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55da97e38c
In clock driver initialize phase the spinlock is missed to assignment
to struct clkgate_separated, finally there have no locking to protect
exclusive accessing for clock registers.
This bug introduces the console has no output after enable coresight
driver on 96boards Hikey; this is because console using UART3, which
has shared the same register with coresight clock enabling bit. After
applied this patch it can assign lock properly to protect exclusive
accessing, and console can work well after enabled coresight modules.
Fixes: 0aa0c95f74 ("clk: hisilicon: add common clock support")
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
129 lines
3.6 KiB
C
129 lines
3.6 KiB
C
/*
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* Hisilicon clock separated gate driver
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*
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* Copyright (c) 2012-2013 Hisilicon Limited.
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* Copyright (c) 2012-2013 Linaro Limited.
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*
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* Author: Haojian Zhuang <haojian.zhuang@linaro.org>
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* Xin Li <li.xin@linaro.org>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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*/
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#include <linux/kernel.h>
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#include <linux/clk-provider.h>
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#include <linux/io.h>
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#include <linux/slab.h>
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#include "clk.h"
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/* clock separated gate register offset */
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#define CLKGATE_SEPERATED_ENABLE 0x0
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#define CLKGATE_SEPERATED_DISABLE 0x4
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#define CLKGATE_SEPERATED_STATUS 0x8
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struct clkgate_separated {
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struct clk_hw hw;
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void __iomem *enable; /* enable register */
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u8 bit_idx; /* bits in enable/disable register */
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u8 flags;
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spinlock_t *lock;
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};
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static int clkgate_separated_enable(struct clk_hw *hw)
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{
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struct clkgate_separated *sclk;
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unsigned long flags = 0;
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u32 reg;
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sclk = container_of(hw, struct clkgate_separated, hw);
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if (sclk->lock)
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spin_lock_irqsave(sclk->lock, flags);
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reg = BIT(sclk->bit_idx);
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writel_relaxed(reg, sclk->enable);
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readl_relaxed(sclk->enable + CLKGATE_SEPERATED_STATUS);
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if (sclk->lock)
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spin_unlock_irqrestore(sclk->lock, flags);
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return 0;
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}
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static void clkgate_separated_disable(struct clk_hw *hw)
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{
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struct clkgate_separated *sclk;
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unsigned long flags = 0;
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u32 reg;
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sclk = container_of(hw, struct clkgate_separated, hw);
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if (sclk->lock)
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spin_lock_irqsave(sclk->lock, flags);
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reg = BIT(sclk->bit_idx);
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writel_relaxed(reg, sclk->enable + CLKGATE_SEPERATED_DISABLE);
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readl_relaxed(sclk->enable + CLKGATE_SEPERATED_STATUS);
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if (sclk->lock)
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spin_unlock_irqrestore(sclk->lock, flags);
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}
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static int clkgate_separated_is_enabled(struct clk_hw *hw)
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{
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struct clkgate_separated *sclk;
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u32 reg;
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sclk = container_of(hw, struct clkgate_separated, hw);
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reg = readl_relaxed(sclk->enable + CLKGATE_SEPERATED_STATUS);
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reg &= BIT(sclk->bit_idx);
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return reg ? 1 : 0;
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}
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static struct clk_ops clkgate_separated_ops = {
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.enable = clkgate_separated_enable,
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.disable = clkgate_separated_disable,
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.is_enabled = clkgate_separated_is_enabled,
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};
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struct clk *hisi_register_clkgate_sep(struct device *dev, const char *name,
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const char *parent_name,
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unsigned long flags,
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void __iomem *reg, u8 bit_idx,
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u8 clk_gate_flags, spinlock_t *lock)
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{
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struct clkgate_separated *sclk;
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struct clk *clk;
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struct clk_init_data init;
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sclk = kzalloc(sizeof(*sclk), GFP_KERNEL);
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if (!sclk) {
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pr_err("%s: fail to allocate separated gated clk\n", __func__);
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return ERR_PTR(-ENOMEM);
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}
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init.name = name;
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init.ops = &clkgate_separated_ops;
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init.flags = flags | CLK_IS_BASIC;
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init.parent_names = (parent_name ? &parent_name : NULL);
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init.num_parents = (parent_name ? 1 : 0);
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sclk->enable = reg + CLKGATE_SEPERATED_ENABLE;
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sclk->bit_idx = bit_idx;
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sclk->flags = clk_gate_flags;
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sclk->hw.init = &init;
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sclk->lock = lock;
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clk = clk_register(dev, &sclk->hw);
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if (IS_ERR(clk))
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kfree(sclk);
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return clk;
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}
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