--- /dev/null
+/*
+ * 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 pbdivready */
+ err = readl_poll_timeout_atomic(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);
+}
--- /dev/null
+/*
+ * 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 <dt-bindings/clock/microchip,pic32-clock.h>
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/clkdev.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),
+ .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,
+ CLK_IS_ROOT, 24000000);
+ clks[FRCCLK] = clk_register_fixed_rate(&pdev->dev, "frc_clk", NULL,
+ CLK_IS_ROOT, 8000000);
+ clks[BFRCCLK] = clk_register_fixed_rate(&pdev->dev, "bfrc_clk", NULL,
+ CLK_IS_ROOT, 8000000);
+ clks[LPRCCLK] = clk_register_fixed_rate(&pdev->dev, "lprc_clk", NULL,
+ CLK_IS_ROOT, 32000);
+ clks[UPLLCLK] = clk_register_fixed_rate(&pdev->dev, "usbphy_clk", NULL,
+ CLK_IS_ROOT, 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");
projects / kernel.git / commitdiff