diff options
| -rw-r--r-- | drivers/clk/imx/clk-composite-8m.c | 170 |
1 files changed, 170 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 0000000..95120d6 --- /dev/null +++ b/drivers/clk/imx/clk-composite-8m.c @@ -0,0 +1,170 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright 2019 NXP + */ + +#include <common.h> +#include <asm/io.h> +#include <malloc.h> +#include <clk-uclass.h> +#include <dm/device.h> +#include <linux/clk-provider.h> +#include <clk.h> +#include "clk.h" + +#define UBOOT_DM_CLK_IMX_COMPOSITE "imx_clk_composite" + +#define PCG_PREDIV_SHIFT 16 +#define PCG_PREDIV_WIDTH 3 +#define PCG_PREDIV_MAX 8 + +#define PCG_DIV_SHIFT 0 +#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 *clk) +{ + struct clk_divider *divider = (struct clk_divider *)to_clk_divider(clk); + struct clk_composite *composite = (struct clk_composite *)clk->data; + ulong parent_rate = clk_get_parent_rate(&composite->clk); + unsigned long prediv_rate; + unsigned int prediv_value; + unsigned int div_value; + + debug("%s: name %s prate: %lu reg: %p\n", __func__, + (&composite->clk)->dev->name, parent_rate, divider->reg); + prediv_value = readl(divider->reg) >> divider->shift; + prediv_value &= clk_div_mask(divider->width); + + prediv_rate = divider_recalc_rate(clk, 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(clk, 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; +} + +/* + * The clk are bound to a dev, because it is part of composite clk + * use composite clk to get dev + */ +static ulong imx8m_clk_composite_divider_set_rate(struct clk *clk, + unsigned long rate) +{ + struct clk_divider *divider = (struct clk_divider *)to_clk_divider(clk); + struct clk_composite *composite = (struct clk_composite *)clk->data; + ulong parent_rate = clk_get_parent_rate(&composite->clk); + int prediv_value; + int div_value; + int ret; + u32 val; + + ret = imx8m_clk_composite_compute_dividers(rate, parent_rate, + &prediv_value, &div_value); + if (ret) + return ret; + + val = readl(divider->reg); + val &= ~((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; + writel(val, divider->reg); + + return clk_get_rate(&composite->clk); +} + +static const struct clk_ops imx8m_clk_composite_divider_ops = { + .get_rate = imx8m_clk_composite_divider_recalc_rate, + .set_rate = imx8m_clk_composite_divider_set_rate, +}; + +struct clk *imx8m_clk_composite_flags(const char *name, + const char * const *parent_names, + int num_parents, void __iomem *reg, + unsigned long flags) +{ + struct clk *clk = ERR_PTR(-ENOMEM); + struct clk_divider *div = NULL; + struct clk_gate *gate = NULL; + struct clk_mux *mux = NULL; + + mux = kzalloc(sizeof(*mux), GFP_KERNEL); + if (!mux) + goto fail; + + mux->reg = reg; + mux->shift = PCG_PCS_SHIFT; + mux->mask = PCG_PCS_MASK; + mux->num_parents = num_parents; + mux->flags = flags; + mux->parent_names = parent_names; + + div = kzalloc(sizeof(*div), GFP_KERNEL); + if (!div) + goto fail; + + div->reg = reg; + div->shift = PCG_PREDIV_SHIFT; + div->width = PCG_PREDIV_WIDTH; + div->flags = CLK_DIVIDER_ROUND_CLOSEST | flags; + + gate = kzalloc(sizeof(*gate), GFP_KERNEL); + if (!gate) + goto fail; + + gate->reg = reg; + gate->bit_idx = PCG_CGC_SHIFT; + gate->flags = flags; + + clk = clk_register_composite(NULL, name, + parent_names, num_parents, + &mux->clk, &clk_mux_ops, &div->clk, + &imx8m_clk_composite_divider_ops, + &gate->clk, &clk_gate_ops, flags); + if (IS_ERR(clk)) + goto fail; + + return clk; + +fail: + kfree(gate); + kfree(div); + kfree(mux); + return ERR_CAST(clk); +} |