diff options
Diffstat (limited to 'drivers/clk/imx/clk-pllv4.c')
| -rw-r--r-- | drivers/clk/imx/clk-pllv4.c | 240 |
1 files changed, 240 insertions, 0 deletions
diff --git a/drivers/clk/imx/clk-pllv4.c b/drivers/clk/imx/clk-pllv4.c new file mode 100644 index 000000000..8ec703f27 --- /dev/null +++ b/drivers/clk/imx/clk-pllv4.c @@ -0,0 +1,240 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (C) 2016 Freescale Semiconductor, Inc. + * Copyright 2017~2018 NXP + * + * Author: 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/iopoll.h> +#include <linux/slab.h> + +#include "clk.h" + +/* PLL Control Status Register (xPLLCSR) */ +#define PLL_CSR_OFFSET 0x0 +#define PLL_VLD BIT(24) +#define PLL_EN BIT(0) + +/* PLL Configuration Register (xPLLCFG) */ +#define PLL_CFG_OFFSET 0x08 +#define BP_PLL_MULT 16 +#define BM_PLL_MULT (0x7f << 16) + +/* PLL Numerator Register (xPLLNUM) */ +#define PLL_NUM_OFFSET 0x10 + +/* PLL Denominator Register (xPLLDENOM) */ +#define PLL_DENOM_OFFSET 0x14 + +#define MAX_MFD 0x3fffffff +#define DEFAULT_MFD 1000000 + +struct clk_pllv4 { + struct clk_hw hw; + void __iomem *base; +}; + +/* Valid PLL MULT Table */ +static const int pllv4_mult_table[] = {33, 27, 22, 20, 17, 16}; + +#define to_clk_pllv4(__hw) container_of(__hw, struct clk_pllv4, hw) + +#define LOCK_TIMEOUT_US USEC_PER_MSEC + +static inline int clk_pllv4_wait_lock(struct clk_pllv4 *pll) +{ + u32 csr; + + return readl_poll_timeout(pll->base + PLL_CSR_OFFSET, + csr, csr & PLL_VLD, 0, LOCK_TIMEOUT_US); +} + +static int clk_pllv4_is_prepared(struct clk_hw *hw) +{ + struct clk_pllv4 *pll = to_clk_pllv4(hw); + + if (readl_relaxed(pll->base) & PLL_EN) + return 1; + + return 0; +} + +static unsigned long clk_pllv4_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct clk_pllv4 *pll = to_clk_pllv4(hw); + u32 mult, mfn, mfd; + u64 temp64; + + mult = readl_relaxed(pll->base + PLL_CFG_OFFSET); + mult &= BM_PLL_MULT; + mult >>= BP_PLL_MULT; + + mfn = readl_relaxed(pll->base + PLL_NUM_OFFSET); + mfd = readl_relaxed(pll->base + PLL_DENOM_OFFSET); + temp64 = parent_rate; + temp64 *= mfn; + do_div(temp64, mfd); + + return (parent_rate * mult) + (u32)temp64; +} + +static long clk_pllv4_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *prate) +{ + unsigned long parent_rate = *prate; + unsigned long round_rate, i; + u32 mfn, mfd = DEFAULT_MFD; + bool found = false; + u64 temp64; + + for (i = 0; i < ARRAY_SIZE(pllv4_mult_table); i++) { + round_rate = parent_rate * pllv4_mult_table[i]; + if (rate >= round_rate) { + found = true; + break; + } + } + + if (!found) { + pr_warn("%s: unable to round rate %lu, parent rate %lu\n", + clk_hw_get_name(hw), rate, parent_rate); + return 0; + } + + if (parent_rate <= MAX_MFD) + mfd = parent_rate; + + temp64 = (u64)(rate - round_rate); + temp64 *= mfd; + do_div(temp64, parent_rate); + mfn = temp64; + + /* + * NOTE: The value of numerator must always be configured to be + * less than the value of the denominator. If we can't get a proper + * pair of mfn/mfd, we simply return the round_rate without using + * the frac part. + */ + if (mfn >= mfd) + return round_rate; + + temp64 = (u64)parent_rate; + temp64 *= mfn; + do_div(temp64, mfd); + + return round_rate + (u32)temp64; +} + +static bool clk_pllv4_is_valid_mult(unsigned int mult) +{ + int i; + + /* check if mult is in valid MULT table */ + for (i = 0; i < ARRAY_SIZE(pllv4_mult_table); i++) { + if (pllv4_mult_table[i] == mult) + return true; + } + + return false; +} + +static int clk_pllv4_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct clk_pllv4 *pll = to_clk_pllv4(hw); + u32 val, mult, mfn, mfd = DEFAULT_MFD; + u64 temp64; + + mult = rate / parent_rate; + + if (!clk_pllv4_is_valid_mult(mult)) + return -EINVAL; + + if (parent_rate <= MAX_MFD) + mfd = parent_rate; + + temp64 = (u64)(rate - mult * parent_rate); + temp64 *= mfd; + do_div(temp64, parent_rate); + mfn = temp64; + + val = readl_relaxed(pll->base + PLL_CFG_OFFSET); + val &= ~BM_PLL_MULT; + val |= mult << BP_PLL_MULT; + writel_relaxed(val, pll->base + PLL_CFG_OFFSET); + + writel_relaxed(mfn, pll->base + PLL_NUM_OFFSET); + writel_relaxed(mfd, pll->base + PLL_DENOM_OFFSET); + + return 0; +} + +static int clk_pllv4_prepare(struct clk_hw *hw) +{ + u32 val; + struct clk_pllv4 *pll = to_clk_pllv4(hw); + + val = readl_relaxed(pll->base); + val |= PLL_EN; + writel_relaxed(val, pll->base); + + return clk_pllv4_wait_lock(pll); +} + +static void clk_pllv4_unprepare(struct clk_hw *hw) +{ + u32 val; + struct clk_pllv4 *pll = to_clk_pllv4(hw); + + val = readl_relaxed(pll->base); + val &= ~PLL_EN; + writel_relaxed(val, pll->base); +} + +static const struct clk_ops clk_pllv4_ops = { + .recalc_rate = clk_pllv4_recalc_rate, + .round_rate = clk_pllv4_round_rate, + .set_rate = clk_pllv4_set_rate, + .prepare = clk_pllv4_prepare, + .unprepare = clk_pllv4_unprepare, + .is_prepared = clk_pllv4_is_prepared, +}; + +struct clk_hw *imx_clk_hw_pllv4(const char *name, const char *parent_name, + void __iomem *base) +{ + struct clk_pllv4 *pll; + struct clk_hw *hw; + struct clk_init_data init; + int ret; + + pll = kzalloc(sizeof(*pll), GFP_KERNEL); + if (!pll) + return ERR_PTR(-ENOMEM); + + pll->base = base; + + init.name = name; + init.ops = &clk_pllv4_ops; + init.parent_names = &parent_name; + init.num_parents = 1; + init.flags = CLK_SET_RATE_GATE; + + pll->hw.init = &init; + + hw = &pll->hw; + ret = clk_hw_register(NULL, hw); + if (ret) { + kfree(pll); + hw = ERR_PTR(ret); + } + + return hw; +} |