diff options
Diffstat (limited to '')
-rw-r--r-- | drivers/clk/imx/clk-lpcg-scu.c | 163 |
1 files changed, 163 insertions, 0 deletions
diff --git a/drivers/clk/imx/clk-lpcg-scu.c b/drivers/clk/imx/clk-lpcg-scu.c new file mode 100644 index 000000000..dd5abd09f --- /dev/null +++ b/drivers/clk/imx/clk-lpcg-scu.c @@ -0,0 +1,163 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright 2018 NXP + * Dong Aisheng <aisheng.dong@nxp.com> + */ + +#include <linux/bits.h> +#include <linux/clk-provider.h> +#include <linux/err.h> +#include <linux/io.h> +#include <linux/slab.h> +#include <linux/spinlock.h> + +#include "clk-scu.h" + +static DEFINE_SPINLOCK(imx_lpcg_scu_lock); + +#define CLK_GATE_SCU_LPCG_MASK 0x3 +#define CLK_GATE_SCU_LPCG_HW_SEL BIT(0) +#define CLK_GATE_SCU_LPCG_SW_SEL BIT(1) + +/* + * struct clk_lpcg_scu - Description of LPCG clock + * + * @hw: clk_hw of this LPCG + * @reg: register of this LPCG clock + * @bit_idx: bit index of this LPCG clock + * @hw_gate: HW auto gate enable + * + * This structure describes one LPCG clock + */ +struct clk_lpcg_scu { + struct clk_hw hw; + void __iomem *reg; + u8 bit_idx; + bool hw_gate; + + /* for state save&restore */ + u32 state; +}; + +#define to_clk_lpcg_scu(_hw) container_of(_hw, struct clk_lpcg_scu, hw) + +static int clk_lpcg_scu_enable(struct clk_hw *hw) +{ + struct clk_lpcg_scu *clk = to_clk_lpcg_scu(hw); + unsigned long flags; + u32 reg, val; + + spin_lock_irqsave(&imx_lpcg_scu_lock, flags); + + reg = readl_relaxed(clk->reg); + reg &= ~(CLK_GATE_SCU_LPCG_MASK << clk->bit_idx); + + val = CLK_GATE_SCU_LPCG_SW_SEL; + if (clk->hw_gate) + val |= CLK_GATE_SCU_LPCG_HW_SEL; + + reg |= val << clk->bit_idx; + writel(reg, clk->reg); + + spin_unlock_irqrestore(&imx_lpcg_scu_lock, flags); + + return 0; +} + +static void clk_lpcg_scu_disable(struct clk_hw *hw) +{ + struct clk_lpcg_scu *clk = to_clk_lpcg_scu(hw); + unsigned long flags; + u32 reg; + + spin_lock_irqsave(&imx_lpcg_scu_lock, flags); + + reg = readl_relaxed(clk->reg); + reg &= ~(CLK_GATE_SCU_LPCG_MASK << clk->bit_idx); + writel(reg, clk->reg); + + spin_unlock_irqrestore(&imx_lpcg_scu_lock, flags); +} + +static const struct clk_ops clk_lpcg_scu_ops = { + .enable = clk_lpcg_scu_enable, + .disable = clk_lpcg_scu_disable, +}; + +struct clk_hw *__imx_clk_lpcg_scu(struct device *dev, const char *name, + const char *parent_name, unsigned long flags, + void __iomem *reg, u8 bit_idx, bool hw_gate) +{ + struct clk_lpcg_scu *clk; + struct clk_init_data init; + struct clk_hw *hw; + int ret; + + clk = kzalloc(sizeof(*clk), GFP_KERNEL); + if (!clk) + return ERR_PTR(-ENOMEM); + + clk->reg = reg; + clk->bit_idx = bit_idx; + clk->hw_gate = hw_gate; + + init.name = name; + init.ops = &clk_lpcg_scu_ops; + init.flags = CLK_SET_RATE_PARENT | flags; + init.parent_names = parent_name ? &parent_name : NULL; + init.num_parents = parent_name ? 1 : 0; + + clk->hw.init = &init; + + hw = &clk->hw; + ret = clk_hw_register(dev, hw); + if (ret) { + kfree(clk); + hw = ERR_PTR(ret); + return hw; + } + + if (dev) + dev_set_drvdata(dev, clk); + + return hw; +} + +void imx_clk_lpcg_scu_unregister(struct clk_hw *hw) +{ + struct clk_lpcg_scu *clk = to_clk_lpcg_scu(hw); + + clk_hw_unregister(&clk->hw); + kfree(clk); +} + +static int __maybe_unused imx_clk_lpcg_scu_suspend(struct device *dev) +{ + struct clk_lpcg_scu *clk = dev_get_drvdata(dev); + + clk->state = readl_relaxed(clk->reg); + dev_dbg(dev, "save lpcg state 0x%x\n", clk->state); + + return 0; +} + +static int __maybe_unused imx_clk_lpcg_scu_resume(struct device *dev) +{ + struct clk_lpcg_scu *clk = dev_get_drvdata(dev); + + /* + * FIXME: Sometimes writes don't work unless the CPU issues + * them twice + */ + + writel(clk->state, clk->reg); + writel(clk->state, clk->reg); + dev_dbg(dev, "restore lpcg state 0x%x\n", clk->state); + + return 0; +} + +const struct dev_pm_ops imx_clk_lpcg_scu_pm_ops = { + SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(imx_clk_lpcg_scu_suspend, + imx_clk_lpcg_scu_resume) +}; |