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path: root/drivers/clk/imx/clk-lpcg-scu.c
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-rw-r--r--drivers/clk/imx/clk-lpcg-scu.c163
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)
+};