diff options
Diffstat (limited to 'drivers/clk/spear/clk-aux-synth.c')
| -rw-r--r-- | drivers/clk/spear/clk-aux-synth.c | 199 |
1 files changed, 199 insertions, 0 deletions
diff --git a/drivers/clk/spear/clk-aux-synth.c b/drivers/clk/spear/clk-aux-synth.c new file mode 100644 index 000000000..bdfb4421c --- /dev/null +++ b/drivers/clk/spear/clk-aux-synth.c @@ -0,0 +1,199 @@ +/* + * Copyright (C) 2012 ST Microelectronics + * Viresh Kumar <viresh.linux@gmail.com> + * + * This file is licensed under the terms of the GNU General Public + * License version 2. This program is licensed "as is" without any + * warranty of any kind, whether express or implied. + * + * Auxiliary Synthesizer clock implementation + */ + +#define pr_fmt(fmt) "clk-aux-synth: " fmt + +#include <linux/clk-provider.h> +#include <linux/slab.h> +#include <linux/io.h> +#include <linux/err.h> +#include "clk.h" + +/* + * DOC: Auxiliary Synthesizer clock + * + * Aux synth gives rate for different values of eq, x and y + * + * Fout from synthesizer can be given from two equations: + * Fout1 = (Fin * X/Y)/2 EQ1 + * Fout2 = Fin * X/Y EQ2 + */ + +#define to_clk_aux(_hw) container_of(_hw, struct clk_aux, hw) + +static struct aux_clk_masks default_aux_masks = { + .eq_sel_mask = AUX_EQ_SEL_MASK, + .eq_sel_shift = AUX_EQ_SEL_SHIFT, + .eq1_mask = AUX_EQ1_SEL, + .eq2_mask = AUX_EQ2_SEL, + .xscale_sel_mask = AUX_XSCALE_MASK, + .xscale_sel_shift = AUX_XSCALE_SHIFT, + .yscale_sel_mask = AUX_YSCALE_MASK, + .yscale_sel_shift = AUX_YSCALE_SHIFT, + .enable_bit = AUX_SYNT_ENB, +}; + +static unsigned long aux_calc_rate(struct clk_hw *hw, unsigned long prate, + int index) +{ + struct clk_aux *aux = to_clk_aux(hw); + struct aux_rate_tbl *rtbl = aux->rtbl; + u8 eq = rtbl[index].eq ? 1 : 2; + + return (((prate / 10000) * rtbl[index].xscale) / + (rtbl[index].yscale * eq)) * 10000; +} + +static long clk_aux_round_rate(struct clk_hw *hw, unsigned long drate, + unsigned long *prate) +{ + struct clk_aux *aux = to_clk_aux(hw); + int unused; + + return clk_round_rate_index(hw, drate, *prate, aux_calc_rate, + aux->rtbl_cnt, &unused); +} + +static unsigned long clk_aux_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct clk_aux *aux = to_clk_aux(hw); + unsigned int num = 1, den = 1, val, eqn; + unsigned long flags = 0; + + if (aux->lock) + spin_lock_irqsave(aux->lock, flags); + + val = readl_relaxed(aux->reg); + + if (aux->lock) + spin_unlock_irqrestore(aux->lock, flags); + + eqn = (val >> aux->masks->eq_sel_shift) & aux->masks->eq_sel_mask; + if (eqn == aux->masks->eq1_mask) + den = 2; + + /* calculate numerator */ + num = (val >> aux->masks->xscale_sel_shift) & + aux->masks->xscale_sel_mask; + + /* calculate denominator */ + den *= (val >> aux->masks->yscale_sel_shift) & + aux->masks->yscale_sel_mask; + + if (!den) + return 0; + + return (((parent_rate / 10000) * num) / den) * 10000; +} + +/* Configures new clock rate of aux */ +static int clk_aux_set_rate(struct clk_hw *hw, unsigned long drate, + unsigned long prate) +{ + struct clk_aux *aux = to_clk_aux(hw); + struct aux_rate_tbl *rtbl = aux->rtbl; + unsigned long val, flags = 0; + int i; + + clk_round_rate_index(hw, drate, prate, aux_calc_rate, aux->rtbl_cnt, + &i); + + if (aux->lock) + spin_lock_irqsave(aux->lock, flags); + + val = readl_relaxed(aux->reg) & + ~(aux->masks->eq_sel_mask << aux->masks->eq_sel_shift); + val |= (rtbl[i].eq & aux->masks->eq_sel_mask) << + aux->masks->eq_sel_shift; + val &= ~(aux->masks->xscale_sel_mask << aux->masks->xscale_sel_shift); + val |= (rtbl[i].xscale & aux->masks->xscale_sel_mask) << + aux->masks->xscale_sel_shift; + val &= ~(aux->masks->yscale_sel_mask << aux->masks->yscale_sel_shift); + val |= (rtbl[i].yscale & aux->masks->yscale_sel_mask) << + aux->masks->yscale_sel_shift; + writel_relaxed(val, aux->reg); + + if (aux->lock) + spin_unlock_irqrestore(aux->lock, flags); + + return 0; +} + +static struct clk_ops clk_aux_ops = { + .recalc_rate = clk_aux_recalc_rate, + .round_rate = clk_aux_round_rate, + .set_rate = clk_aux_set_rate, +}; + +struct clk *clk_register_aux(const char *aux_name, const char *gate_name, + const char *parent_name, unsigned long flags, void __iomem *reg, + struct aux_clk_masks *masks, struct aux_rate_tbl *rtbl, + u8 rtbl_cnt, spinlock_t *lock, struct clk **gate_clk) +{ + struct clk_aux *aux; + struct clk_init_data init; + struct clk *clk; + + if (!aux_name || !parent_name || !reg || !rtbl || !rtbl_cnt) { + pr_err("Invalid arguments passed"); + return ERR_PTR(-EINVAL); + } + + aux = kzalloc(sizeof(*aux), GFP_KERNEL); + if (!aux) { + pr_err("could not allocate aux clk\n"); + return ERR_PTR(-ENOMEM); + } + + /* struct clk_aux assignments */ + if (!masks) + aux->masks = &default_aux_masks; + else + aux->masks = masks; + + aux->reg = reg; + aux->rtbl = rtbl; + aux->rtbl_cnt = rtbl_cnt; + aux->lock = lock; + aux->hw.init = &init; + + init.name = aux_name; + init.ops = &clk_aux_ops; + init.flags = flags; + init.parent_names = &parent_name; + init.num_parents = 1; + + clk = clk_register(NULL, &aux->hw); + if (IS_ERR_OR_NULL(clk)) + goto free_aux; + + if (gate_name) { + struct clk *tgate_clk; + + tgate_clk = clk_register_gate(NULL, gate_name, aux_name, + CLK_SET_RATE_PARENT, reg, + aux->masks->enable_bit, 0, lock); + if (IS_ERR_OR_NULL(tgate_clk)) + goto free_aux; + + if (gate_clk) + *gate_clk = tgate_clk; + } + + return clk; + +free_aux: + kfree(aux); + pr_err("clk register failed\n"); + + return NULL; +} |