diff options
Diffstat (limited to 'drivers/clk/imx/clk-composite-8m.c')
-rw-r--r-- | drivers/clk/imx/clk-composite-8m.c | 251 |
1 files changed, 251 insertions, 0 deletions
diff --git a/drivers/clk/imx/clk-composite-8m.c b/drivers/clk/imx/clk-composite-8m.c new file mode 100644 index 000000000..75e05582c --- /dev/null +++ b/drivers/clk/imx/clk-composite-8m.c @@ -0,0 +1,251 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright 2018 NXP + */ + +#include <linux/clk-provider.h> +#include <linux/errno.h> +#include <linux/export.h> +#include <linux/io.h> +#include <linux/slab.h> + +#include "clk.h" + +#define PCG_PREDIV_SHIFT 16 +#define PCG_PREDIV_WIDTH 3 +#define PCG_PREDIV_MAX 8 + +#define PCG_DIV_SHIFT 0 +#define PCG_CORE_DIV_WIDTH 3 +#define PCG_DIV_WIDTH 6 +#define PCG_DIV_MAX 64 + +#define PCG_PCS_SHIFT 24 +#define PCG_PCS_MASK 0x7 + +#define PCG_CGC_SHIFT 28 + +static unsigned long imx8m_clk_composite_divider_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct clk_divider *divider = to_clk_divider(hw); + unsigned long prediv_rate; + unsigned int prediv_value; + unsigned int div_value; + + prediv_value = readl(divider->reg) >> divider->shift; + prediv_value &= clk_div_mask(divider->width); + + prediv_rate = divider_recalc_rate(hw, parent_rate, prediv_value, + NULL, divider->flags, + divider->width); + + div_value = readl(divider->reg) >> PCG_DIV_SHIFT; + div_value &= clk_div_mask(PCG_DIV_WIDTH); + + return divider_recalc_rate(hw, prediv_rate, div_value, NULL, + divider->flags, PCG_DIV_WIDTH); +} + +static int imx8m_clk_composite_compute_dividers(unsigned long rate, + unsigned long parent_rate, + int *prediv, int *postdiv) +{ + int div1, div2; + int error = INT_MAX; + int ret = -EINVAL; + + *prediv = 1; + *postdiv = 1; + + for (div1 = 1; div1 <= PCG_PREDIV_MAX; div1++) { + for (div2 = 1; div2 <= PCG_DIV_MAX; div2++) { + int new_error = ((parent_rate / div1) / div2) - rate; + + if (abs(new_error) < abs(error)) { + *prediv = div1; + *postdiv = div2; + error = new_error; + ret = 0; + } + } + } + return ret; +} + +static long imx8m_clk_composite_divider_round_rate(struct clk_hw *hw, + unsigned long rate, + unsigned long *prate) +{ + int prediv_value; + int div_value; + + imx8m_clk_composite_compute_dividers(rate, *prate, + &prediv_value, &div_value); + rate = DIV_ROUND_UP(*prate, prediv_value); + + return DIV_ROUND_UP(rate, div_value); + +} + +static int imx8m_clk_composite_divider_set_rate(struct clk_hw *hw, + unsigned long rate, + unsigned long parent_rate) +{ + struct clk_divider *divider = to_clk_divider(hw); + unsigned long flags; + int prediv_value; + int div_value; + int ret; + u32 orig, val; + + ret = imx8m_clk_composite_compute_dividers(rate, parent_rate, + &prediv_value, &div_value); + if (ret) + return -EINVAL; + + spin_lock_irqsave(divider->lock, flags); + + orig = readl(divider->reg); + val = orig & ~((clk_div_mask(divider->width) << divider->shift) | + (clk_div_mask(PCG_DIV_WIDTH) << PCG_DIV_SHIFT)); + + val |= (u32)(prediv_value - 1) << divider->shift; + val |= (u32)(div_value - 1) << PCG_DIV_SHIFT; + + if (val != orig) + writel(val, divider->reg); + + spin_unlock_irqrestore(divider->lock, flags); + + return ret; +} + +static const struct clk_ops imx8m_clk_composite_divider_ops = { + .recalc_rate = imx8m_clk_composite_divider_recalc_rate, + .round_rate = imx8m_clk_composite_divider_round_rate, + .set_rate = imx8m_clk_composite_divider_set_rate, +}; + +static u8 imx8m_clk_composite_mux_get_parent(struct clk_hw *hw) +{ + return clk_mux_ops.get_parent(hw); +} + +static int imx8m_clk_composite_mux_set_parent(struct clk_hw *hw, u8 index) +{ + struct clk_mux *mux = to_clk_mux(hw); + u32 val = clk_mux_index_to_val(mux->table, mux->flags, index); + unsigned long flags = 0; + u32 reg; + + if (mux->lock) + spin_lock_irqsave(mux->lock, flags); + + reg = readl(mux->reg); + reg &= ~(mux->mask << mux->shift); + val = val << mux->shift; + reg |= val; + /* + * write twice to make sure non-target interface + * SEL_A/B point the same clk input. + */ + writel(reg, mux->reg); + writel(reg, mux->reg); + + if (mux->lock) + spin_unlock_irqrestore(mux->lock, flags); + + return 0; +} + +static int +imx8m_clk_composite_mux_determine_rate(struct clk_hw *hw, + struct clk_rate_request *req) +{ + return clk_mux_ops.determine_rate(hw, req); +} + + +static const struct clk_ops imx8m_clk_composite_mux_ops = { + .get_parent = imx8m_clk_composite_mux_get_parent, + .set_parent = imx8m_clk_composite_mux_set_parent, + .determine_rate = imx8m_clk_composite_mux_determine_rate, +}; + +struct clk_hw *imx8m_clk_hw_composite_flags(const char *name, + const char * const *parent_names, + int num_parents, void __iomem *reg, + u32 composite_flags, + unsigned long flags) +{ + struct clk_hw *hw = ERR_PTR(-ENOMEM), *mux_hw; + struct clk_hw *div_hw, *gate_hw; + struct clk_divider *div = NULL; + struct clk_gate *gate = NULL; + struct clk_mux *mux = NULL; + const struct clk_ops *divider_ops; + const struct clk_ops *mux_ops; + + mux = kzalloc(sizeof(*mux), GFP_KERNEL); + if (!mux) + goto fail; + + mux_hw = &mux->hw; + mux->reg = reg; + mux->shift = PCG_PCS_SHIFT; + mux->mask = PCG_PCS_MASK; + mux->lock = &imx_ccm_lock; + + div = kzalloc(sizeof(*div), GFP_KERNEL); + if (!div) + goto fail; + + div_hw = &div->hw; + div->reg = reg; + if (composite_flags & IMX_COMPOSITE_CORE) { + div->shift = PCG_DIV_SHIFT; + div->width = PCG_CORE_DIV_WIDTH; + divider_ops = &clk_divider_ops; + mux_ops = &imx8m_clk_composite_mux_ops; + } else if (composite_flags & IMX_COMPOSITE_BUS) { + div->shift = PCG_PREDIV_SHIFT; + div->width = PCG_PREDIV_WIDTH; + divider_ops = &imx8m_clk_composite_divider_ops; + mux_ops = &imx8m_clk_composite_mux_ops; + } else { + div->shift = PCG_PREDIV_SHIFT; + div->width = PCG_PREDIV_WIDTH; + divider_ops = &imx8m_clk_composite_divider_ops; + mux_ops = &clk_mux_ops; + if (!(composite_flags & IMX_COMPOSITE_FW_MANAGED)) + flags |= CLK_SET_PARENT_GATE; + } + + div->lock = &imx_ccm_lock; + div->flags = CLK_DIVIDER_ROUND_CLOSEST; + + gate = kzalloc(sizeof(*gate), GFP_KERNEL); + if (!gate) + goto fail; + + gate_hw = &gate->hw; + gate->reg = reg; + gate->bit_idx = PCG_CGC_SHIFT; + gate->lock = &imx_ccm_lock; + + hw = clk_hw_register_composite(NULL, name, parent_names, num_parents, + mux_hw, mux_ops, div_hw, + divider_ops, gate_hw, &clk_gate_ops, flags); + if (IS_ERR(hw)) + goto fail; + + return hw; + +fail: + kfree(gate); + kfree(div); + kfree(mux); + return ERR_CAST(hw); +} +EXPORT_SYMBOL_GPL(imx8m_clk_hw_composite_flags); |