diff options
Diffstat (limited to 'drivers/clk/microchip/clk-core.c')
| -rw-r--r-- | drivers/clk/microchip/clk-core.c | 1031 |
1 files changed, 1031 insertions, 0 deletions
diff --git a/drivers/clk/microchip/clk-core.c b/drivers/clk/microchip/clk-core.c new file mode 100644 index 000000000..c3b301463 --- /dev/null +++ b/drivers/clk/microchip/clk-core.c @@ -0,0 +1,1031 @@ +/* + * Purna Chandra Mandal,<purna.mandal@microchip.com> + * Copyright (C) 2015 Microchip Technology Inc. All rights reserved. + * + * This program is free software; you can distribute it and/or modify it + * under the terms of the GNU General Public License (Version 2) as + * published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * for more details. + */ +#include <linux/clk-provider.h> +#include <linux/delay.h> +#include <linux/device.h> +#include <linux/interrupt.h> +#include <linux/iopoll.h> +#include <asm/mach-pic32/pic32.h> +#include <asm/traps.h> + +#include "clk-core.h" + +/* OSCCON Reg fields */ +#define OSC_CUR_MASK 0x07 +#define OSC_CUR_SHIFT 12 +#define OSC_NEW_MASK 0x07 +#define OSC_NEW_SHIFT 8 +#define OSC_SWEN BIT(0) + +/* SPLLCON Reg fields */ +#define PLL_RANGE_MASK 0x07 +#define PLL_RANGE_SHIFT 0 +#define PLL_ICLK_MASK 0x01 +#define PLL_ICLK_SHIFT 7 +#define PLL_IDIV_MASK 0x07 +#define PLL_IDIV_SHIFT 8 +#define PLL_ODIV_MASK 0x07 +#define PLL_ODIV_SHIFT 24 +#define PLL_MULT_MASK 0x7F +#define PLL_MULT_SHIFT 16 +#define PLL_MULT_MAX 128 +#define PLL_ODIV_MIN 1 +#define PLL_ODIV_MAX 5 + +/* Peripheral Bus Clock Reg Fields */ +#define PB_DIV_MASK 0x7f +#define PB_DIV_SHIFT 0 +#define PB_DIV_READY BIT(11) +#define PB_DIV_ENABLE BIT(15) +#define PB_DIV_MAX 128 +#define PB_DIV_MIN 0 + +/* Reference Oscillator Control Reg fields */ +#define REFO_SEL_MASK 0x0f +#define REFO_SEL_SHIFT 0 +#define REFO_ACTIVE BIT(8) +#define REFO_DIVSW_EN BIT(9) +#define REFO_OE BIT(12) +#define REFO_ON BIT(15) +#define REFO_DIV_SHIFT 16 +#define REFO_DIV_MASK 0x7fff + +/* Reference Oscillator Trim Register Fields */ +#define REFO_TRIM_REG 0x10 +#define REFO_TRIM_MASK 0x1ff +#define REFO_TRIM_SHIFT 23 +#define REFO_TRIM_MAX 511 + +/* Mux Slew Control Register fields */ +#define SLEW_BUSY BIT(0) +#define SLEW_DOWNEN BIT(1) +#define SLEW_UPEN BIT(2) +#define SLEW_DIV 0x07 +#define SLEW_DIV_SHIFT 8 +#define SLEW_SYSDIV 0x0f +#define SLEW_SYSDIV_SHIFT 20 + +/* Clock Poll Timeout */ +#define LOCK_TIMEOUT_US USEC_PER_MSEC + +/* SoC specific clock needed during SPLL clock rate switch */ +static struct clk_hw *pic32_sclk_hw; + +/* add instruction pipeline delay while CPU clock is in-transition. */ +#define cpu_nop5() \ +do { \ + __asm__ __volatile__("nop"); \ + __asm__ __volatile__("nop"); \ + __asm__ __volatile__("nop"); \ + __asm__ __volatile__("nop"); \ + __asm__ __volatile__("nop"); \ +} while (0) + +/* Perpheral bus clocks */ +struct pic32_periph_clk { + struct clk_hw hw; + void __iomem *ctrl_reg; + struct pic32_clk_common *core; +}; + +#define clkhw_to_pbclk(_hw) container_of(_hw, struct pic32_periph_clk, hw) + +static int pbclk_is_enabled(struct clk_hw *hw) +{ + struct pic32_periph_clk *pb = clkhw_to_pbclk(hw); + + return readl(pb->ctrl_reg) & PB_DIV_ENABLE; +} + +static int pbclk_enable(struct clk_hw *hw) +{ + struct pic32_periph_clk *pb = clkhw_to_pbclk(hw); + + writel(PB_DIV_ENABLE, PIC32_SET(pb->ctrl_reg)); + return 0; +} + +static void pbclk_disable(struct clk_hw *hw) +{ + struct pic32_periph_clk *pb = clkhw_to_pbclk(hw); + + writel(PB_DIV_ENABLE, PIC32_CLR(pb->ctrl_reg)); +} + +static unsigned long calc_best_divided_rate(unsigned long rate, + unsigned long parent_rate, + u32 divider_max, + u32 divider_min) +{ + unsigned long divided_rate, divided_rate_down, best_rate; + unsigned long div, div_up; + + /* eq. clk_rate = parent_rate / divider. + * + * Find best divider to produce closest of target divided rate. + */ + div = parent_rate / rate; + div = clamp_val(div, divider_min, divider_max); + div_up = clamp_val(div + 1, divider_min, divider_max); + + divided_rate = parent_rate / div; + divided_rate_down = parent_rate / div_up; + if (abs(rate - divided_rate_down) < abs(rate - divided_rate)) + best_rate = divided_rate_down; + else + best_rate = divided_rate; + + return best_rate; +} + +static inline u32 pbclk_read_pbdiv(struct pic32_periph_clk *pb) +{ + return ((readl(pb->ctrl_reg) >> PB_DIV_SHIFT) & PB_DIV_MASK) + 1; +} + +static unsigned long pbclk_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct pic32_periph_clk *pb = clkhw_to_pbclk(hw); + + return parent_rate / pbclk_read_pbdiv(pb); +} + +static long pbclk_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *parent_rate) +{ + return calc_best_divided_rate(rate, *parent_rate, + PB_DIV_MAX, PB_DIV_MIN); +} + +static int pbclk_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct pic32_periph_clk *pb = clkhw_to_pbclk(hw); + unsigned long flags; + u32 v, div; + int err; + + /* check & wait for DIV_READY */ + err = readl_poll_timeout(pb->ctrl_reg, v, v & PB_DIV_READY, + 1, LOCK_TIMEOUT_US); + if (err) + return err; + + /* calculate clkdiv and best rate */ + div = DIV_ROUND_CLOSEST(parent_rate, rate); + + spin_lock_irqsave(&pb->core->reg_lock, flags); + + /* apply new div */ + v = readl(pb->ctrl_reg); + v &= ~PB_DIV_MASK; + v |= (div - 1); + + pic32_syskey_unlock(); + + writel(v, pb->ctrl_reg); + + spin_unlock_irqrestore(&pb->core->reg_lock, flags); + + /* wait again for DIV_READY */ + err = readl_poll_timeout(pb->ctrl_reg, v, v & PB_DIV_READY, + 1, LOCK_TIMEOUT_US); + if (err) + return err; + + /* confirm that new div is applied correctly */ + return (pbclk_read_pbdiv(pb) == div) ? 0 : -EBUSY; +} + +const struct clk_ops pic32_pbclk_ops = { + .enable = pbclk_enable, + .disable = pbclk_disable, + .is_enabled = pbclk_is_enabled, + .recalc_rate = pbclk_recalc_rate, + .round_rate = pbclk_round_rate, + .set_rate = pbclk_set_rate, +}; + +struct clk *pic32_periph_clk_register(const struct pic32_periph_clk_data *desc, + struct pic32_clk_common *core) +{ + struct pic32_periph_clk *pbclk; + struct clk *clk; + + pbclk = devm_kzalloc(core->dev, sizeof(*pbclk), GFP_KERNEL); + if (!pbclk) + return ERR_PTR(-ENOMEM); + + pbclk->hw.init = &desc->init_data; + pbclk->core = core; + pbclk->ctrl_reg = desc->ctrl_reg + core->iobase; + + clk = devm_clk_register(core->dev, &pbclk->hw); + if (IS_ERR(clk)) { + dev_err(core->dev, "%s: clk_register() failed\n", __func__); + devm_kfree(core->dev, pbclk); + } + + return clk; +} + +/* Reference oscillator operations */ +struct pic32_ref_osc { + struct clk_hw hw; + void __iomem *ctrl_reg; + const u32 *parent_map; + struct pic32_clk_common *core; +}; + +#define clkhw_to_refosc(_hw) container_of(_hw, struct pic32_ref_osc, hw) + +static int roclk_is_enabled(struct clk_hw *hw) +{ + struct pic32_ref_osc *refo = clkhw_to_refosc(hw); + + return readl(refo->ctrl_reg) & REFO_ON; +} + +static int roclk_enable(struct clk_hw *hw) +{ + struct pic32_ref_osc *refo = clkhw_to_refosc(hw); + + writel(REFO_ON | REFO_OE, PIC32_SET(refo->ctrl_reg)); + return 0; +} + +static void roclk_disable(struct clk_hw *hw) +{ + struct pic32_ref_osc *refo = clkhw_to_refosc(hw); + + writel(REFO_ON | REFO_OE, PIC32_CLR(refo->ctrl_reg)); +} + +static void roclk_init(struct clk_hw *hw) +{ + /* initialize clock in disabled state */ + roclk_disable(hw); +} + +static u8 roclk_get_parent(struct clk_hw *hw) +{ + struct pic32_ref_osc *refo = clkhw_to_refosc(hw); + u32 v, i; + + v = (readl(refo->ctrl_reg) >> REFO_SEL_SHIFT) & REFO_SEL_MASK; + + if (!refo->parent_map) + return v; + + for (i = 0; i < clk_hw_get_num_parents(hw); i++) + if (refo->parent_map[i] == v) + return i; + + return -EINVAL; +} + +static unsigned long roclk_calc_rate(unsigned long parent_rate, + u32 rodiv, u32 rotrim) +{ + u64 rate64; + + /* fout = fin / [2 * {div + (trim / 512)}] + * = fin * 512 / [1024 * div + 2 * trim] + * = fin * 256 / (512 * div + trim) + * = (fin << 8) / ((div << 9) + trim) + */ + if (rotrim) { + rodiv = (rodiv << 9) + rotrim; + rate64 = parent_rate; + rate64 <<= 8; + do_div(rate64, rodiv); + } else if (rodiv) { + rate64 = parent_rate / (rodiv << 1); + } else { + rate64 = parent_rate; + } + return rate64; +} + +static void roclk_calc_div_trim(unsigned long rate, + unsigned long parent_rate, + u32 *rodiv_p, u32 *rotrim_p) +{ + u32 div, rotrim, rodiv; + u64 frac; + + /* Find integer approximation of floating-point arithmetic. + * fout = fin / [2 * {rodiv + (rotrim / 512)}] ... (1) + * i.e. fout = fin / 2 * DIV + * whereas DIV = rodiv + (rotrim / 512) + * + * Since kernel does not perform floating-point arithmatic so + * (rotrim/512) will be zero. And DIV & rodiv will result same. + * + * ie. fout = (fin * 256) / [(512 * rodiv) + rotrim] ... from (1) + * ie. rotrim = ((fin * 256) / fout) - (512 * DIV) + */ + if (parent_rate <= rate) { + div = 0; + frac = 0; + rodiv = 0; + rotrim = 0; + } else { + div = parent_rate / (rate << 1); + frac = parent_rate; + frac <<= 8; + do_div(frac, rate); + frac -= (u64)(div << 9); + + rodiv = (div > REFO_DIV_MASK) ? REFO_DIV_MASK : div; + rotrim = (frac >= REFO_TRIM_MAX) ? REFO_TRIM_MAX : frac; + } + + if (rodiv_p) + *rodiv_p = rodiv; + + if (rotrim_p) + *rotrim_p = rotrim; +} + +static unsigned long roclk_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct pic32_ref_osc *refo = clkhw_to_refosc(hw); + u32 v, rodiv, rotrim; + + /* get rodiv */ + v = readl(refo->ctrl_reg); + rodiv = (v >> REFO_DIV_SHIFT) & REFO_DIV_MASK; + + /* get trim */ + v = readl(refo->ctrl_reg + REFO_TRIM_REG); + rotrim = (v >> REFO_TRIM_SHIFT) & REFO_TRIM_MASK; + + return roclk_calc_rate(parent_rate, rodiv, rotrim); +} + +static long roclk_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *parent_rate) +{ + u32 rotrim, rodiv; + + /* calculate dividers for new rate */ + roclk_calc_div_trim(rate, *parent_rate, &rodiv, &rotrim); + + /* caclulate new rate (rounding) based on new rodiv & rotrim */ + return roclk_calc_rate(*parent_rate, rodiv, rotrim); +} + +static int roclk_determine_rate(struct clk_hw *hw, + struct clk_rate_request *req) +{ + struct clk_hw *parent_clk, *best_parent_clk = NULL; + unsigned int i, delta, best_delta = -1; + unsigned long parent_rate, best_parent_rate = 0; + unsigned long best = 0, nearest_rate; + + /* find a parent which can generate nearest clkrate >= rate */ + for (i = 0; i < clk_hw_get_num_parents(hw); i++) { + /* get parent */ + parent_clk = clk_hw_get_parent_by_index(hw, i); + if (!parent_clk) + continue; + + /* skip if parent runs slower than target rate */ + parent_rate = clk_hw_get_rate(parent_clk); + if (req->rate > parent_rate) + continue; + + nearest_rate = roclk_round_rate(hw, req->rate, &parent_rate); + delta = abs(nearest_rate - req->rate); + if ((nearest_rate >= req->rate) && (delta < best_delta)) { + best_parent_clk = parent_clk; + best_parent_rate = parent_rate; + best = nearest_rate; + best_delta = delta; + + if (delta == 0) + break; + } + } + + /* if no match found, retain old rate */ + if (!best_parent_clk) { + pr_err("%s:%s, no parent found for rate %lu.\n", + __func__, clk_hw_get_name(hw), req->rate); + return clk_hw_get_rate(hw); + } + + pr_debug("%s,rate %lu, best_parent(%s, %lu), best %lu, delta %d\n", + clk_hw_get_name(hw), req->rate, + clk_hw_get_name(best_parent_clk), best_parent_rate, + best, best_delta); + + if (req->best_parent_rate) + req->best_parent_rate = best_parent_rate; + + if (req->best_parent_hw) + req->best_parent_hw = best_parent_clk; + + return best; +} + +static int roclk_set_parent(struct clk_hw *hw, u8 index) +{ + struct pic32_ref_osc *refo = clkhw_to_refosc(hw); + unsigned long flags; + u32 v; + int err; + + if (refo->parent_map) + index = refo->parent_map[index]; + + /* wait until ACTIVE bit is zero or timeout */ + err = readl_poll_timeout(refo->ctrl_reg, v, !(v & REFO_ACTIVE), + 1, LOCK_TIMEOUT_US); + if (err) { + pr_err("%s: poll failed, clk active\n", clk_hw_get_name(hw)); + return err; + } + + spin_lock_irqsave(&refo->core->reg_lock, flags); + + pic32_syskey_unlock(); + + /* calculate & apply new */ + v = readl(refo->ctrl_reg); + v &= ~(REFO_SEL_MASK << REFO_SEL_SHIFT); + v |= index << REFO_SEL_SHIFT; + + writel(v, refo->ctrl_reg); + + spin_unlock_irqrestore(&refo->core->reg_lock, flags); + + return 0; +} + +static int roclk_set_rate_and_parent(struct clk_hw *hw, + unsigned long rate, + unsigned long parent_rate, + u8 index) +{ + struct pic32_ref_osc *refo = clkhw_to_refosc(hw); + unsigned long flags; + u32 trim, rodiv, v; + int err; + + /* calculate new rodiv & rotrim for new rate */ + roclk_calc_div_trim(rate, parent_rate, &rodiv, &trim); + + pr_debug("parent_rate = %lu, rate = %lu, div = %d, trim = %d\n", + parent_rate, rate, rodiv, trim); + + /* wait till source change is active */ + err = readl_poll_timeout(refo->ctrl_reg, v, + !(v & (REFO_ACTIVE | REFO_DIVSW_EN)), + 1, LOCK_TIMEOUT_US); + if (err) { + pr_err("%s: poll timedout, clock is still active\n", __func__); + return err; + } + + spin_lock_irqsave(&refo->core->reg_lock, flags); + v = readl(refo->ctrl_reg); + + pic32_syskey_unlock(); + + /* apply parent, if required */ + if (refo->parent_map) + index = refo->parent_map[index]; + + v &= ~(REFO_SEL_MASK << REFO_SEL_SHIFT); + v |= index << REFO_SEL_SHIFT; + + /* apply RODIV */ + v &= ~(REFO_DIV_MASK << REFO_DIV_SHIFT); + v |= rodiv << REFO_DIV_SHIFT; + writel(v, refo->ctrl_reg); + + /* apply ROTRIM */ + v = readl(refo->ctrl_reg + REFO_TRIM_REG); + v &= ~(REFO_TRIM_MASK << REFO_TRIM_SHIFT); + v |= trim << REFO_TRIM_SHIFT; + writel(v, refo->ctrl_reg + REFO_TRIM_REG); + + /* enable & activate divider switching */ + writel(REFO_ON | REFO_DIVSW_EN, PIC32_SET(refo->ctrl_reg)); + + /* wait till divswen is in-progress */ + err = readl_poll_timeout_atomic(refo->ctrl_reg, v, !(v & REFO_DIVSW_EN), + 1, LOCK_TIMEOUT_US); + /* leave the clk gated as it was */ + writel(REFO_ON, PIC32_CLR(refo->ctrl_reg)); + + spin_unlock_irqrestore(&refo->core->reg_lock, flags); + + return err; +} + +static int roclk_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + u8 index = roclk_get_parent(hw); + + return roclk_set_rate_and_parent(hw, rate, parent_rate, index); +} + +const struct clk_ops pic32_roclk_ops = { + .enable = roclk_enable, + .disable = roclk_disable, + .is_enabled = roclk_is_enabled, + .get_parent = roclk_get_parent, + .set_parent = roclk_set_parent, + .determine_rate = roclk_determine_rate, + .recalc_rate = roclk_recalc_rate, + .set_rate_and_parent = roclk_set_rate_and_parent, + .set_rate = roclk_set_rate, + .init = roclk_init, +}; + +struct clk *pic32_refo_clk_register(const struct pic32_ref_osc_data *data, + struct pic32_clk_common *core) +{ + struct pic32_ref_osc *refo; + struct clk *clk; + + refo = devm_kzalloc(core->dev, sizeof(*refo), GFP_KERNEL); + if (!refo) + return ERR_PTR(-ENOMEM); + + refo->core = core; + refo->hw.init = &data->init_data; + refo->ctrl_reg = data->ctrl_reg + core->iobase; + refo->parent_map = data->parent_map; + + clk = devm_clk_register(core->dev, &refo->hw); + if (IS_ERR(clk)) + dev_err(core->dev, "%s: clk_register() failed\n", __func__); + + return clk; +} + +struct pic32_sys_pll { + struct clk_hw hw; + void __iomem *ctrl_reg; + void __iomem *status_reg; + u32 lock_mask; + u32 idiv; /* PLL iclk divider, treated fixed */ + struct pic32_clk_common *core; +}; + +#define clkhw_to_spll(_hw) container_of(_hw, struct pic32_sys_pll, hw) + +static inline u32 spll_odiv_to_divider(u32 odiv) +{ + odiv = clamp_val(odiv, PLL_ODIV_MIN, PLL_ODIV_MAX); + + return 1 << odiv; +} + +static unsigned long spll_calc_mult_div(struct pic32_sys_pll *pll, + unsigned long rate, + unsigned long parent_rate, + u32 *mult_p, u32 *odiv_p) +{ + u32 mul, div, best_mul = 1, best_div = 1; + unsigned long new_rate, best_rate = rate; + unsigned int best_delta = -1, delta, match_found = 0; + u64 rate64; + + parent_rate /= pll->idiv; + + for (mul = 1; mul <= PLL_MULT_MAX; mul++) { + for (div = PLL_ODIV_MIN; div <= PLL_ODIV_MAX; div++) { + rate64 = parent_rate; + rate64 *= mul; + do_div(rate64, 1 << div); + new_rate = rate64; + delta = abs(rate - new_rate); + if ((new_rate >= rate) && (delta < best_delta)) { + best_delta = delta; + best_rate = new_rate; + best_mul = mul; + best_div = div; + match_found = 1; + } + } + } + + if (!match_found) { + pr_warn("spll: no match found\n"); + return 0; + } + + pr_debug("rate %lu, par_rate %lu/mult %u, div %u, best_rate %lu\n", + rate, parent_rate, best_mul, best_div, best_rate); + + if (mult_p) + *mult_p = best_mul - 1; + + if (odiv_p) + *odiv_p = best_div; + + return best_rate; +} + +static unsigned long spll_clk_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct pic32_sys_pll *pll = clkhw_to_spll(hw); + unsigned long pll_in_rate; + u32 mult, odiv, div, v; + u64 rate64; + + v = readl(pll->ctrl_reg); + odiv = ((v >> PLL_ODIV_SHIFT) & PLL_ODIV_MASK); + mult = ((v >> PLL_MULT_SHIFT) & PLL_MULT_MASK) + 1; + div = spll_odiv_to_divider(odiv); + + /* pll_in_rate = parent_rate / idiv + * pll_out_rate = pll_in_rate * mult / div; + */ + pll_in_rate = parent_rate / pll->idiv; + rate64 = pll_in_rate; + rate64 *= mult; + do_div(rate64, div); + + return rate64; +} + +static long spll_clk_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *parent_rate) +{ + struct pic32_sys_pll *pll = clkhw_to_spll(hw); + + return spll_calc_mult_div(pll, rate, *parent_rate, NULL, NULL); +} + +static int spll_clk_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct pic32_sys_pll *pll = clkhw_to_spll(hw); + unsigned long ret, flags; + u32 mult, odiv, v; + int err; + + ret = spll_calc_mult_div(pll, rate, parent_rate, &mult, &odiv); + if (!ret) + return -EINVAL; + + /* + * We can't change SPLL counters when it is in-active use + * by SYSCLK. So check before applying new counters/rate. + */ + + /* Is spll_clk active parent of sys_clk ? */ + if (unlikely(clk_hw_get_parent(pic32_sclk_hw) == hw)) { + pr_err("%s: failed, clk in-use\n", __func__); + return -EBUSY; + } + + spin_lock_irqsave(&pll->core->reg_lock, flags); + + /* apply new multiplier & divisor */ + v = readl(pll->ctrl_reg); + v &= ~(PLL_MULT_MASK << PLL_MULT_SHIFT); + v &= ~(PLL_ODIV_MASK << PLL_ODIV_SHIFT); + v |= (mult << PLL_MULT_SHIFT) | (odiv << PLL_ODIV_SHIFT); + + /* sys unlock before write */ + pic32_syskey_unlock(); + + writel(v, pll->ctrl_reg); + cpu_relax(); + + /* insert few nops (5-stage) to ensure CPU does not hang */ + cpu_nop5(); + cpu_nop5(); + + /* Wait until PLL is locked (maximum 100 usecs). */ + err = readl_poll_timeout_atomic(pll->status_reg, v, + v & pll->lock_mask, 1, 100); + spin_unlock_irqrestore(&pll->core->reg_lock, flags); + + return err; +} + +/* SPLL clock operation */ +const struct clk_ops pic32_spll_ops = { + .recalc_rate = spll_clk_recalc_rate, + .round_rate = spll_clk_round_rate, + .set_rate = spll_clk_set_rate, +}; + +struct clk *pic32_spll_clk_register(const struct pic32_sys_pll_data *data, + struct pic32_clk_common *core) +{ + struct pic32_sys_pll *spll; + struct clk *clk; + + spll = devm_kzalloc(core->dev, sizeof(*spll), GFP_KERNEL); + if (!spll) + return ERR_PTR(-ENOMEM); + + spll->core = core; + spll->hw.init = &data->init_data; + spll->ctrl_reg = data->ctrl_reg + core->iobase; + spll->status_reg = data->status_reg + core->iobase; + spll->lock_mask = data->lock_mask; + + /* cache PLL idiv; PLL driver uses it as constant.*/ + spll->idiv = (readl(spll->ctrl_reg) >> PLL_IDIV_SHIFT) & PLL_IDIV_MASK; + spll->idiv += 1; + + clk = devm_clk_register(core->dev, &spll->hw); + if (IS_ERR(clk)) + dev_err(core->dev, "sys_pll: clk_register() failed\n"); + + return clk; +} + +/* System mux clock(aka SCLK) */ + +struct pic32_sys_clk { + struct clk_hw hw; + void __iomem *mux_reg; + void __iomem *slew_reg; + u32 slew_div; + const u32 *parent_map; + struct pic32_clk_common *core; +}; + +#define clkhw_to_sys_clk(_hw) container_of(_hw, struct pic32_sys_clk, hw) + +static unsigned long sclk_get_rate(struct clk_hw *hw, unsigned long parent_rate) +{ + struct pic32_sys_clk *sclk = clkhw_to_sys_clk(hw); + u32 div; + + div = (readl(sclk->slew_reg) >> SLEW_SYSDIV_SHIFT) & SLEW_SYSDIV; + div += 1; /* sys-div to divider */ + + return parent_rate / div; +} + +static long sclk_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *parent_rate) +{ + return calc_best_divided_rate(rate, *parent_rate, SLEW_SYSDIV, 1); +} + +static int sclk_set_rate(struct clk_hw *hw, + unsigned long rate, unsigned long parent_rate) +{ + struct pic32_sys_clk *sclk = clkhw_to_sys_clk(hw); + unsigned long flags; + u32 v, div; + int err; + + div = parent_rate / rate; + + spin_lock_irqsave(&sclk->core->reg_lock, flags); + + /* apply new div */ + v = readl(sclk->slew_reg); + v &= ~(SLEW_SYSDIV << SLEW_SYSDIV_SHIFT); + v |= (div - 1) << SLEW_SYSDIV_SHIFT; + + pic32_syskey_unlock(); + + writel(v, sclk->slew_reg); + + /* wait until BUSY is cleared */ + err = readl_poll_timeout_atomic(sclk->slew_reg, v, + !(v & SLEW_BUSY), 1, LOCK_TIMEOUT_US); + + spin_unlock_irqrestore(&sclk->core->reg_lock, flags); + + return err; +} + +static u8 sclk_get_parent(struct clk_hw *hw) +{ + struct pic32_sys_clk *sclk = clkhw_to_sys_clk(hw); + u32 i, v; + + v = (readl(sclk->mux_reg) >> OSC_CUR_SHIFT) & OSC_CUR_MASK; + + if (!sclk->parent_map) + return v; + + for (i = 0; i < clk_hw_get_num_parents(hw); i++) + if (sclk->parent_map[i] == v) + return i; + return -EINVAL; +} + +static int sclk_set_parent(struct clk_hw *hw, u8 index) +{ + struct pic32_sys_clk *sclk = clkhw_to_sys_clk(hw); + unsigned long flags; + u32 nosc, cosc, v; + int err; + + spin_lock_irqsave(&sclk->core->reg_lock, flags); + + /* find new_osc */ + nosc = sclk->parent_map ? sclk->parent_map[index] : index; + + /* set new parent */ + v = readl(sclk->mux_reg); + v &= ~(OSC_NEW_MASK << OSC_NEW_SHIFT); + v |= nosc << OSC_NEW_SHIFT; + + pic32_syskey_unlock(); + + writel(v, sclk->mux_reg); + + /* initate switch */ + writel(OSC_SWEN, PIC32_SET(sclk->mux_reg)); + cpu_relax(); + + /* add nop to flush pipeline (as cpu_clk is in-flux) */ + cpu_nop5(); + + /* wait for SWEN bit to clear */ + err = readl_poll_timeout_atomic(sclk->slew_reg, v, + !(v & OSC_SWEN), 1, LOCK_TIMEOUT_US); + + spin_unlock_irqrestore(&sclk->core->reg_lock, flags); + + /* + * SCLK clock-switching logic might reject a clock switching request + * if pre-requisites (like new clk_src not present or unstable) are + * not met. + * So confirm before claiming success. + */ + cosc = (readl(sclk->mux_reg) >> OSC_CUR_SHIFT) & OSC_CUR_MASK; + if (cosc != nosc) { + pr_err("%s: err, failed to set_parent() to %d, current %d\n", + clk_hw_get_name(hw), nosc, cosc); + err = -EBUSY; + } + + return err; +} + +static void sclk_init(struct clk_hw *hw) +{ + struct pic32_sys_clk *sclk = clkhw_to_sys_clk(hw); + unsigned long flags; + u32 v; + + /* Maintain reference to this clk, required in spll_clk_set_rate() */ + pic32_sclk_hw = hw; + + /* apply slew divider on both up and down scaling */ + if (sclk->slew_div) { + spin_lock_irqsave(&sclk->core->reg_lock, flags); + v = readl(sclk->slew_reg); + v &= ~(SLEW_DIV << SLEW_DIV_SHIFT); + v |= sclk->slew_div << SLEW_DIV_SHIFT; + v |= SLEW_DOWNEN | SLEW_UPEN; + writel(v, sclk->slew_reg); + spin_unlock_irqrestore(&sclk->core->reg_lock, flags); + } +} + +/* sclk with post-divider */ +const struct clk_ops pic32_sclk_ops = { + .get_parent = sclk_get_parent, + .set_parent = sclk_set_parent, + .round_rate = sclk_round_rate, + .set_rate = sclk_set_rate, + .recalc_rate = sclk_get_rate, + .init = sclk_init, + .determine_rate = __clk_mux_determine_rate, +}; + +/* sclk with no slew and no post-divider */ +const struct clk_ops pic32_sclk_no_div_ops = { + .get_parent = sclk_get_parent, + .set_parent = sclk_set_parent, + .init = sclk_init, + .determine_rate = __clk_mux_determine_rate, +}; + +struct clk *pic32_sys_clk_register(const struct pic32_sys_clk_data *data, + struct pic32_clk_common *core) +{ + struct pic32_sys_clk *sclk; + struct clk *clk; + + sclk = devm_kzalloc(core->dev, sizeof(*sclk), GFP_KERNEL); + if (!sclk) + return ERR_PTR(-ENOMEM); + + sclk->core = core; + sclk->hw.init = &data->init_data; + sclk->mux_reg = data->mux_reg + core->iobase; + sclk->slew_reg = data->slew_reg + core->iobase; + sclk->slew_div = data->slew_div; + sclk->parent_map = data->parent_map; + + clk = devm_clk_register(core->dev, &sclk->hw); + if (IS_ERR(clk)) + dev_err(core->dev, "%s: clk register failed\n", __func__); + + return clk; +} + +/* secondary oscillator */ +struct pic32_sec_osc { + struct clk_hw hw; + void __iomem *enable_reg; + void __iomem *status_reg; + u32 enable_mask; + u32 status_mask; + unsigned long fixed_rate; + struct pic32_clk_common *core; +}; + +#define clkhw_to_sosc(_hw) container_of(_hw, struct pic32_sec_osc, hw) +static int sosc_clk_enable(struct clk_hw *hw) +{ + struct pic32_sec_osc *sosc = clkhw_to_sosc(hw); + u32 v; + + /* enable SOSC */ + pic32_syskey_unlock(); + writel(sosc->enable_mask, PIC32_SET(sosc->enable_reg)); + + /* wait till warm-up period expires or ready-status is updated */ + return readl_poll_timeout_atomic(sosc->status_reg, v, + v & sosc->status_mask, 1, 100); +} + +static void sosc_clk_disable(struct clk_hw *hw) +{ + struct pic32_sec_osc *sosc = clkhw_to_sosc(hw); + + pic32_syskey_unlock(); + writel(sosc->enable_mask, PIC32_CLR(sosc->enable_reg)); +} + +static int sosc_clk_is_enabled(struct clk_hw *hw) +{ + struct pic32_sec_osc *sosc = clkhw_to_sosc(hw); + u32 enabled, ready; + + /* check enabled and ready status */ + enabled = readl(sosc->enable_reg) & sosc->enable_mask; + ready = readl(sosc->status_reg) & sosc->status_mask; + + return enabled && ready; +} + +static unsigned long sosc_clk_calc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + return clkhw_to_sosc(hw)->fixed_rate; +} + +const struct clk_ops pic32_sosc_ops = { + .enable = sosc_clk_enable, + .disable = sosc_clk_disable, + .is_enabled = sosc_clk_is_enabled, + .recalc_rate = sosc_clk_calc_rate, +}; + +struct clk *pic32_sosc_clk_register(const struct pic32_sec_osc_data *data, + struct pic32_clk_common *core) +{ + struct pic32_sec_osc *sosc; + + sosc = devm_kzalloc(core->dev, sizeof(*sosc), GFP_KERNEL); + if (!sosc) + return ERR_PTR(-ENOMEM); + + sosc->core = core; + sosc->hw.init = &data->init_data; + sosc->fixed_rate = data->fixed_rate; + sosc->enable_mask = data->enable_mask; + sosc->status_mask = data->status_mask; + sosc->enable_reg = data->enable_reg + core->iobase; + sosc->status_reg = data->status_reg + core->iobase; + + return devm_clk_register(core->dev, &sosc->hw); +} |