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Diffstat (limited to '')
-rw-r--r-- | drivers/clk/zynqmp/pll.c | 347 |
1 files changed, 347 insertions, 0 deletions
diff --git a/drivers/clk/zynqmp/pll.c b/drivers/clk/zynqmp/pll.c new file mode 100644 index 000000000..0d3e1377b --- /dev/null +++ b/drivers/clk/zynqmp/pll.c @@ -0,0 +1,347 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Zynq UltraScale+ MPSoC PLL driver + * + * Copyright (C) 2016-2018 Xilinx + */ + +#include <linux/clk.h> +#include <linux/clk-provider.h> +#include <linux/slab.h> +#include "clk-zynqmp.h" + +/** + * struct zynqmp_pll - PLL clock + * @hw: Handle between common and hardware-specific interfaces + * @clk_id: PLL clock ID + * @set_pll_mode: Whether an IOCTL_SET_PLL_FRAC_MODE request be sent to ATF + */ +struct zynqmp_pll { + struct clk_hw hw; + u32 clk_id; + bool set_pll_mode; +}; + +#define to_zynqmp_pll(_hw) container_of(_hw, struct zynqmp_pll, hw) + +#define PLL_FBDIV_MIN 25 +#define PLL_FBDIV_MAX 125 + +#define PS_PLL_VCO_MIN 1500000000 +#define PS_PLL_VCO_MAX 3000000000UL + +enum pll_mode { + PLL_MODE_INT = 0, + PLL_MODE_FRAC = 1, + PLL_MODE_ERROR = 2, +}; + +#define FRAC_OFFSET 0x8 +#define PLLFCFG_FRAC_EN BIT(31) +#define FRAC_DIV BIT(16) /* 2^16 */ + +/** + * zynqmp_pll_get_mode() - Get mode of PLL + * @hw: Handle between common and hardware-specific interfaces + * + * Return: Mode of PLL + */ +static inline enum pll_mode zynqmp_pll_get_mode(struct clk_hw *hw) +{ + struct zynqmp_pll *clk = to_zynqmp_pll(hw); + u32 clk_id = clk->clk_id; + const char *clk_name = clk_hw_get_name(hw); + u32 ret_payload[PAYLOAD_ARG_CNT]; + int ret; + + ret = zynqmp_pm_get_pll_frac_mode(clk_id, ret_payload); + if (ret) { + pr_debug("%s() PLL get frac mode failed for %s, ret = %d\n", + __func__, clk_name, ret); + return PLL_MODE_ERROR; + } + + return ret_payload[1]; +} + +/** + * zynqmp_pll_set_mode() - Set the PLL mode + * @hw: Handle between common and hardware-specific interfaces + * @on: Flag to determine the mode + */ +static inline void zynqmp_pll_set_mode(struct clk_hw *hw, bool on) +{ + struct zynqmp_pll *clk = to_zynqmp_pll(hw); + u32 clk_id = clk->clk_id; + const char *clk_name = clk_hw_get_name(hw); + int ret; + u32 mode; + + if (on) + mode = PLL_MODE_FRAC; + else + mode = PLL_MODE_INT; + + ret = zynqmp_pm_set_pll_frac_mode(clk_id, mode); + if (ret) + pr_debug("%s() PLL set frac mode failed for %s, ret = %d\n", + __func__, clk_name, ret); + else + clk->set_pll_mode = true; +} + +/** + * zynqmp_pll_round_rate() - Round a clock frequency + * @hw: Handle between common and hardware-specific interfaces + * @rate: Desired clock frequency + * @prate: Clock frequency of parent clock + * + * Return: Frequency closest to @rate the hardware can generate + */ +static long zynqmp_pll_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *prate) +{ + u32 fbdiv; + u32 mult, div; + + /* Let rate fall inside the range PS_PLL_VCO_MIN ~ PS_PLL_VCO_MAX */ + if (rate > PS_PLL_VCO_MAX) { + div = DIV_ROUND_UP(rate, PS_PLL_VCO_MAX); + rate = rate / div; + } + if (rate < PS_PLL_VCO_MIN) { + mult = DIV_ROUND_UP(PS_PLL_VCO_MIN, rate); + rate = rate * mult; + } + + fbdiv = DIV_ROUND_CLOSEST(rate, *prate); + if (fbdiv < PLL_FBDIV_MIN || fbdiv > PLL_FBDIV_MAX) { + fbdiv = clamp_t(u32, fbdiv, PLL_FBDIV_MIN, PLL_FBDIV_MAX); + rate = *prate * fbdiv; + } + + return rate; +} + +/** + * zynqmp_pll_recalc_rate() - Recalculate clock frequency + * @hw: Handle between common and hardware-specific interfaces + * @parent_rate: Clock frequency of parent clock + * + * Return: Current clock frequency or 0 in case of error + */ +static unsigned long zynqmp_pll_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct zynqmp_pll *clk = to_zynqmp_pll(hw); + u32 clk_id = clk->clk_id; + const char *clk_name = clk_hw_get_name(hw); + u32 fbdiv, data; + unsigned long rate, frac; + u32 ret_payload[PAYLOAD_ARG_CNT]; + int ret; + enum pll_mode mode; + + ret = zynqmp_pm_clock_getdivider(clk_id, &fbdiv); + if (ret) { + pr_debug("%s() get divider failed for %s, ret = %d\n", + __func__, clk_name, ret); + return 0ul; + } + + mode = zynqmp_pll_get_mode(hw); + if (mode == PLL_MODE_ERROR) + return 0ul; + + rate = parent_rate * fbdiv; + if (mode == PLL_MODE_FRAC) { + zynqmp_pm_get_pll_frac_data(clk_id, ret_payload); + data = ret_payload[1]; + frac = (parent_rate * data) / FRAC_DIV; + rate = rate + frac; + } + + return rate; +} + +/** + * zynqmp_pll_set_rate() - Set rate of PLL + * @hw: Handle between common and hardware-specific interfaces + * @rate: Frequency of clock to be set + * @parent_rate: Clock frequency of parent clock + * + * Set PLL divider to set desired rate. + * + * Returns: rate which is set on success else error code + */ +static int zynqmp_pll_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct zynqmp_pll *clk = to_zynqmp_pll(hw); + u32 clk_id = clk->clk_id; + const char *clk_name = clk_hw_get_name(hw); + u32 fbdiv; + long rate_div, frac, m, f; + int ret; + + rate_div = (rate * FRAC_DIV) / parent_rate; + f = rate_div % FRAC_DIV; + zynqmp_pll_set_mode(hw, !!f); + + if (f) { + m = rate_div / FRAC_DIV; + m = clamp_t(u32, m, (PLL_FBDIV_MIN), (PLL_FBDIV_MAX)); + rate = parent_rate * m; + frac = (parent_rate * f) / FRAC_DIV; + + ret = zynqmp_pm_clock_setdivider(clk_id, m); + if (ret == -EUSERS) + WARN(1, "More than allowed devices are using the %s, which is forbidden\n", + clk_name); + else if (ret) + pr_debug("%s() set divider failed for %s, ret = %d\n", + __func__, clk_name, ret); + zynqmp_pm_set_pll_frac_data(clk_id, f); + + return rate + frac; + } + + fbdiv = DIV_ROUND_CLOSEST(rate, parent_rate); + fbdiv = clamp_t(u32, fbdiv, PLL_FBDIV_MIN, PLL_FBDIV_MAX); + ret = zynqmp_pm_clock_setdivider(clk_id, fbdiv); + if (ret) + pr_debug("%s() set divider failed for %s, ret = %d\n", + __func__, clk_name, ret); + + return parent_rate * fbdiv; +} + +/** + * zynqmp_pll_is_enabled() - Check if a clock is enabled + * @hw: Handle between common and hardware-specific interfaces + * + * Return: 1 if the clock is enabled, 0 otherwise + */ +static int zynqmp_pll_is_enabled(struct clk_hw *hw) +{ + struct zynqmp_pll *clk = to_zynqmp_pll(hw); + const char *clk_name = clk_hw_get_name(hw); + u32 clk_id = clk->clk_id; + unsigned int state; + int ret; + + ret = zynqmp_pm_clock_getstate(clk_id, &state); + if (ret) { + pr_debug("%s() clock get state failed for %s, ret = %d\n", + __func__, clk_name, ret); + return -EIO; + } + + return state ? 1 : 0; +} + +/** + * zynqmp_pll_enable() - Enable clock + * @hw: Handle between common and hardware-specific interfaces + * + * Return: 0 on success else error code + */ +static int zynqmp_pll_enable(struct clk_hw *hw) +{ + struct zynqmp_pll *clk = to_zynqmp_pll(hw); + const char *clk_name = clk_hw_get_name(hw); + u32 clk_id = clk->clk_id; + int ret; + + /* + * Don't skip enabling clock if there is an IOCTL_SET_PLL_FRAC_MODE request + * that has been sent to ATF. + */ + if (zynqmp_pll_is_enabled(hw) && (!clk->set_pll_mode)) + return 0; + + clk->set_pll_mode = false; + + ret = zynqmp_pm_clock_enable(clk_id); + if (ret) + pr_debug("%s() clock enable failed for %s, ret = %d\n", + __func__, clk_name, ret); + + return ret; +} + +/** + * zynqmp_pll_disable() - Disable clock + * @hw: Handle between common and hardware-specific interfaces + */ +static void zynqmp_pll_disable(struct clk_hw *hw) +{ + struct zynqmp_pll *clk = to_zynqmp_pll(hw); + const char *clk_name = clk_hw_get_name(hw); + u32 clk_id = clk->clk_id; + int ret; + + if (!zynqmp_pll_is_enabled(hw)) + return; + + ret = zynqmp_pm_clock_disable(clk_id); + if (ret) + pr_debug("%s() clock disable failed for %s, ret = %d\n", + __func__, clk_name, ret); +} + +static const struct clk_ops zynqmp_pll_ops = { + .enable = zynqmp_pll_enable, + .disable = zynqmp_pll_disable, + .is_enabled = zynqmp_pll_is_enabled, + .round_rate = zynqmp_pll_round_rate, + .recalc_rate = zynqmp_pll_recalc_rate, + .set_rate = zynqmp_pll_set_rate, +}; + +/** + * zynqmp_clk_register_pll() - Register PLL with the clock framework + * @name: PLL name + * @clk_id: Clock ID + * @parents: Name of this clock's parents + * @num_parents: Number of parents + * @nodes: Clock topology node + * + * Return: clock hardware to the registered clock + */ +struct clk_hw *zynqmp_clk_register_pll(const char *name, u32 clk_id, + const char * const *parents, + u8 num_parents, + const struct clock_topology *nodes) +{ + struct zynqmp_pll *pll; + struct clk_hw *hw; + struct clk_init_data init; + int ret; + + init.name = name; + init.ops = &zynqmp_pll_ops; + + init.flags = zynqmp_clk_map_common_ccf_flags(nodes->flag); + + init.parent_names = parents; + init.num_parents = 1; + + pll = kzalloc(sizeof(*pll), GFP_KERNEL); + if (!pll) + return ERR_PTR(-ENOMEM); + + pll->hw.init = &init; + pll->clk_id = clk_id; + + hw = &pll->hw; + ret = clk_hw_register(NULL, hw); + if (ret) { + kfree(pll); + return ERR_PTR(ret); + } + + clk_hw_set_rate_range(hw, PS_PLL_VCO_MIN, PS_PLL_VCO_MAX); + + return hw; +} |