From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nicolas Ferre Subject: Re: [PATCH v3 13/19] clk: at91: add PMC programmable clocks Date: Tue, 8 Oct 2013 18:06:37 +0200 Message-ID: <52542D8D.1030006@atmel.com> References: <1375937608-3773-1-git-send-email-b.brezillon@overkiz.com> <1375945938-9614-1-git-send-email-b.brezillon@overkiz.com> <52542CA9.2000105@atmel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <52542CA9.2000105-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Nicolas Ferre , Boris BREZILLON , Grant Likely , Rob Herring , Rob Landley , Andrew Victor , Jean-Christophe Plagniol-Villard , Russell King , Mike Turquette , Felipe Balbi , Greg Kroah-Hartman , Ludovic Desroches , Josh Wu , Richard Genoud Cc: devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org List-Id: devicetree@vger.kernel.org On 08/10/2013 18:02, Nicolas Ferre : > On 08/08/2013 09:12, Boris BREZILLON : >> This patch adds new at91 programmable clocks implementation using common clk >> framework. >> A programmable clock is a clock which can be exported on a given pin to clock >> external devices. >> Each programmable clock is given an id (from 0 to 8). >> The number of available programmable clocks depends on the SoC you're using. >> Programmable clock driver only implements the clock setting (clock rate and >> parent setting). It must be chained to a system clock in order to >> enable/disable the generated clock. >> The PCKX pins used to output the clock signals must be assigned to the >> appropriate peripheral (see atmel's datasheets). >> >> Signed-off-by: Boris BREZILLON >> --- >> drivers/clk/at91/Makefile | 2 + >> drivers/clk/at91/clk-programmable.c | 419 +++++++++++++++++++++++++++++++++++ >> drivers/clk/at91/pmc.c | 15 ++ >> drivers/clk/at91/pmc.h | 9 + >> 4 files changed, 445 insertions(+) >> create mode 100644 drivers/clk/at91/clk-programmable.c >> >> diff --git a/drivers/clk/at91/Makefile b/drivers/clk/at91/Makefile >> index 04deba3..3873b62 100644 >> --- a/drivers/clk/at91/Makefile >> +++ b/drivers/clk/at91/Makefile >> @@ -5,3 +5,5 @@ >> obj-y += pmc.o >> obj-y += clk-main.o clk-pll.o clk-plldiv.o clk-master.o >> obj-y += clk-system.o clk-peripheral.o >> + >> +obj-$(CONFIG_AT91_PROGRAMMABLE_CLOCKS) += clk-programmable.o >> diff --git a/drivers/clk/at91/clk-programmable.c b/drivers/clk/at91/clk-programmable.c >> new file mode 100644 >> index 0000000..f40de6a >> --- /dev/null >> +++ b/drivers/clk/at91/clk-programmable.c >> @@ -0,0 +1,419 @@ >> +/* >> + * drivers/clk/at91/clk-programmable.c >> + * >> + * Copyright (C) 2013 Boris BREZILLON >> + * >> + * This program is free software; you can redistribute it and/or modify >> + * it under the terms of the GNU General Public License as published by >> + * the Free Software Foundation; either version 2 of the License, or >> + * (at your option) any later version. >> + * >> + */ >> + >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> + >> +#include "pmc.h" >> + >> +#define PROG_SOURCE_MAX 5 >> +#define PROG_MAX 8 >> + >> +struct clk_programmable_layout { >> + u8 pres_shift; >> + u8 css_mask; >> + u8 have_slck_mck; >> +}; >> + >> +#define to_clk_programmable(hw) container_of(hw, struct clk_programmable, hw) >> +struct clk_programmable { >> + struct clk_hw hw; >> + struct at91_pmc *pmc; >> + unsigned int irq; >> + wait_queue_head_t wait; >> + u8 id; >> + u8 css; >> + u8 pres; >> + u8 slckmck; >> + const struct clk_programmable_layout *layout; >> +}; >> + >> +static irqreturn_t clk_programmable_irq_handler(int irq, void *dev_id) >> +{ >> + struct clk_programmable *prog = (struct clk_programmable *)dev_id; >> + >> + wake_up(&prog->wait); >> + >> + return IRQ_HANDLED; >> +} >> + >> +static int clk_programmable_prepare(struct clk_hw *hw) >> +{ >> + u32 tmp; >> + struct clk_programmable *prog = to_clk_programmable(hw); >> + struct at91_pmc *pmc = prog->pmc; >> + const struct clk_programmable_layout *layout = prog->layout; >> + >> + tmp = prog->css | (prog->pres << layout->pres_shift); >> + if (layout->have_slck_mck && prog->slckmck) >> + tmp |= 1 << 8; > > ;-) => define constants > >> + >> + pmc_write(pmc, AT91_PMC_PCKR(prog->id), tmp); >> + >> + while (!(pmc_read(pmc, AT91_PMC_SR) & (1 << (prog->id + 8)))) > > - create a macro > - is creating an event for each iteration of the while loop a good idea? Oops, it is not "creating" it is "waiting" which is pretty different ;-) So, do not consider this remark. > - for the while() loop, I would like a timeout and a a non-active wait > function... Okay, this is also false: sorry for the noise. > >> + wait_event(prog->wait, >> + pmc_read(pmc, AT91_PMC_SR) & (1 << (prog->id + 8))); >> + >> + return 0; >> +} >> + >> +static int clk_programmable_is_ready(struct clk_hw *hw) >> +{ >> + struct clk_programmable *prog = to_clk_programmable(hw); >> + struct at91_pmc *pmc = prog->pmc; >> + >> + return !!(pmc_read(pmc, AT91_PMC_SR) & (1 << (prog->id + 8))); > > Ditto > >> +} >> + >> +static unsigned long clk_programmable_recalc_rate(struct clk_hw *hw, >> + unsigned long parent_rate) >> +{ >> + u32 tmp; >> + struct clk_programmable *prog = to_clk_programmable(hw); >> + struct at91_pmc *pmc = prog->pmc; >> + const struct clk_programmable_layout *layout = prog->layout; >> + >> + tmp = pmc_read(pmc, AT91_PMC_PCKR(prog->id)); >> + prog->pres = (tmp >> layout->pres_shift) & 0x7; > > define constants > >> + >> + return parent_rate >> prog->pres; >> +} >> + >> +static long clk_programmable_round_rate(struct clk_hw *hw, unsigned long rate, >> + unsigned long *parent_rate) >> +{ >> + unsigned long best_rate = *parent_rate; >> + unsigned long best_diff; >> + unsigned long new_diff; >> + unsigned long cur_rate; >> + int shift = shift; >> + >> + if (rate > *parent_rate) >> + return *parent_rate; >> + else >> + best_diff = *parent_rate - rate; >> + >> + if (!best_diff) >> + return best_rate; >> + >> + for (shift = 1; shift < 7; shift++) { > > Ditto > >> + cur_rate = *parent_rate >> shift; >> + >> + if (cur_rate > rate) >> + new_diff = cur_rate - rate; >> + else >> + new_diff = rate - cur_rate; >> + >> + if (!new_diff) >> + return cur_rate; >> + >> + if (new_diff < best_diff) { >> + best_diff = new_diff; >> + best_rate = cur_rate; >> + } >> + >> + if (rate > cur_rate) >> + break; >> + >> + } >> + >> + return best_rate; >> +} >> + >> +static int clk_programmable_set_parent(struct clk_hw *hw, u8 index) >> +{ >> + struct clk_programmable *prog = to_clk_programmable(hw); >> + const struct clk_programmable_layout *layout = prog->layout; >> + if (index > layout->css_mask) { >> + if (index == 4 && layout->have_slck_mck) { > > define "4" > >> + prog->css = 0; >> + prog->slckmck = 1; >> + return 0; >> + } else > > Style: add the "{" > >> + return -EINVAL; > > and "}" > >> + } >> + >> + prog->css = index; >> + return 0; >> +} >> + >> +static u8 clk_programmable_get_parent(struct clk_hw *hw) >> +{ >> + u32 tmp; >> + u8 ret; >> + struct clk_programmable *prog = to_clk_programmable(hw); >> + struct at91_pmc *pmc = prog->pmc; >> + const struct clk_programmable_layout *layout = prog->layout; >> + >> + tmp = pmc_read(pmc, AT91_PMC_PCKR(prog->id)); >> + prog->css = tmp & layout->css_mask; >> + ret = prog->css; >> + if (layout->have_slck_mck) { >> + prog->slckmck = !!(tmp & (1 << 8)); > > Ditto > >> + if (prog->slckmck && !ret) >> + ret = 4; > > Ditto > >> + } >> + >> + return ret; >> +} >> + >> +static int clk_programmable_set_rate(struct clk_hw *hw, unsigned long rate, >> + unsigned long parent_rate) >> +{ >> + struct clk_programmable *prog = to_clk_programmable(hw); >> + unsigned long best_rate = parent_rate; >> + unsigned long best_diff; >> + unsigned long new_diff; >> + unsigned long cur_rate; >> + int shift = 0; >> + >> + if (rate > parent_rate) >> + return parent_rate; >> + else >> + best_diff = parent_rate - rate; >> + >> + if (!best_diff) { >> + prog->pres = shift; >> + return 0; >> + } >> + >> + for (shift = 1; shift < 7; shift++) { > > Ditto > >> + cur_rate = parent_rate >> shift; >> + >> + if (cur_rate > rate) >> + new_diff = cur_rate - rate; >> + else >> + new_diff = rate - cur_rate; >> + >> + if (!new_diff) >> + break; >> + >> + if (new_diff < best_diff) { >> + best_diff = new_diff; >> + best_rate = cur_rate; >> + } >> + >> + if (rate > cur_rate) >> + break; >> + >> + } >> + >> + prog->pres = shift; >> + return 0; >> +} >> + >> +static const struct clk_ops programmable_ops = { >> + .prepare = clk_programmable_prepare, >> + .is_prepared = clk_programmable_is_ready, >> + .recalc_rate = clk_programmable_recalc_rate, >> + .round_rate = clk_programmable_round_rate, >> + .get_parent = clk_programmable_get_parent, >> + .set_parent = clk_programmable_set_parent, >> + .set_rate = clk_programmable_set_rate, >> +}; >> + >> +static struct clk * __init >> +at91_clk_register_programmable(struct at91_pmc *pmc, unsigned int irq, >> + const char *name, const char **parent_names, >> + u8 num_parents, u8 id, >> + const struct clk_programmable_layout *layout) >> +{ >> + int ret; >> + struct clk_programmable *prog; >> + struct clk *clk = NULL; >> + struct clk_init_data init; >> + char irq_name[11]; >> + >> + id &= 7; > > Ditto > >> + >> + prog = kzalloc(sizeof(*prog), GFP_KERNEL); >> + if (!prog) >> + return ERR_PTR(-ENOMEM); >> + >> + init.name = name; >> + init.ops = &programmable_ops; >> + init.parent_names = parent_names; >> + init.num_parents = num_parents; >> + init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE; >> + >> + prog->id = id; >> + prog->layout = layout; >> + prog->hw.init = &init; >> + prog->pmc = pmc; >> + prog->irq = irq; >> + init_waitqueue_head(&prog->wait); >> + irq_set_status_flags(prog->irq, IRQ_NOAUTOEN); >> + snprintf(irq_name, sizeof(irq_name), "clk-prog%d", id); >> + ret = request_irq(prog->irq, clk_programmable_irq_handler, >> + IRQF_TRIGGER_HIGH, irq_name, prog); >> + if (ret) >> + return ERR_PTR(ret); >> + >> + clk = clk_register(NULL, &prog->hw); >> + > > ^^ > >> + if (IS_ERR(clk)) >> + kfree(prog); >> + >> + return clk; >> +} >> + >> +static const struct clk_programmable_layout at91rm9200_programmable_layout = { >> + .pres_shift = 2, >> + .css_mask = 0x3, >> + .have_slck_mck = 0, >> +}; >> + >> +static const struct clk_programmable_layout at91sam9g45_programmable_layout = { >> + .pres_shift = 2, >> + .css_mask = 0x3, >> + .have_slck_mck = 1, >> +}; >> + >> +static const struct clk_programmable_layout at91sam9x5_programmable_layout = { >> + .pres_shift = 4, >> + .css_mask = 0x7, >> + .have_slck_mck = 0, >> +}; >> + >> +struct clk_prog_data { >> + struct clk **clks; >> + u8 *ids; >> + unsigned int clk_num; >> +}; >> + >> +static struct clk * __init >> +of_clk_src_periph_get(struct of_phandle_args *clkspec, void *data) >> +{ >> + struct clk_prog_data *clk_data = data; >> + unsigned int id = clkspec->args[0]; >> + int i; >> + >> + if (id >= PROG_MAX) >> + goto err; >> + >> + for (i = 0; i < clk_data->clk_num; i++) { >> + if (clk_data->ids[i] == id) >> + return clk_data->clks[i]; >> + } >> + >> +err: >> + pr_err("%s: invalid clock id %d\n", __func__, id); >> + return ERR_PTR(-EINVAL); >> +} >> + >> +static void __init >> +of_at91_clk_prog_setup(struct device_node *np, struct at91_pmc *pmc, >> + const struct clk_programmable_layout *layout) >> +{ >> + int num; >> + u32 id; >> + int i; >> + unsigned int irq; >> + struct clk *clk; >> + int num_parents; >> + u8 *ids; >> + struct clk **clks; >> + struct clk_prog_data *clktab; >> + const char *parent_names[PROG_SOURCE_MAX]; >> + const char *name; >> + struct device_node *progclknp; >> + >> + num_parents = of_count_phandle_with_args(np, "clocks", "#clock-cells"); >> + if (num_parents <= 0 || num_parents > PROG_SOURCE_MAX) >> + return; >> + >> + for (i = 0; i < num_parents; ++i) { >> + parent_names[i] = of_clk_get_parent_name(np, i); >> + if (!parent_names[i]) >> + return; >> + } >> + >> + num = of_get_child_count(np); >> + if (!num || num > PROG_MAX) >> + return; >> + >> + clktab = kzalloc(sizeof(*clktab), GFP_KERNEL); >> + if (!clktab) >> + return; >> + >> + ids = kzalloc(num * sizeof(*ids), GFP_KERNEL); >> + if (!ids) >> + goto out_free_clktab; >> + >> + clks = kzalloc(num * sizeof(*clks), GFP_KERNEL); >> + if (!clks) >> + goto out_free_ids; >> + >> + i = 0; >> + for_each_child_of_node(np, progclknp) { >> + name = progclknp->name; >> + >> + if (of_property_read_u32(progclknp, "atmel,clk-id", &id)) >> + goto out_free_clks; >> + if (id >= PROG_MAX) >> + goto out_free_clks; >> + >> + irq = irq_of_parse_and_map(np, 0); >> + if (!irq) >> + goto out_free_clks; >> + >> + clk = at91_clk_register_programmable(pmc, irq, name, >> + parent_names, num_parents, >> + id, layout); >> + if (IS_ERR(clk)) >> + goto out_free_clks; >> + >> + clks[i] = clk; >> + ids[i++] = id; >> + } >> + >> + clktab->clk_num = num; >> + clktab->clks = clks; >> + clktab->ids = ids; >> + of_clk_add_provider(np, of_clk_src_periph_get, clktab); >> + return; >> + >> +out_free_clks: >> + kfree(clks); >> +out_free_ids: >> + kfree(ids); >> +out_free_clktab: >> + kfree(clktab); >> +} >> + >> + >> +void __init of_at91rm9200_clk_prog_setup(struct device_node *np, >> + struct at91_pmc *pmc) >> +{ >> + of_at91_clk_prog_setup(np, pmc, &at91rm9200_programmable_layout); >> +} >> + >> +void __init of_at91sam9g45_clk_prog_setup(struct device_node *np, >> + struct at91_pmc *pmc) >> +{ >> + of_at91_clk_prog_setup(np, pmc, &at91sam9g45_programmable_layout); >> +} >> + >> +void __init of_at91sam9x5_clk_prog_setup(struct device_node *np, >> + struct at91_pmc *pmc) >> +{ >> + of_at91_clk_prog_setup(np, pmc, &at91sam9x5_programmable_layout); >> +} >> diff --git a/drivers/clk/at91/pmc.c b/drivers/clk/at91/pmc.c >> index 1a56f1c..66a627d 100644 >> --- a/drivers/clk/at91/pmc.c >> +++ b/drivers/clk/at91/pmc.c >> @@ -265,6 +265,21 @@ static const struct of_device_id pmc_clk_ids[] __initdata = { >> .compatible = "atmel,at91sam9x5-clk-peripheral", >> .data = of_at91sam9x5_clk_periph_setup, >> }, >> + /* Programmable clocks */ >> +#if defined(CONFIG_AT91_PROGRAMMABLE_CLOCKS) >> + { >> + .compatible = "atmel,at91rm9200-clk-programmable", >> + .data = of_at91rm9200_clk_prog_setup, >> + }, >> + { >> + .compatible = "atmel,at91sam9g45-clk-programmable", >> + .data = of_at91sam9g45_clk_prog_setup, >> + }, >> + { >> + .compatible = "atmel,at91sam9x5-clk-programmable", >> + .data = of_at91sam9x5_clk_prog_setup, >> + }, >> +#endif >> { /*sentinel*/ } >> }; >> >> diff --git a/drivers/clk/at91/pmc.h b/drivers/clk/at91/pmc.h >> index 08c30fb..5f20dc1 100644 >> --- a/drivers/clk/at91/pmc.h >> +++ b/drivers/clk/at91/pmc.h >> @@ -82,4 +82,13 @@ extern void __init of_at91rm9200_clk_periph_setup(struct device_node *np, >> extern void __init of_at91sam9x5_clk_periph_setup(struct device_node *np, >> struct at91_pmc *pmc); >> >> +#if defined(CONFIG_AT91_PROGRAMMABLE_CLOCKS) >> +extern void __init of_at91rm9200_clk_prog_setup(struct device_node *np, >> + struct at91_pmc *pmc); >> +extern void __init of_at91sam9g45_clk_prog_setup(struct device_node *np, >> + struct at91_pmc *pmc); >> +extern void __init of_at91sam9x5_clk_prog_setup(struct device_node *np, >> + struct at91_pmc *pmc); >> +#endif >> + >> #endif /* __PMC_H_ */ >> > > -- Nicolas Ferre -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html