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Date: Fri, 6 May 2016 17:10:56 -0700
From: Stephen Boyd <sboyd@...eaurora.org>
To: Purna Chandra Mandal <purna.mandal@...rochip.com>
Cc: linux-kernel@...r.kernel.org, linux-mips@...ux-mips.org,
Joshua Henderson <digitalpeer@...italpeer.com>,
Michael Turquette <mturquette@...libre.com>,
Ralf Baechle <ralf@...ux-mips.org>, linux-clk@...r.kernel.org
Subject: Re: [PATCH v10 2/3] clk: microchip: Add PIC32 clock driver
Mostly nitpicks, although I'm worried about the iomem casting and
addition stuff. I suppose if those are fixed up at some later
time then I'm fine with this going through MIPS tree.
On 03/23, Purna Chandra Mandal wrote:
> +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_atomic(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(&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(&lock, flags);
> +
> + /* wait again, for pbdivready */
> + err = readl_poll_timeout_atomic(pb->ctrl_reg, v, v & PB_DIV_READY,
> + 1, LOCK_TIMEOUT_US);
why atomic? The spinlock was released already.
> + 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(struct pic32_periph_clk *pbclk,
> + void __iomem *clk_iobase)
> +{
> + struct clk *clk;
> +
> + pbclk->ctrl_reg += (ulong)clk_iobase;
> +
> + clk = clk_register(NULL, &pbclk->hw);
> + if (IS_ERR(clk)) {
> + pr_err("%s: clk_register() failed\n", __func__);
> + return clk;
> + }
> +
> + return clk;
These two last lines are the same, just print an error and always
return clk.
> +}
> +
> +/* Reference Oscillator operations */
> +#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->regs) & 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->regs));
> + 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->regs));
> +}
> +
> +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->regs) >> REFO_SEL_SHIFT) & REFO_SEL_MASK;
> +
> + if (!refo->parent_map)
> + return (u8)v;
> +
> + for (i = 0; i < clk_hw_get_num_parents(hw); i++)
> + if (refo->parent_map[i] == v)
> + return (u8)i;
That cast is implicit already.
> +
> + 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 (unsigned long)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->regs);
> + rodiv = (v >> REFO_DIV_SHIFT) & REFO_DIV_MASK;
> +
> + /* get trim */
> + v = readl(refo->regs + 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);
> + best_parent_clk = clk_hw_get_parent(hw);
> + best_parent_rate = clk_hw_get_rate(best_parent_clk);
The core would already fill these things in by default so we
don't really need to get it again.
> + best = 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_atomic(refo->regs, v, !(v & REFO_ACTIVE),
Why atomic?
> + 1, LOCK_TIMEOUT_US);
> + if (err) {
> + pr_err("%s: poll failed, clk active\n", clk_hw_get_name(hw));
> + return err;
> + }
> +
> + spin_lock_irqsave(&lock, flags);
> +
> + pic32_syskey_unlock();
> +
> + /* calculate & apply new */
> + v = readl(refo->regs);
> + v &= ~(REFO_SEL_MASK << REFO_SEL_SHIFT);
> + v |= index << REFO_SEL_SHIFT;
> +
> + writel(v, refo->regs);
> +
> + spin_unlock_irqrestore(&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_atomic(refo->regs, v,
Why atomic?
> + !(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(&lock, flags);
> + v = readl(refo->regs);
> +
> + 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->regs);
> +
> + /* apply ROTRIM */
> + v = readl(refo->regs + REFO_TRIM_REG);
> + v &= ~(REFO_TRIM_MASK << REFO_TRIM_SHIFT);
> + v |= trim << REFO_TRIM_SHIFT;
> + writel(v, refo->regs + REFO_TRIM_REG);
> +
> + /* enable & activate divider switching */
> + writel(REFO_ON | REFO_DIVSW_EN, PIC32_SET(refo->regs));
> +
> + /* wait till divswen is in-progress */
> + err = readl_poll_timeout_atomic(refo->regs, v, !(v & REFO_DIVSW_EN),
> + 1, LOCK_TIMEOUT_US);
> + /* leave the clk gated as it was */
> + writel(REFO_ON, PIC32_CLR(refo->regs));
> +
> + spin_unlock_irqrestore(&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(struct pic32_ref_osc *refo,
> + void __iomem *clk_iobase)
> +{
> + struct clk *clk;
> +
> + refo->regs += (ulong)clk_iobase;
What happens if we do this and then the driver probe fails for
some weird reason and we retry probe later? The whole += thing is
not very appealing to me. We probably need some sort of
descriptor structure that we generate the final structure out of
and populate any required fields with.
> +
> + clk = clk_register(NULL, &refo->hw);
> + if (IS_ERR(clk)) {
> + pr_err("%s: clk_register() failed\n", __func__);
> + return clk;
> + }
> +
> + return clk;
> +}
> +
> +#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 = (u32)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 (unsigned long)rate64;
Cast is useless (it's implicit).
> +}
> +
> +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 system clock. So ensure that PLL clock is not active
> + * parent of SYSCLK before applying new counter/rate.
> + */
> +
> + /* Is spll_clk active parent of sys_clk ? */
> + if (unlikely(clk_hw_get_parent(pic32_sclk_hw) == hw)) {
Why can't we use CLK_SET_RATE_GATE here?
> + pr_err("%s: failed, clk in-use\n", __func__);
> + return -EBUSY;
> + }
> +
> + spin_lock_irqsave(&lock, flags);
> +
> + /* apply new multiplier & divisor (read-modify-write) */
> + 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);
> +
> diff --git a/drivers/clk/microchip/clk-core.h b/drivers/clk/microchip/clk-core.h
> new file mode 100644
> index 0000000..276869a
> --- /dev/null
> +++ b/drivers/clk/microchip/clk-core.h
> @@ -0,0 +1,78 @@
> +/*
> + * Purna Chandra Mandal,<purna.mandal@...rochip.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.
> + */
> +#ifndef __MICROCHIP_CLK_PIC32_H_
> +#define __MICROCHIP_CLK_PIC32_H_
> +
> +struct clk_hw;
Not sure why we forward declare this. struct clk_hw is not used
as a pointer below, so we really need to include clk-provider.h
here.
> +
> +/* System PLL clock */
> +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 */
> +};
> +
[..]
> +#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 0000000..e92e581
> --- /dev/null
> +++ b/drivers/clk/microchip/clk-pic32mzda.c
> @@ -0,0 +1,240 @@
> +/*
> + * Purna Chandra Mandal,<purna.mandal@...rochip.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-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"
> +
> +static void __iomem *pic32_clk_iobase;
> +static DEFINE_SPINLOCK(lock);
Please use a better name. pic32_clk_lock? That way when we get
the lockdep info it doesn't say 'lock'.
> +
> +/* FRC Postscaler */
> +#define OSC_FRCDIV_MASK 0x07
> +#define OSC_FRCDIV_SHIFT 24
> +
> +/* SPLL fields */
> +#define PLL_ICLK_MASK 0x01
> +#define PLL_ICLK_SHIFT 7
> +
[...]
> +
> +static struct pic32_sec_osc sosc_clk = {
> + .enable_reg = (void __iomem *)0x0,
> + .status_reg = (void __iomem *)0x1d0,
> + .enable_bitmask = BIT(1),
> + .status_bitmask = BIT(4),
> + .hw.init = &(struct clk_init_data) {
> + .name = "sosc_clk",
> + .parent_names = NULL,
> + .num_parents = 0,
This is static data so = 0 is pretty useless.
> + .flags = CLK_IS_ROOT,
This flag is going away. Please don't use it.
> + .ops = &pic32_sosc_ops,
> + },
> +};
> +
> +static int pic32_fscm_nmi(struct notifier_block *nb,
> + unsigned long action, void *data)
> +{
> + if (readl(pic32_clk_iobase) & BIT(2))
Why can't we pass this to the notifier by making a wrapper
structure to hold the iomem pointer and notifier block? That way
we don't have a static global for this iomem region.
> + pr_err("pic32-clk: FSCM detected clk failure.\n");
That's it? No recovery? Is this for debugging (i.e. pr_debug)?
> +
> + return NOTIFY_OK;
> +}
> +
> +static struct notifier_block failsafe_clk_notifier = {
pic32_failsafe_clk_notifier?
> + .notifier_call = pic32_fscm_nmi,
> +};
> +
> +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;
> + static struct clk_onecell_data onecell_data;
> + static struct clk *clks[MAXCLKS];
> + struct clk *pll_mux_clk;
> + int nr_clks = 0, i;
> +
> + pic32_clk_iobase = of_io_request_and_map(np, 0, of_node_full_name(np));
> + if (IS_ERR(pic32_clk_iobase))
> + panic("pic32-clk: failed to map registers\n");
Just return an error? Panic in probe is not too nice.
> +
> + /* register fixed rate clocks */
> + clks[POSCCLK] = clk_register_fixed_rate(NULL, "posc_clk", NULL,
> + CLK_IS_ROOT, 24000000);
> + clks[FRCCLK] = clk_register_fixed_rate(NULL, "frc_clk", NULL,
> + CLK_IS_ROOT, 8000000);
> + clks[BFRCCLK] = clk_register_fixed_rate(NULL, "bfrc_clk", NULL,
> + CLK_IS_ROOT, 8000000);
> + clks[LPRCCLK] = clk_register_fixed_rate(NULL, "lprc_clk", NULL,
> + CLK_IS_ROOT, 32000);
> + clks[UPLLCLK] = clk_register_fixed_rate(NULL, "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,
> + pic32_clk_iobase);
> + }
> + /* divider clock */
> + clks[FRCDIVCLK] = clk_register_divider(NULL, "frcdiv_clk",
> + "frc_clk", 0,
> + pic32_clk_iobase,
> + OSC_FRCDIV_SHIFT,
> + OSC_FRCDIV_MASK,
> + CLK_DIVIDER_POWER_OF_TWO,
> + &lock);
> + /* PLL ICLK mux */
> + pll_mux_clk = clk_register_mux(NULL, "spll_mux_clk",
Please pass device to register functions. Who knows, we may
start using that someday.
> + pll_mux_parents, 2, 0,
> + pic32_clk_iobase + 0x020,
> + PLL_ICLK_SHIFT, 1, 0, &lock);
> + if (IS_ERR(pll_mux_clk))
> + panic("spll_mux_clk: clk register failed\n");
> + /* PLL */
> + clks[PLLCLK] = pic32_spll_clk_register(&sys_pll, pic32_clk_iobase);
> + /* SYSTEM clock */
> + clks[SCLK] = pic32_sys_clk_register(&sys_mux_clk, pic32_clk_iobase);
> + /* 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],
> + pic32_clk_iobase);
> +
> + /* 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],
> + pic32_clk_iobase);
> + /* 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 */
> + onecell_data.clks = clks;
> + onecell_data.clk_num = MAXCLKS;
> + of_clk_add_provider(np, of_clk_src_onecell_get, &onecell_data);
Check for errors please.
> +
> + /* register NMI for failsafe clock monitor */
> + return register_nmi_notifier(&failsafe_clk_notifier);
> +}
--
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