handle the same problem in clk_get_sys() so export __clk_free_clk() to clkdev.c and do the same thing, except let's use a union to make this code #ifdef free. This fixes the above crash, properly calls __clk_get() when of_clk_get_from_provider() is called, and cleans up the clk structure on the error path of clk_get_sys(). Fixes: 035a61c314eb "clk: Make clk API return per-user struct clk instances" Reported-by: Sylwester Nawrocki Reported-by: Alban Browaeys Tested-by: Sylwester Nawrocki Tested-by: Alban Browaeys Reviewed-by: Tomeu Vizoso Signed-off-by: Stephen Boyd Signed-off-by: Michael Turquette

clkdev: Export clk_register_clkdev

2015-02-02T22:23:43Z

So it can be used from modules such as clk-test.ko. Signed-off-by: Tomeu Vizoso Reviewed-by: Stephen Boyd Signed-off-by: Michael Turquette

clk: Make clk API return per-user struct clk instances

2015-02-02T22:22:19Z

Moves clock state to struct clk_core, but takes care to change as little API as possible. struct clk_hw still has a pointer to a struct clk, which is the implementation's per-user clk instance, for backwards compatibility. The struct clk that clk_get_parent() returns isn't owned by the caller, but by the clock implementation, so the former shouldn't call clk_put() on it. Because some boards in mach-omap2 still register clocks statically, their clock registration had to be updated to take into account that the clock information is stored in struct clk_core now. Signed-off-by: Tomeu Vizoso Reviewed-by: Stephen Boyd Tested-by: Tony Lindgren Signed-off-by: Michael Turquette [mturquette@linaro.org: adapted clk_has_parent to struct clk_core applied OMAP3+ DPLL fix from Tero & Tony]

clkdev: Don't print errors on probe defer

2014-06-26T19:55:03Z

This error message can spam the logs if you have lots of probe deferals due to missing clocks. Just silence the error in this case because the driver should try again later. Signed-off-by: Stephen Boyd Acked-by: Russell King Signed-off-by: Mike Turquette

clk: Add of_clk_get_by_clkspec() helper

2014-05-22T22:54:59Z

This patch adds of_clk_get_by_clkspec() helper function, which does only a struct clk lookup from the clock providers. It is used in the subsequent patch where parsing of a clock from device tree and the lookup from providers needed to be split. Signed-off-by: Sylwester Nawrocki Signed-off-by: Mike Turquette

clk: return probe defer when DT clock not yet ready

2014-02-25T01:14:56Z

At probe time, a clock device may not be ready when some other device wants to use it. This patch lets the functions clk_get/devm_clk_get return a probe defer when the clock is defined in the DT but not yet available. Signed-off-by: Jean-Francois Moine Reviewed-by: Sylwester Nawrocki Tested-by: Sylwester Nawrocki Signed-off-by: Mike Turquette

clkdev: Fix race condition in clock lookup from device tree

2013-12-04T16:19:36Z

There is currently a race condition in the device tree part of clk_get() function, since the pointer returned from of_clk_get_by_name() may become invalid before __clk_get() call. E.g. due to the clock provider driver remove() callback being called in between of_clk_get_by_name() and __clk_get(). Fix this by doing both the look up and __clk_get() operations with the clock providers list mutex held. This ensures that the clock pointer returned from __of_clk_get_from_provider() call and passed to __clk_get() is valid, as long as the clock supplier module first removes its clock provider instance and then does clk_unregister() on the corresponding clocks. Signed-off-by: Sylwester Nawrocki Signed-off-by: Kyungmin Park Reviewed-by: Mike Turquette Acked-by: Russell King

ARM: 7534/1: clk: Make the managed clk functions generically available

2012-09-15T20:55:27Z

The managed clk functions are currently only available when the generic clk lookup framework is build. But the managed clk functions are merely wrappers around clk_get and clk_put and do not depend on any specifics of the generic lookup functions and there are still quite a few custom implementations of the clk API. So make the managed functions available whenever the clk API is implemented. The patch also removes the custom implementation of devm_clk_get for the coldfire platform. Signed-off-by: Lars-Peter Clausen Acked-by: Greg Ungerer Signed-off-by: Russell King

clk: fix compile for OF && !COMMON_CLK

2012-07-19T21:07:56Z

With commit 766e6a4ec602d0c107 (clk: add DT clock binding support), compiling with OF && !COMMON_CLK is broken. Reported-by: Alexandre Pereira da Silva Reported-by: Prashant Gaikwad Signed-off-by: Rob Herring Signed-off-by: Mike Turquette