diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/clk/microchip/Makefile | 3 | ||||
| -rw-r--r-- | drivers/clk/microchip/clk-core.c | 1028 | ||||
| -rw-r--r-- | drivers/clk/microchip/clk-core.h | 76 | ||||
| -rw-r--r-- | drivers/clk/microchip/clk-pic32mzda.c | 269 |
4 files changed, 1376 insertions, 0 deletions
diff --git a/drivers/clk/microchip/Makefile b/drivers/clk/microchip/Makefile new file mode 100644 index 000000000..f34b247e8 --- /dev/null +++ b/drivers/clk/microchip/Makefile @@ -0,0 +1,3 @@ +# SPDX-License-Identifier: GPL-2.0-only +obj-$(CONFIG_COMMON_CLK_PIC32) += clk-core.o +obj-$(CONFIG_PIC32MZDA) += clk-pic32mzda.o diff --git a/drivers/clk/microchip/clk-core.c b/drivers/clk/microchip/clk-core.c new file mode 100644 index 000000000..1b4f023cd --- /dev/null +++ b/drivers/clk/microchip/clk-core.c @@ -0,0 +1,1028 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Purna Chandra Mandal,<purna.mandal@microchip.com> + * Copyright (C) 2015 Microchip Technology Inc. All rights reserved. + */ +#include <linux/clk-provider.h> +#include <linux/delay.h> +#include <linux/device.h> +#include <linux/interrupt.h> +#include <linux/io.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 int roclk_init(struct clk_hw *hw) +{ + /* initialize clock in disabled state */ + roclk_disable(hw); + + return 0; +} + +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 int 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); + } + + return 0; +} + +/* 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); +} diff --git a/drivers/clk/microchip/clk-core.h b/drivers/clk/microchip/clk-core.h new file mode 100644 index 000000000..acb81739a --- /dev/null +++ b/drivers/clk/microchip/clk-core.h @@ -0,0 +1,76 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Purna Chandra Mandal,<purna.mandal@microchip.com> + * Copyright (C) 2015 Microchip Technology Inc. All rights reserved. + */ +#ifndef __MICROCHIP_CLK_PIC32_H_ +#define __MICROCHIP_CLK_PIC32_H_ + +#include <linux/clk-provider.h> + +/* PIC32 clock data */ +struct pic32_clk_common { + struct device *dev; + void __iomem *iobase; + spinlock_t reg_lock; /* clock lock */ +}; + +/* System PLL clock */ +struct pic32_sys_pll_data { + struct clk_init_data init_data; + const u32 ctrl_reg; + const u32 status_reg; + const u32 lock_mask; +}; + +/* System clock */ +struct pic32_sys_clk_data { + struct clk_init_data init_data; + const u32 mux_reg; + const u32 slew_reg; + const u32 *parent_map; + const u32 slew_div; +}; + +/* Reference Oscillator clock */ +struct pic32_ref_osc_data { + struct clk_init_data init_data; + const u32 ctrl_reg; + const u32 *parent_map; +}; + +/* Peripheral Bus clock */ +struct pic32_periph_clk_data { + struct clk_init_data init_data; + const u32 ctrl_reg; +}; + +/* External Secondary Oscillator clock */ +struct pic32_sec_osc_data { + struct clk_init_data init_data; + const u32 enable_reg; + const u32 status_reg; + const u32 enable_mask; + const u32 status_mask; + const unsigned long fixed_rate; +}; + +extern const struct clk_ops pic32_pbclk_ops; +extern const struct clk_ops pic32_sclk_ops; +extern const struct clk_ops pic32_sclk_no_div_ops; +extern const struct clk_ops pic32_spll_ops; +extern const struct clk_ops pic32_roclk_ops; +extern const struct clk_ops pic32_sosc_ops; + +struct clk *pic32_periph_clk_register(const struct pic32_periph_clk_data *data, + struct pic32_clk_common *core); +struct clk *pic32_refo_clk_register(const struct pic32_ref_osc_data *data, + struct pic32_clk_common *core); +struct clk *pic32_sys_clk_register(const struct pic32_sys_clk_data *data, + struct pic32_clk_common *core); +struct clk *pic32_spll_clk_register(const struct pic32_sys_pll_data *data, + struct pic32_clk_common *core); +struct clk *pic32_sosc_clk_register(const struct pic32_sec_osc_data *data, + struct pic32_clk_common *core); + +#endif /* __MICROCHIP_CLK_PIC32_H_*/ diff --git a/drivers/clk/microchip/clk-pic32mzda.c b/drivers/clk/microchip/clk-pic32mzda.c new file mode 100644 index 000000000..b72c76f9e --- /dev/null +++ b/drivers/clk/microchip/clk-pic32mzda.c @@ -0,0 +1,269 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Purna Chandra Mandal,<purna.mandal@microchip.com> + * Copyright (C) 2015 Microchip Technology Inc. All rights reserved. + */ +#include <dt-bindings/clock/microchip,pic32-clock.h> +#include <linux/clk.h> +#include <linux/clk-provider.h> +#include <linux/clkdev.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/of_address.h> +#include <linux/of_platform.h> +#include <linux/platform_device.h> +#include <asm/traps.h> + +#include "clk-core.h" + +/* FRC Postscaler */ +#define OSC_FRCDIV_MASK 0x07 +#define OSC_FRCDIV_SHIFT 24 + +/* SPLL fields */ +#define PLL_ICLK_MASK 0x01 +#define PLL_ICLK_SHIFT 7 + +#define DECLARE_PERIPHERAL_CLOCK(__clk_name, __reg, __flags) \ + { \ + .ctrl_reg = (__reg), \ + .init_data = { \ + .name = (__clk_name), \ + .parent_names = (const char *[]) { \ + "sys_clk" \ + }, \ + .num_parents = 1, \ + .ops = &pic32_pbclk_ops, \ + .flags = (__flags), \ + }, \ + } + +#define DECLARE_REFO_CLOCK(__clkid, __reg) \ + { \ + .ctrl_reg = (__reg), \ + .init_data = { \ + .name = "refo" #__clkid "_clk", \ + .parent_names = (const char *[]) { \ + "sys_clk", "pb1_clk", "posc_clk", \ + "frc_clk", "lprc_clk", "sosc_clk", \ + "sys_pll", "refi" #__clkid "_clk", \ + "bfrc_clk", \ + }, \ + .num_parents = 9, \ + .flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE,\ + .ops = &pic32_roclk_ops, \ + }, \ + .parent_map = (const u32[]) { \ + 0, 1, 2, 3, 4, 5, 7, 8, 9 \ + }, \ + } + +static const struct pic32_ref_osc_data ref_clks[] = { + DECLARE_REFO_CLOCK(1, 0x80), + DECLARE_REFO_CLOCK(2, 0xa0), + DECLARE_REFO_CLOCK(3, 0xc0), + DECLARE_REFO_CLOCK(4, 0xe0), + DECLARE_REFO_CLOCK(5, 0x100), +}; + +static const struct pic32_periph_clk_data periph_clocks[] = { + DECLARE_PERIPHERAL_CLOCK("pb1_clk", 0x140, 0), + DECLARE_PERIPHERAL_CLOCK("pb2_clk", 0x150, CLK_IGNORE_UNUSED), + DECLARE_PERIPHERAL_CLOCK("pb3_clk", 0x160, 0), + DECLARE_PERIPHERAL_CLOCK("pb4_clk", 0x170, 0), + DECLARE_PERIPHERAL_CLOCK("pb5_clk", 0x180, 0), + DECLARE_PERIPHERAL_CLOCK("pb6_clk", 0x190, 0), + DECLARE_PERIPHERAL_CLOCK("cpu_clk", 0x1a0, CLK_IGNORE_UNUSED), +}; + +static const struct pic32_sys_clk_data sys_mux_clk = { + .slew_reg = 0x1c0, + .slew_div = 2, /* step of div_4 -> div_2 -> no_div */ + .init_data = { + .name = "sys_clk", + .parent_names = (const char *[]) { + "frcdiv_clk", "sys_pll", "posc_clk", + "sosc_clk", "lprc_clk", "frcdiv_clk", + }, + .num_parents = 6, + .ops = &pic32_sclk_ops, + }, + .parent_map = (const u32[]) { + 0, 1, 2, 4, 5, 7, + }, +}; + +static const struct pic32_sys_pll_data sys_pll = { + .ctrl_reg = 0x020, + .status_reg = 0x1d0, + .lock_mask = BIT(7), + .init_data = { + .name = "sys_pll", + .parent_names = (const char *[]) { + "spll_mux_clk" + }, + .num_parents = 1, + .ops = &pic32_spll_ops, + }, +}; + +static const struct pic32_sec_osc_data sosc_clk = { + .status_reg = 0x1d0, + .enable_mask = BIT(1), + .status_mask = BIT(4), + .fixed_rate = 32768, + .init_data = { + .name = "sosc_clk", + .parent_names = NULL, + .ops = &pic32_sosc_ops, + }, +}; + +static int pic32mzda_critical_clks[] = { + PB2CLK, PB7CLK +}; + +/* PIC32MZDA clock data */ +struct pic32mzda_clk_data { + struct clk *clks[MAXCLKS]; + struct pic32_clk_common core; + struct clk_onecell_data onecell_data; + struct notifier_block failsafe_notifier; +}; + +static int pic32_fscm_nmi(struct notifier_block *nb, + unsigned long action, void *data) +{ + struct pic32mzda_clk_data *cd; + + cd = container_of(nb, struct pic32mzda_clk_data, failsafe_notifier); + + /* SYSCLK is now running from BFRCCLK. Report clock failure. */ + if (readl(cd->core.iobase) & BIT(2)) + pr_alert("pic32-clk: FSCM detected clk failure.\n"); + + /* TODO: detect reason of failure and recover accordingly */ + + return NOTIFY_OK; +} + +static int pic32mzda_clk_probe(struct platform_device *pdev) +{ + const char *const pll_mux_parents[] = {"posc_clk", "frc_clk"}; + struct device_node *np = pdev->dev.of_node; + struct pic32mzda_clk_data *cd; + struct pic32_clk_common *core; + struct clk *pll_mux_clk, *clk; + struct clk **clks; + int nr_clks, i, ret; + + cd = devm_kzalloc(&pdev->dev, sizeof(*cd), GFP_KERNEL); + if (!cd) + return -ENOMEM; + + core = &cd->core; + core->iobase = of_io_request_and_map(np, 0, of_node_full_name(np)); + if (IS_ERR(core->iobase)) { + dev_err(&pdev->dev, "pic32-clk: failed to map registers\n"); + return PTR_ERR(core->iobase); + } + + spin_lock_init(&core->reg_lock); + core->dev = &pdev->dev; + clks = &cd->clks[0]; + + /* register fixed rate clocks */ + clks[POSCCLK] = clk_register_fixed_rate(&pdev->dev, "posc_clk", NULL, + 0, 24000000); + clks[FRCCLK] = clk_register_fixed_rate(&pdev->dev, "frc_clk", NULL, + 0, 8000000); + clks[BFRCCLK] = clk_register_fixed_rate(&pdev->dev, "bfrc_clk", NULL, + 0, 8000000); + clks[LPRCCLK] = clk_register_fixed_rate(&pdev->dev, "lprc_clk", NULL, + 0, 32000); + clks[UPLLCLK] = clk_register_fixed_rate(&pdev->dev, "usbphy_clk", NULL, + 0, 24000000); + /* fixed rate (optional) clock */ + if (of_find_property(np, "microchip,pic32mzda-sosc", NULL)) { + pr_info("pic32-clk: dt requests SOSC.\n"); + clks[SOSCCLK] = pic32_sosc_clk_register(&sosc_clk, core); + } + /* divider clock */ + clks[FRCDIVCLK] = clk_register_divider(&pdev->dev, "frcdiv_clk", + "frc_clk", 0, + core->iobase, + OSC_FRCDIV_SHIFT, + OSC_FRCDIV_MASK, + CLK_DIVIDER_POWER_OF_TWO, + &core->reg_lock); + /* PLL ICLK mux */ + pll_mux_clk = clk_register_mux(&pdev->dev, "spll_mux_clk", + pll_mux_parents, 2, 0, + core->iobase + 0x020, + PLL_ICLK_SHIFT, 1, 0, &core->reg_lock); + if (IS_ERR(pll_mux_clk)) + pr_err("spll_mux_clk: clk register failed\n"); + + /* PLL */ + clks[PLLCLK] = pic32_spll_clk_register(&sys_pll, core); + /* SYSTEM clock */ + clks[SCLK] = pic32_sys_clk_register(&sys_mux_clk, core); + /* Peripheral bus clocks */ + for (nr_clks = PB1CLK, i = 0; nr_clks <= PB7CLK; i++, nr_clks++) + clks[nr_clks] = pic32_periph_clk_register(&periph_clocks[i], + core); + /* Reference oscillator clock */ + for (nr_clks = REF1CLK, i = 0; nr_clks <= REF5CLK; i++, nr_clks++) + clks[nr_clks] = pic32_refo_clk_register(&ref_clks[i], core); + + /* register clkdev */ + for (i = 0; i < MAXCLKS; i++) { + if (IS_ERR(clks[i])) + continue; + clk_register_clkdev(clks[i], NULL, __clk_get_name(clks[i])); + } + + /* register clock provider */ + cd->onecell_data.clks = clks; + cd->onecell_data.clk_num = MAXCLKS; + ret = of_clk_add_provider(np, of_clk_src_onecell_get, + &cd->onecell_data); + if (ret) + return ret; + + /* force enable critical clocks */ + for (i = 0; i < ARRAY_SIZE(pic32mzda_critical_clks); i++) { + clk = clks[pic32mzda_critical_clks[i]]; + if (clk_prepare_enable(clk)) + dev_err(&pdev->dev, "clk_prepare_enable(%s) failed\n", + __clk_get_name(clk)); + } + + /* register NMI for failsafe clock monitor */ + cd->failsafe_notifier.notifier_call = pic32_fscm_nmi; + return register_nmi_notifier(&cd->failsafe_notifier); +} + +static const struct of_device_id pic32mzda_clk_match_table[] = { + { .compatible = "microchip,pic32mzda-clk", }, + { } +}; +MODULE_DEVICE_TABLE(of, pic32mzda_clk_match_table); + +static struct platform_driver pic32mzda_clk_driver = { + .probe = pic32mzda_clk_probe, + .driver = { + .name = "clk-pic32mzda", + .of_match_table = pic32mzda_clk_match_table, + }, +}; + +static int __init microchip_pic32mzda_clk_init(void) +{ + return platform_driver_register(&pic32mzda_clk_driver); +} +core_initcall(microchip_pic32mzda_clk_init); + +MODULE_DESCRIPTION("Microchip PIC32MZDA Clock Driver"); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS("platform:clk-pic32mzda"); |