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>
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>
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>
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>
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>
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>
Tero Kristo