![Javier Martinez Canillas](/assets/img/avatar_default.png)
The change in the clk API to return a per-user clock instance, moved
the clock state to struct clk_core so now the struct clk_hw .core field
is used instead of .clk for most operations.
So for hardware clocks that needs to share the same clock state, both
the .core and .clk pointers have to be assigned but currently only the
.clk is set. This leads to NULL pointer dereference when the operations
try to access the hw clock .core. For example, the composite clock rate
and mux components didn't have a .core set which leads to this error:
Unable to handle kernel NULL pointer dereference at virtual address 00000034
pgd = c0004000
[00000034] *pgd=00000000
Internal error: Oops: 5 [#1] PREEMPT SMP ARM
Modules linked in:
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.19.0-next-20150211-00002-g1fb7f0e1150d #423
Hardware name: SAMSUNG EXYNOS (Flattened Device Tree)
task: ee480000 ti: ee488000 task.ti: ee488000
PC is at clk_mux_determine_rate_flags+0x14/0x19c
LR is at __clk_mux_determine_rate+0x24/0x2c
pc : [<c03a355c>] lr : [<c03a3734>] psr: a0000113
sp : ee489ce8 ip : ee489d84 fp : ee489d84
r10: 0000005c r9 : 00000001 r8 : 016e3600
r7 : 00000000 r6 : 00000000 r5 : ee442200 r4 : ee440c98
r3 : ffffffff r2 : 00000000 r1 : 016e3600 r0 : ee440c98
Flags: NzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment kernel
Control: 10c5387d Table: 4000406a DAC: 00000015
Process swapper/0 (pid: 1, stack limit = 0xee488210)
Stack: (0xee489ce8 to 0xee48a000)
9ce0: 00000000 ffffffff 60000113 ee440c98 ee442200 00000000
9d00: 016e3600 ffffffff 00000001 0000005c ee489d84 c03a3734 ee489d80 ee489d84
9d20: 00000000 c048b130 00000400 c03a5798 ee489d80 ee489d84 c0607f60 ffffffea
9d40: 00000001 00000001 ee489d5c c003f844 c06e3340 ee402680 ee440d0c ed935000
9d60: 016e3600 00000003 00000001 0000005c eded3700 c03a11a0 ee489d80 ee489d84
9d80: 016e3600 ee402680 c05b413a eddc9900 016e3600 c03a1228 00000000 ffffffff
9da0: ffffffff eddc9900 016e3600 c03a1c1c ffffffff 016e3600 ed8c6710 c03d6ce4
9dc0: eded3400 00000000 00000000 c03c797c 00000001 0000005c eded3700 eded3700
9de0: 000005e0 00000001 0000005c c03db8ac c06e7e54 c03c8f08 00000000 c06e7e64
9e00: c06b6e74 c06e7f64 000005e0 c06e7df8 c06e5100 00000000 c06e7e6c c06e7f54
9e20: 00000000 00000000 eebd9550 00000000 c06e7da0 c06e7e54 ee7b5010 c06e7da0
9e40: eddc9690 c06e7db4 c06b6e74 00000097 00000000 c03d4398 00000000 ee7b5010
9e60: eebd9550 c06e7da0 00000000 c03db824 ee7b5010 fffffffe c06e7db4 c0299c7c
9e80: ee7b5010 c072a05c 00000000 c0298858 ee7b5010 c06e7db4 ee7b5044 00000000
9ea0: eddc9580 c0298a04 c06e7db4 00000000 c0298978 c02971d4 ee405c78 ee732b40
9ec0: c06e7db4 eded3800 c06d6738 c0298044 c0608300 c06e7db4 00000000 c06e7db4
9ee0: 00000000 c06beb58 c06beb58 c0299024 00000000 c068dd00 00000000 c0008944
9f00: 00000038 c049013c ee462200 c0711920 ee480000 60000113 c06c2cb0 00000000
9f20: 00000000 c06c2cb0 60000113 00000000 ef7fcafc 00000000 c0640194 c00389ec
9f40: c05ec3a8 c063f824 00000006 00000006 c06c2c50 c0696444 00000006 c0696424
9f60: c06ee1c0 c066b588 c06b6e74 00000097 00000000 c066bd44 00000006 00000006
9f80: c066b588 c003d684 00000000 c0481938 00000000 00000000 00000000 00000000
9fa0: 00000000 c0481940 00000000 c000e680 00000000 00000000 00000000 00000000
9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
9fe0: 00000000 00000000 00000000 00000000 00000013 00000000 00000000 00000000
[<c03a355c>] (clk_mux_determine_rate_flags) from [<c03a3734>] (__clk_mux_determine_rate+0x24/0x2c)
[<c03a3734>] (__clk_mux_determine_rate) from [<c03a5798>] (clk_composite_determine_rate+0xbc/0x238)
[<c03a5798>] (clk_composite_determine_rate) from [<c03a11a0>] (clk_core_round_rate_nolock+0x5c/0x9c)
[<c03a11a0>] (clk_core_round_rate_nolock) from [<c03a1228>] (__clk_round_rate+0x38/0x40)
[<c03a1228>] (__clk_round_rate) from [<c03a1c1c>] (clk_round_rate+0x20/0x38)
[<c03a1c1c>] (clk_round_rate) from [<c03d6ce4>] (max98090_dai_set_sysclk+0x34/0x118)
[<c03d6ce4>] (max98090_dai_set_sysclk) from [<c03c797c>] (snd_soc_dai_set_sysclk+0x38/0x80)
[<c03c797c>] (snd_soc_dai_set_sysclk) from [<c03db8ac>] (snow_late_probe+0x24/0x48)
[<c03db8ac>] (snow_late_probe) from [<c03c8f08>] (snd_soc_register_card+0xf04/0x1070)
[<c03c8f08>] (snd_soc_register_card) from [<c03d4398>] (devm_snd_soc_register_card+0x30/0x64)
[<c03d4398>] (devm_snd_soc_register_card) from [<c03db824>] (snow_probe+0x68/0xcc)
[<c03db824>] (snow_probe) from [<c0299c7c>] (platform_drv_probe+0x48/0x98)
[<c0299c7c>] (platform_drv_probe) from [<c0298858>] (driver_probe_device+0x114/0x234)
[<c0298858>] (driver_probe_device) from [<c0298a04>] (__driver_attach+0x8c/0x90)
[<c0298a04>] (__driver_attach) from [<c02971d4>] (bus_for_each_dev+0x54/0x88)
[<c02971d4>] (bus_for_each_dev) from [<c0298044>] (bus_add_driver+0xd8/0x1cc)
[<c0298044>] (bus_add_driver) from [<c0299024>] (driver_register+0x78/0xf4)
[<c0299024>] (driver_register) from [<c0008944>] (do_one_initcall+0x80/0x1d0)
[<c0008944>] (do_one_initcall) from [<c066bd44>] (kernel_init_freeable+0x10c/0x1d8)
[<c066bd44>] (kernel_init_freeable) from [<c0481940>] (kernel_init+0x8/0xe4)
[<c0481940>] (kernel_init) from [<c000e680>] (ret_from_fork+0x14/0x34)
Code: e24dd00c e5907000 e1a08001 e88d000c (e5970034)
The changes were made using the following cocinelle semantic patch:
@i@
@@
@depends on i@
identifier dst;
@@
- dst->clk = hw->clk;
+ __clk_hw_set_clk(dst, hw);
@depends on i@
identifier dst;
@@
- dst->hw.clk = hw->clk;
+ __clk_hw_set_clk(&dst->hw, hw);
Fixes: 035a61c314
("clk: Make clk API return per-user struct clk instances")
Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
343 lines
7.8 KiB
C
343 lines
7.8 KiB
C
/*
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* clk-flexgen.c
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*
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* Copyright (C) ST-Microelectronics SA 2013
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* Author: Maxime Coquelin <maxime.coquelin@st.com> for ST-Microelectronics.
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* License terms: GNU General Public License (GPL), version 2 */
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#include <linux/clk-provider.h>
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/io.h>
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#include <linux/err.h>
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#include <linux/string.h>
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#include <linux/of.h>
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#include <linux/of_address.h>
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struct flexgen {
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struct clk_hw hw;
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/* Crossbar */
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struct clk_mux mux;
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/* Pre-divisor's gate */
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struct clk_gate pgate;
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/* Pre-divisor */
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struct clk_divider pdiv;
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/* Final divisor's gate */
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struct clk_gate fgate;
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/* Final divisor */
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struct clk_divider fdiv;
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};
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#define to_flexgen(_hw) container_of(_hw, struct flexgen, hw)
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static int flexgen_enable(struct clk_hw *hw)
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{
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struct flexgen *flexgen = to_flexgen(hw);
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struct clk_hw *pgate_hw = &flexgen->pgate.hw;
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struct clk_hw *fgate_hw = &flexgen->fgate.hw;
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__clk_hw_set_clk(pgate_hw, hw);
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__clk_hw_set_clk(fgate_hw, hw);
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clk_gate_ops.enable(pgate_hw);
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clk_gate_ops.enable(fgate_hw);
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pr_debug("%s: flexgen output enabled\n", __clk_get_name(hw->clk));
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return 0;
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}
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static void flexgen_disable(struct clk_hw *hw)
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{
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struct flexgen *flexgen = to_flexgen(hw);
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struct clk_hw *fgate_hw = &flexgen->fgate.hw;
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/* disable only the final gate */
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__clk_hw_set_clk(fgate_hw, hw);
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clk_gate_ops.disable(fgate_hw);
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pr_debug("%s: flexgen output disabled\n", __clk_get_name(hw->clk));
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}
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static int flexgen_is_enabled(struct clk_hw *hw)
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{
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struct flexgen *flexgen = to_flexgen(hw);
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struct clk_hw *fgate_hw = &flexgen->fgate.hw;
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__clk_hw_set_clk(fgate_hw, hw);
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if (!clk_gate_ops.is_enabled(fgate_hw))
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return 0;
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return 1;
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}
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static u8 flexgen_get_parent(struct clk_hw *hw)
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{
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struct flexgen *flexgen = to_flexgen(hw);
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struct clk_hw *mux_hw = &flexgen->mux.hw;
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__clk_hw_set_clk(mux_hw, hw);
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return clk_mux_ops.get_parent(mux_hw);
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}
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static int flexgen_set_parent(struct clk_hw *hw, u8 index)
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{
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struct flexgen *flexgen = to_flexgen(hw);
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struct clk_hw *mux_hw = &flexgen->mux.hw;
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__clk_hw_set_clk(mux_hw, hw);
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return clk_mux_ops.set_parent(mux_hw, index);
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}
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static inline unsigned long
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clk_best_div(unsigned long parent_rate, unsigned long rate)
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{
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return parent_rate / rate + ((rate > (2*(parent_rate % rate))) ? 0 : 1);
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}
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static long flexgen_round_rate(struct clk_hw *hw, unsigned long rate,
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unsigned long *prate)
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{
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unsigned long div;
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/* Round div according to exact prate and wished rate */
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div = clk_best_div(*prate, rate);
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if (__clk_get_flags(hw->clk) & CLK_SET_RATE_PARENT) {
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*prate = rate * div;
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return rate;
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}
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return *prate / div;
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}
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unsigned long flexgen_recalc_rate(struct clk_hw *hw,
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unsigned long parent_rate)
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{
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struct flexgen *flexgen = to_flexgen(hw);
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struct clk_hw *pdiv_hw = &flexgen->pdiv.hw;
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struct clk_hw *fdiv_hw = &flexgen->fdiv.hw;
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unsigned long mid_rate;
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__clk_hw_set_clk(pdiv_hw, hw);
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__clk_hw_set_clk(fdiv_hw, hw);
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mid_rate = clk_divider_ops.recalc_rate(pdiv_hw, parent_rate);
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return clk_divider_ops.recalc_rate(fdiv_hw, mid_rate);
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}
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static int flexgen_set_rate(struct clk_hw *hw, unsigned long rate,
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unsigned long parent_rate)
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{
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struct flexgen *flexgen = to_flexgen(hw);
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struct clk_hw *pdiv_hw = &flexgen->pdiv.hw;
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struct clk_hw *fdiv_hw = &flexgen->fdiv.hw;
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unsigned long div = 0;
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int ret = 0;
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__clk_hw_set_clk(pdiv_hw, hw);
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__clk_hw_set_clk(fdiv_hw, hw);
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div = clk_best_div(parent_rate, rate);
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/*
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* pdiv is mainly targeted for low freq results, while fdiv
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* should be used for div <= 64. The other way round can
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* lead to 'duty cycle' issues.
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*/
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if (div <= 64) {
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clk_divider_ops.set_rate(pdiv_hw, parent_rate, parent_rate);
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ret = clk_divider_ops.set_rate(fdiv_hw, rate, rate * div);
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} else {
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clk_divider_ops.set_rate(fdiv_hw, parent_rate, parent_rate);
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ret = clk_divider_ops.set_rate(pdiv_hw, rate, rate * div);
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}
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return ret;
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}
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static const struct clk_ops flexgen_ops = {
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.enable = flexgen_enable,
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.disable = flexgen_disable,
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.is_enabled = flexgen_is_enabled,
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.get_parent = flexgen_get_parent,
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.set_parent = flexgen_set_parent,
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.round_rate = flexgen_round_rate,
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.recalc_rate = flexgen_recalc_rate,
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.set_rate = flexgen_set_rate,
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};
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struct clk *clk_register_flexgen(const char *name,
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const char **parent_names, u8 num_parents,
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void __iomem *reg, spinlock_t *lock, u32 idx,
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unsigned long flexgen_flags) {
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struct flexgen *fgxbar;
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struct clk *clk;
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struct clk_init_data init;
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u32 xbar_shift;
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void __iomem *xbar_reg, *fdiv_reg;
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fgxbar = kzalloc(sizeof(struct flexgen), GFP_KERNEL);
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if (!fgxbar)
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return ERR_PTR(-ENOMEM);
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init.name = name;
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init.ops = &flexgen_ops;
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init.flags = CLK_IS_BASIC | flexgen_flags;
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init.parent_names = parent_names;
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init.num_parents = num_parents;
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xbar_reg = reg + 0x18 + (idx & ~0x3);
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xbar_shift = (idx % 4) * 0x8;
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fdiv_reg = reg + 0x164 + idx * 4;
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/* Crossbar element config */
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fgxbar->mux.lock = lock;
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fgxbar->mux.mask = BIT(6) - 1;
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fgxbar->mux.reg = xbar_reg;
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fgxbar->mux.shift = xbar_shift;
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fgxbar->mux.table = NULL;
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/* Pre-divider's gate config (in xbar register)*/
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fgxbar->pgate.lock = lock;
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fgxbar->pgate.reg = xbar_reg;
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fgxbar->pgate.bit_idx = xbar_shift + 6;
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/* Pre-divider config */
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fgxbar->pdiv.lock = lock;
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fgxbar->pdiv.reg = reg + 0x58 + idx * 4;
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fgxbar->pdiv.width = 10;
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/* Final divider's gate config */
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fgxbar->fgate.lock = lock;
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fgxbar->fgate.reg = fdiv_reg;
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fgxbar->fgate.bit_idx = 6;
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/* Final divider config */
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fgxbar->fdiv.lock = lock;
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fgxbar->fdiv.reg = fdiv_reg;
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fgxbar->fdiv.width = 6;
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fgxbar->hw.init = &init;
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clk = clk_register(NULL, &fgxbar->hw);
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if (IS_ERR(clk))
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kfree(fgxbar);
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else
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pr_debug("%s: parent %s rate %u\n",
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__clk_get_name(clk),
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__clk_get_name(clk_get_parent(clk)),
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(unsigned int)clk_get_rate(clk));
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return clk;
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}
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static const char ** __init flexgen_get_parents(struct device_node *np,
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int *num_parents)
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{
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const char **parents;
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int nparents, i;
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nparents = of_count_phandle_with_args(np, "clocks", "#clock-cells");
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if (WARN_ON(nparents <= 0))
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return NULL;
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parents = kcalloc(nparents, sizeof(const char *), GFP_KERNEL);
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if (!parents)
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return NULL;
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for (i = 0; i < nparents; i++)
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parents[i] = of_clk_get_parent_name(np, i);
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*num_parents = nparents;
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return parents;
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}
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void __init st_of_flexgen_setup(struct device_node *np)
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{
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struct device_node *pnode;
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void __iomem *reg;
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struct clk_onecell_data *clk_data;
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const char **parents;
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int num_parents, i;
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spinlock_t *rlock = NULL;
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unsigned long flex_flags = 0;
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pnode = of_get_parent(np);
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if (!pnode)
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return;
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reg = of_iomap(pnode, 0);
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if (!reg)
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return;
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parents = flexgen_get_parents(np, &num_parents);
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if (!parents)
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return;
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clk_data = kzalloc(sizeof(*clk_data), GFP_KERNEL);
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if (!clk_data)
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goto err;
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clk_data->clk_num = of_property_count_strings(np ,
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"clock-output-names");
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if (clk_data->clk_num <= 0) {
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pr_err("%s: Failed to get number of output clocks (%d)",
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__func__, clk_data->clk_num);
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goto err;
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}
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clk_data->clks = kcalloc(clk_data->clk_num, sizeof(struct clk *),
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GFP_KERNEL);
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if (!clk_data->clks)
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goto err;
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rlock = kzalloc(sizeof(spinlock_t), GFP_KERNEL);
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if (!rlock)
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goto err;
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for (i = 0; i < clk_data->clk_num; i++) {
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struct clk *clk;
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const char *clk_name;
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if (of_property_read_string_index(np, "clock-output-names",
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i, &clk_name)) {
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break;
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}
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/*
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* If we read an empty clock name then the output is unused
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*/
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if (*clk_name == '\0')
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continue;
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clk = clk_register_flexgen(clk_name, parents, num_parents,
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reg, rlock, i, flex_flags);
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if (IS_ERR(clk))
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goto err;
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clk_data->clks[i] = clk;
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}
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kfree(parents);
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of_clk_add_provider(np, of_clk_src_onecell_get, clk_data);
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return;
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err:
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if (clk_data)
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kfree(clk_data->clks);
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kfree(clk_data);
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kfree(parents);
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kfree(rlock);
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}
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CLK_OF_DECLARE(flexgen, "st,flexgen", st_of_flexgen_setup);
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