Commit Graph

17 Commits

Author SHA1 Message Date
Arnd Bergmann 3417f3528a clk: ti: divider: try to fix ti_clk_register_divider
Commit 6c0afb5039 ("clk: ti: convert to use proper register
definition for all accesses") converted all register accesses in
the TI clk driver to use a proper struct instead of a void
pointer casted struct that fits into a u32. Unfortunately, it
missed a conversion here in the didivder code, leading to a
compiler warning like so:

drivers/clk/ti/divider.c: In function 'ti_clk_register_divider':
drivers/clk/ti/divider.c:460:8: error: 'reg' may be used uninitialized in this function [-Werror=maybe-uninitialized]

Treating a 'u32' variable as a structure leads to a stack
overflow here, and the register address we pass down is never
initialized. Convert this part of the code as well so things
work properly.

Fixes: 6c0afb5039 ("clk: ti: convert to use proper register definition for all accesses")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
[sboyd@codeaurora.org: Fixed fixes tag, rewrote commit message,
s/reg_setup/reg/]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2017-04-28 11:07:09 -07:00
Tero Kristo 6c0afb5039 clk: ti: convert to use proper register definition for all accesses
Currently, TI clock driver uses an encapsulated struct that is cast into
a void pointer to store all register addresses. This can be considered
as rather nasty hackery, and prevents from expanding the register
address field also. Instead, replace all the code to use proper struct
in place for this, which contains all the previously used data.

This patch is rather large as it is touching multiple files, but this
can't be split up as we need to avoid any boot breakage.

Signed-off-by: Tero Kristo <t-kristo@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
2017-03-08 13:06:15 +02:00
Tero Kristo 4f6be5655d clk: ti: divider: add driver internal API for parsing divider data
This can be used from the divider itself, and also from the clkctrl
clocks once this is introduced.

Signed-off-by: Tero Kristo <t-kristo@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
2017-03-08 13:04:38 +02:00
Tero Kristo 6dbde94756 clk: ti: divider: convert TI divider clock to use its own data representation
Instead of using the generic clock driver data struct, use one internal
for the TI clock driver itself. This allows modifying the register access
parts in subsequent patch.

Signed-off-by: Tero Kristo <t-kristo@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
2017-03-08 13:04:06 +02:00
Tero Kristo 1ae79c46cf clk: ti: use automatic clock alias generation framework
Generate clock aliases automatically for all TI clock drivers.

Signed-off-by: Tero Kristo <t-kristo@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
2017-03-08 12:58:18 +02:00
Keerthy ced3068344 clk: ti: divider: Add the table parsing to get the best divider value
Currently the divider selection logic blindly divides the parent_rate
by the clk rate and gives the divider value for the divider clocks
which do not have the CLK_SET_RATE_PARENT flag set. Add the clk divider
table parsing to get the closest divider available in the table
provided via Device tree.

The code is pretty much taken from: drivers/clk/clk-divider.c.
and used here to fix up the best divider selection logic.

Signed-off-by: Keerthy <j-keerthy@ti.com>
Reported-by: Richard Woodruff <r-woodruff2@ti.com>
Acked-by: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2017-01-26 16:03:04 -08:00
Geliang Tang 5fd9c05c84 clk: move the common clock's to_clk_*(_hw) macros to clk-provider.h
to_clk_*(_hw) macros have been repeatedly defined in many places.
This patch moves all the to_clk_*(_hw) definitions in the common
clock framework to public header clk-provider.h, and drop the local
definitions.

Signed-off-by: Geliang Tang <geliangtang@163.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-01-29 12:59:50 -08:00
Grygorii Strashko 167af5ef2c clk: ti: drop locking code from mux/divider drivers
TI's mux and divider clock drivers do not require locking and they do
not initialize internal spinlocks. This code was occasionally
copy-posted from generic mux/divider drivers. So remove it.

Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Tero Kristo <t-kristo@ti.com>
2015-11-24 11:30:27 +02:00
Stephen Boyd a53ad8ef3d clk: ti: Convert to clk_hw based provider APIs
We're removing struct clk from the clk provider API, so switch
this code to using the clk_hw based provider APIs.

Acked-by: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-08-24 16:48:58 -07:00
Stephen Boyd 98d8a60ecc clk: Convert __clk_get_flags() to clk_hw_get_flags()
Mostly converted with the following snippet:

@@
struct clk_hw *E;
@@

-__clk_get_flags(E->clk)
+clk_hw_get_flags(E)

Acked-by: Tero Kristo <t-kristo@ti.com>
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Acked-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Coquelin <mcoquelin.stm32@gmail.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-08-24 16:48:44 -07:00
Tero Kristo c807dbedb5 clk: ti: fix ti_clk_get_reg_addr error handling
There is a case where NULL can be a valid return value for
ti_clk_get_reg_addr, specifically the case where both the provider index
and register offsets are zero. In this case, the current error checking
against a NULL pointer will fail. Thus, change the API to return a
ERR_PTR value in an error case, and change all the users of this API to
check against IS_ERR instead.

Signed-off-by: Tero Kristo <t-kristo@ti.com>
Acked-by: Michael Turquette <mturquette@linaro.org>
2015-03-24 20:23:36 +02:00
Tero Kristo d96f774b25 clk: ti: divider: add support for legacy divider init
Legacy clock data is initialized slightly differently compared to
DT clocks, thus add support for this.

Signed-off-by: Tero Kristo <t-kristo@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
2015-01-30 10:55:05 -08:00
Mike Turquette 82de1bc86c Merge branch 'for-v3.18/ti-clk-driver' of github.com:t-kristo/linux-pm into clk-next 2014-09-29 23:38:59 -07:00
Behan Webster e8627a9ec3 clk: ti: LLVMLinux: Move __init outside of type definition
As written, the __init for ti_clk_get_div_table is in the middle of the return
type.

The gcc documentation indicates that section attributes should be added to the
end of the function declaration:

  extern void foobar (void) __attribute__ ((section ("bar")));

However gcc seems to be very permissive with where attributes can be placed.
clang on the other hand isn't so permissive, and fails if you put the section
definition in the middle of the return type:

drivers/clk/ti/divider.c:298:28: error: expected ';' after struct
static struct clk_div_table
                           ^
                           ;
drivers/clk/ti/divider.c:298:1: warning: 'static' ignored on this
      declaration [-Wmissing-declarations]
static struct clk_div_table
^
drivers/clk/ti/divider.c:299:9: error: type specifier missing,
      defaults to 'int' [-Werror,-Wimplicit-int]
__init *ti_clk_get_div_table(struct device_node *node)
~~~~~~  ^
drivers/clk/ti/divider.c:345:9: warning: incompatible pointer types
      returning 'struct clk_div_table *' from a function with result type 'int *' [-Wincompatible-pointer-types]
        return table;
               ^~~~~
drivers/clk/ti/divider.c:419:9: warning: incompatible pointer types
      assigning to 'const struct clk_div_table *' from 'int *' [-Wincompatible-pointer-types]
        *table = ti_clk_get_div_table(node);
               ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~
3 warnings and 2 errors generated.

By convention, most of the kernel code puts section attributes between the
return type and function name. In the case where the return type is a pointer,
it's important to place the '*' on left of the __init.

This updated code works for both gcc and clang.

Signed-off-by: Behan Webster <behanw@converseincode.com>
Reviewed-by: Mark Charlebois <charlebm@gmail.com>
Reviewed-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Tero Kristo <t-kristo@ti.com>
2014-09-29 11:51:14 +03:00
Nishanth Menon 2f10325176 clk: ti: divider: Provide error check for incoming parameters in set_rate
Check for valid parameters in check rate. Else, we end up getting errors
like:
[    0.000000] Division by zero in kernel.
[    0.000000] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.17.0-rc1 #1
[    0.000000] [<c0015160>] (unwind_backtrace) from [<c0011978>] (show_stack+0x10/0x14)
[    0.000000] [<c0011978>] (show_stack) from [<c055f5f4>] (dump_stack+0x78/0x94)
[    0.000000] [<c055f5f4>] (dump_stack) from [<c02e17cc>] (Ldiv0+0x8/0x10)
[    0.000000] [<c02e17cc>] (Ldiv0) from [<c047d228>] (ti_clk_divider_set_rate+0x14/0x14c)
[    0.000000] [<c047d228>] (ti_clk_divider_set_rate) from [<c047a938>] (clk_change_rate+0x138/0x180)
[    0.000000] [<c047a938>] (clk_change_rate) from [<c047a908>] (clk_change_rate+0x108/0x180)

This occurs as part of the inital clock tree update of child clock nodes
where new_rate could be 0 for non functional clocks.

Fixes: b4761198bf ("CLK: ti: add support for ti divider-clock")
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Tero Kristo <t-kristo@ti.com>
2014-08-21 18:04:16 +03:00
Tomi Valkeinen 7e50e7e176 clk: ti/divider: fix rate calculation for fractional rates
ti/clk-divider.c does not calculate the rates consistently at the moment.

As an example, on OMAP3 we have a clock divider with a source clock of
864000000 Hz. With dividers 6, 7 and 8 the theoretical rates are:

6: 144000000
7: 123428571.428571...
8: 108000000

Calling clk_round_rate() with the rate in the first column will give the
rate in the second column:

144000000 -> 144000000
143999999 -> 123428571
123428572 -> 123428571
123428571 -> 108000000

Note how clk_round_rate() returns 123428571 for rates from 123428572 to
143999999, which is mathematically correct, but when clk_round_rate() is
called with 123428571, the returned value is surprisingly 108000000.

This means that the following code works a bit oddly:

rate = clk_round_rate(clk, 123428572);
clk_set_rate(clk, rate);

As clk_set_rate() also does clock rate rounding, the result is that the
clock is set to the rate of 108000000, not 123428571 returned by the
clk_round_rate.

This patch changes the ti/clk-divider.c to use DIV_ROUND_UP when
calculating the rate. This gives the following behavior which fixes the
inconsistency:

144000000 -> 144000000
143999999 -> 123428572
123428572 -> 123428572
123428571 -> 108000000

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2014-02-26 18:23:58 -08:00
Tero Kristo b4761198bf CLK: ti: add support for ti divider-clock
This patch adds support for TI divider clock binding, which simply uses
the basic clock divider to provide the features needed.

Signed-off-by: Tero Kristo <t-kristo@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
2014-01-17 12:35:04 -08:00