diff options
Diffstat (limited to 'drivers/clk/imx/clk-pllv1.c')
-rw-r--r-- | drivers/clk/imx/clk-pllv1.c | 145 |
1 files changed, 145 insertions, 0 deletions
diff --git a/drivers/clk/imx/clk-pllv1.c b/drivers/clk/imx/clk-pllv1.c new file mode 100644 index 000000000..93ee81b28 --- /dev/null +++ b/drivers/clk/imx/clk-pllv1.c @@ -0,0 +1,145 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/bits.h> +#include <linux/clk-provider.h> +#include <linux/io.h> +#include <linux/slab.h> +#include <linux/kernel.h> +#include <linux/err.h> + +#include "clk.h" + +#define MFN_BITS (10) +#define MFN_SIGN (BIT(MFN_BITS - 1)) +#define MFN_MASK (MFN_SIGN - 1) + +/** + * struct clk_pllv1 - IMX PLLv1 clock descriptor + * + * @hw: clock source + * @base: base address of pll registers + * @type: type of IMX_PLLV1 + * + * PLL clock version 1, found on i.MX1/21/25/27/31/35 + */ +struct clk_pllv1 { + struct clk_hw hw; + void __iomem *base; + enum imx_pllv1_type type; +}; + +#define to_clk_pllv1(clk) (container_of(clk, struct clk_pllv1, clk)) + +static inline bool is_imx1_pllv1(struct clk_pllv1 *pll) +{ + return pll->type == IMX_PLLV1_IMX1; +} + +static inline bool is_imx21_pllv1(struct clk_pllv1 *pll) +{ + return pll->type == IMX_PLLV1_IMX21; +} + +static inline bool is_imx27_pllv1(struct clk_pllv1 *pll) +{ + return pll->type == IMX_PLLV1_IMX27; +} + +static inline bool mfn_is_negative(struct clk_pllv1 *pll, unsigned int mfn) +{ + return !is_imx1_pllv1(pll) && !is_imx21_pllv1(pll) && (mfn & MFN_SIGN); +} + +static unsigned long clk_pllv1_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct clk_pllv1 *pll = to_clk_pllv1(hw); + unsigned long long ull; + int mfn_abs; + unsigned int mfi, mfn, mfd, pd; + u32 reg; + unsigned long rate; + + reg = readl(pll->base); + + /* + * Get the resulting clock rate from a PLL register value and the input + * frequency. PLLs with this register layout can be found on i.MX1, + * i.MX21, i.MX27 and i,MX31 + * + * mfi + mfn / (mfd + 1) + * f = 2 * f_ref * -------------------- + * pd + 1 + */ + + mfi = (reg >> 10) & 0xf; + mfn = reg & 0x3ff; + mfd = (reg >> 16) & 0x3ff; + pd = (reg >> 26) & 0xf; + + mfi = mfi <= 5 ? 5 : mfi; + + mfn_abs = mfn; + + /* + * On all i.MXs except i.MX1 and i.MX21 mfn is a 10bit + * 2's complements number. + * On i.MX27 the bit 9 is the sign bit. + */ + if (mfn_is_negative(pll, mfn)) { + if (is_imx27_pllv1(pll)) + mfn_abs = mfn & MFN_MASK; + else + mfn_abs = BIT(MFN_BITS) - mfn; + } + + rate = parent_rate * 2; + rate /= pd + 1; + + ull = (unsigned long long)rate * mfn_abs; + + do_div(ull, mfd + 1); + + if (mfn_is_negative(pll, mfn)) + ull = (rate * mfi) - ull; + else + ull = (rate * mfi) + ull; + + return ull; +} + +static const struct clk_ops clk_pllv1_ops = { + .recalc_rate = clk_pllv1_recalc_rate, +}; + +struct clk_hw *imx_clk_hw_pllv1(enum imx_pllv1_type type, const char *name, + const char *parent, void __iomem *base) +{ + struct clk_pllv1 *pll; + struct clk_hw *hw; + struct clk_init_data init; + int ret; + + pll = kmalloc(sizeof(*pll), GFP_KERNEL); + if (!pll) + return ERR_PTR(-ENOMEM); + + pll->base = base; + pll->type = type; + + init.name = name; + init.ops = &clk_pllv1_ops; + init.flags = 0; + init.parent_names = &parent; + init.num_parents = 1; + + pll->hw.init = &init; + hw = &pll->hw; + + ret = clk_hw_register(NULL, hw); + if (ret) { + kfree(pll); + return ERR_PTR(ret); + } + + return hw; +} |