From patchwork Mon Oct 31 11:56:11 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tony Lindgren X-Patchwork-Id: 621040 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CA789FA3740 for ; Mon, 31 Oct 2022 11:56:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230265AbiJaL4a (ORCPT ); Mon, 31 Oct 2022 07:56:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55414 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231174AbiJaL41 (ORCPT ); Mon, 31 Oct 2022 07:56:27 -0400 Received: from muru.com (muru.com [72.249.23.125]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 34635EE18; Mon, 31 Oct 2022 04:56:26 -0700 (PDT) Received: from hillo.muru.com (localhost [127.0.0.1]) by muru.com (Postfix) with ESMTP id EE3818218; Mon, 31 Oct 2022 11:46:54 +0000 (UTC) From: Tony Lindgren To: Daniel Lezcano , Thomas Gleixner Cc: Georgi Vlaev , Grygorii Strashko , Keerthy , Ladislav Michl , Nishanth Menon , Suman Anna , Vignesh Raghavendra , linux-kernel@vger.kernel.org, linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [RFC PATCH 1/3] clocksource/drivers/timer-ti-dm: Add lock for register access Date: Mon, 31 Oct 2022 13:56:11 +0200 Message-Id: <20221031115613.56229-2-tony@atomide.com> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20221031115613.56229-1-tony@atomide.com> References: <20221031115613.56229-1-tony@atomide.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org We currently have no locking for timer control register and we assume that the consumer device using struct omap_dm_timer_ops takes care of locking for the timer. In order to prepare for adding irchip and clock provider support to start removing the struct omap_dm_timer_ops custom API, let's add timer->lock and use it for the timer control register. This is needed to protect the control register access between the different kernel frameworks. Not-Yet-Signed-off-by: Tony Lindgren --- drivers/clocksource/timer-ti-dm.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/drivers/clocksource/timer-ti-dm.c b/drivers/clocksource/timer-ti-dm.c --- a/drivers/clocksource/timer-ti-dm.c +++ b/drivers/clocksource/timer-ti-dm.c @@ -121,6 +121,7 @@ struct dmtimer { int id; int irq; struct clk *fclk; + spinlock_t lock; /* For shared register access */ void __iomem *io_base; int irq_stat; /* TISR/IRQSTATUS interrupt status */ @@ -633,6 +634,7 @@ static struct omap_dm_timer *omap_dm_timer_request_by_node(struct device_node *n static int omap_dm_timer_free(struct omap_dm_timer *cookie) { struct dmtimer *timer; + unsigned long flags; struct device *dev; int rc; @@ -649,7 +651,9 @@ static int omap_dm_timer_free(struct omap_dm_timer *cookie) return rc; /* Clear timer configuration */ + spin_lock_irqsave(&timer->lock, flags); dmtimer_write(timer, OMAP_TIMER_CTRL_REG, 0); + spin_unlock_irqrestore(&timer->lock, flags); pm_runtime_put_sync(dev); @@ -728,6 +732,7 @@ __u32 omap_dm_timer_modify_idlect_mask(__u32 inputmask) static int omap_dm_timer_start(struct omap_dm_timer *cookie) { struct dmtimer *timer; + unsigned long flags; struct device *dev; int rc; u32 l; @@ -742,11 +747,13 @@ static int omap_dm_timer_start(struct omap_dm_timer *cookie) if (rc) return rc; + spin_lock_irqsave(&timer->lock, flags); l = dmtimer_read(timer, OMAP_TIMER_CTRL_REG); if (!(l & OMAP_TIMER_CTRL_ST)) { l |= OMAP_TIMER_CTRL_ST; dmtimer_write(timer, OMAP_TIMER_CTRL_REG, l); } + spin_unlock_irqrestore(&timer->lock, flags); return 0; } @@ -754,6 +761,7 @@ static int omap_dm_timer_start(struct omap_dm_timer *cookie) static int omap_dm_timer_stop(struct omap_dm_timer *cookie) { struct dmtimer *timer; + unsigned long flags; struct device *dev; unsigned long rate = 0; @@ -766,7 +774,9 @@ static int omap_dm_timer_stop(struct omap_dm_timer *cookie) if (!timer->omap1) rate = clk_get_rate(timer->fclk); + spin_lock_irqsave(&timer->lock, flags); __omap_dm_timer_stop(timer, rate); + spin_unlock_irqrestore(&timer->lock, flags); pm_runtime_put_sync(dev); @@ -800,6 +810,7 @@ static int omap_dm_timer_set_match(struct omap_dm_timer *cookie, int enable, unsigned int match) { struct dmtimer *timer; + unsigned long flags; struct device *dev; int rc; u32 l; @@ -813,6 +824,7 @@ static int omap_dm_timer_set_match(struct omap_dm_timer *cookie, int enable, if (rc) return rc; + spin_lock_irqsave(&timer->lock, flags); l = dmtimer_read(timer, OMAP_TIMER_CTRL_REG); if (enable) l |= OMAP_TIMER_CTRL_CE; @@ -820,6 +832,7 @@ static int omap_dm_timer_set_match(struct omap_dm_timer *cookie, int enable, l &= ~OMAP_TIMER_CTRL_CE; dmtimer_write(timer, OMAP_TIMER_MATCH_REG, match); dmtimer_write(timer, OMAP_TIMER_CTRL_REG, l); + spin_unlock_irqrestore(&timer->lock, flags); pm_runtime_put_sync(dev); @@ -830,6 +843,7 @@ static int omap_dm_timer_set_pwm(struct omap_dm_timer *cookie, int def_on, int toggle, int trigger, int autoreload) { struct dmtimer *timer; + unsigned long flags; struct device *dev; int rc; u32 l; @@ -843,6 +857,7 @@ static int omap_dm_timer_set_pwm(struct omap_dm_timer *cookie, int def_on, if (rc) return rc; + spin_lock_irqsave(&timer->lock, flags); l = dmtimer_read(timer, OMAP_TIMER_CTRL_REG); l &= ~(OMAP_TIMER_CTRL_GPOCFG | OMAP_TIMER_CTRL_SCPWM | OMAP_TIMER_CTRL_PT | (0x03 << 10) | OMAP_TIMER_CTRL_AR); @@ -854,6 +869,7 @@ static int omap_dm_timer_set_pwm(struct omap_dm_timer *cookie, int def_on, if (autoreload) l |= OMAP_TIMER_CTRL_AR; dmtimer_write(timer, OMAP_TIMER_CTRL_REG, l); + spin_unlock_irqrestore(&timer->lock, flags); pm_runtime_put_sync(dev); @@ -887,6 +903,7 @@ static int omap_dm_timer_set_prescaler(struct omap_dm_timer *cookie, int prescaler) { struct dmtimer *timer; + unsigned long flags; struct device *dev; int rc; u32 l; @@ -900,6 +917,7 @@ static int omap_dm_timer_set_prescaler(struct omap_dm_timer *cookie, if (rc) return rc; + spin_lock_irqsave(&timer->lock, flags); l = dmtimer_read(timer, OMAP_TIMER_CTRL_REG); l &= ~(OMAP_TIMER_CTRL_PRE | (0x07 << 2)); if (prescaler >= 0) { @@ -907,6 +925,7 @@ static int omap_dm_timer_set_prescaler(struct omap_dm_timer *cookie, l |= prescaler << 2; } dmtimer_write(timer, OMAP_TIMER_CTRL_REG, l); + spin_unlock_irqrestore(&timer->lock, flags); pm_runtime_put_sync(dev); @@ -1093,6 +1112,8 @@ static int omap_dm_timer_probe(struct platform_device *pdev) if (!timer) return -ENOMEM; + spin_lock_init(&timer->lock); + timer->irq = platform_get_irq(pdev, 0); if (timer->irq < 0) return timer->irq; From patchwork Mon Oct 31 11:56:12 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tony Lindgren X-Patchwork-Id: 620386 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5AA46C38A02 for ; Mon, 31 Oct 2022 11:56:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230327AbiJaL4c (ORCPT ); Mon, 31 Oct 2022 07:56:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55476 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230462AbiJaL4a (ORCPT ); Mon, 31 Oct 2022 07:56:30 -0400 Received: from muru.com (muru.com [72.249.23.125]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id E0771EE06; Mon, 31 Oct 2022 04:56:29 -0700 (PDT) Received: from hillo.muru.com (localhost [127.0.0.1]) by muru.com (Postfix) with ESMTP id 9195780CD; Mon, 31 Oct 2022 11:46:58 +0000 (UTC) From: Tony Lindgren To: Daniel Lezcano , Thomas Gleixner Cc: Georgi Vlaev , Grygorii Strashko , Keerthy , Ladislav Michl , Nishanth Menon , Suman Anna , Vignesh Raghavendra , linux-kernel@vger.kernel.org, linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [RFC PATCH 2/3] clocksource/drivers/timer-ti-dm: Implement chained irq Date: Mon, 31 Oct 2022 13:56:12 +0200 Message-Id: <20221031115613.56229-3-tony@atomide.com> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20221031115613.56229-1-tony@atomide.com> References: <20221031115613.56229-1-tony@atomide.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org The timer has input capture support that can be used for PWM capture. And some drivers, like remoteproc, already use hardware timers directly as described in commit e28edc571925 ("remoteproc/omap: Request a timer(s) for remoteproc usage"). We can simplify the the use of some hardware timer features for PWM and remoteproc with chained irq. This allows us to eventually deprecate the following functions exposed by struct omap_dm_timer_ops: get_irq() set_int_enable() set_int_disable(), read_status() write_status() The functions above can be dropped after omap_remoteproc has been updated to request a timer irq. For PWM, set_match() is still needed for input capture. Not-Yet-Signed-off-by: Tony Lindgren --- drivers/clocksource/timer-ti-dm.c | 255 +++++++++++++++++++++++++++++- drivers/pwm/pwm-omap-dmtimer.c | 1 + 2 files changed, 248 insertions(+), 8 deletions(-) diff --git a/drivers/clocksource/timer-ti-dm.c b/drivers/clocksource/timer-ti-dm.c --- a/drivers/clocksource/timer-ti-dm.c +++ b/drivers/clocksource/timer-ti-dm.c @@ -22,6 +22,8 @@ #include #include #include +#include +#include #include #include #include @@ -29,6 +31,7 @@ #include #include #include +#include #include #include @@ -46,6 +49,7 @@ /* posted mode types */ #define OMAP_TIMER_NONPOSTED 0x00 #define OMAP_TIMER_POSTED 0x01 +#define OMAP_DM_TIMER_NR_IRQS 3 /* Capture, overflow, match */ /* register offsets with the write pending bit encoded */ #define WPSHIFT 16 @@ -142,6 +146,8 @@ struct dmtimer { struct platform_device *pdev; struct list_head node; struct notifier_block nb; + struct irq_chip chip; + struct irq_domain *domain; }; static u32 omap_reserved_systimers; @@ -286,6 +292,232 @@ static inline void __omap_dm_timer_int_enable(struct dmtimer *timer, dmtimer_write(timer, OMAP_TIMER_WAKEUP_EN_REG, value); } +static inline void __omap_dm_timer_int_disable(struct dmtimer *timer, + unsigned int mask) +{ + u32 l = mask; + + if (timer->revision == 1) + l = dmtimer_read(timer, timer->irq_ena) & ~mask; + + dmtimer_write(timer, timer->irq_dis, l); + l = dmtimer_read(timer, OMAP_TIMER_WAKEUP_EN_REG) & ~mask; + dmtimer_write(timer, OMAP_TIMER_WAKEUP_EN_REG, l); +} + +/* + * Chained interrupt support for input pin event capture for PWM. + */ +static void dmtimer_chain_handler(struct irq_desc *desc) +{ + struct dmtimer *timer = irq_desc_get_handler_data(desc); + struct irq_chip *chip; + unsigned int bit; + unsigned long l; + + chip = irq_desc_get_chip(desc); + chained_irq_enter(chip, desc); + l = dmtimer_read(timer, timer->irq_stat); + + for_each_set_bit(bit, &l, OMAP_DM_TIMER_NR_IRQS) + generic_handle_domain_irq(timer->domain, bit); + + chained_irq_exit(chip, desc); +} + +static struct lock_class_key dmtimer_lock_class; +static struct lock_class_key dmtimer_request_class; + +static int dmtimer_irqdomain_map(struct irq_domain *d, unsigned int irq, + irq_hw_number_t hwirq) +{ + struct dmtimer *timer = d->host_data; + + irq_set_chip_data(irq, timer); + irq_set_chip_and_handler(irq, &timer->chip, + handle_level_irq); + irq_set_lockdep_class(irq, &dmtimer_lock_class, + &dmtimer_request_class); + irq_set_noprobe(irq); + + return 0; +} + +static const struct irq_domain_ops dmtimer_irqdomain_ops = { + .map = dmtimer_irqdomain_map, + .xlate = irq_domain_xlate_twocell, +}; + +static void dmtimer_irq_mask(struct irq_data *d); +static void dmtimer_irq_unmask(struct irq_data *d); + +static unsigned int dmtimer_irq_startup(struct irq_data *d) +{ + struct dmtimer *timer = irq_data_get_irq_chip_data(d); + unsigned long flags; + u32 l, val; + + switch (BIT(d->hwirq)) { + case OMAP_TIMER_INT_CAPTURE: + val = OMAP_TIMER_CTRL_GPOCFG; + break; + case OMAP_TIMER_INT_OVERFLOW: + goto unmask; + case OMAP_TIMER_INT_MATCH: + val = OMAP_TIMER_CTRL_CE; + break; + default: + return 0; + } + + spin_lock_irqsave(&timer->lock, flags); + l = dmtimer_read(timer, OMAP_TIMER_CTRL_REG); + l |= val; + dmtimer_write(timer, OMAP_TIMER_CTRL_REG, l); + spin_unlock_irqrestore(&timer->lock, flags); + +unmask: + dmtimer_irq_unmask(d); + + return 0; +} + +static void dmtimer_irq_shutdown(struct irq_data *d) +{ + struct dmtimer *timer = irq_data_get_irq_chip_data(d); + unsigned long flags; + u32 l, val; + + switch (BIT(d->hwirq)) { + case OMAP_TIMER_INT_CAPTURE: + val = OMAP_TIMER_CTRL_GPOCFG; + break; + case OMAP_TIMER_INT_OVERFLOW: + goto mask; + case OMAP_TIMER_INT_MATCH: + val = OMAP_TIMER_CTRL_CE; + break; + default: + return; + } + + spin_lock_irqsave(&timer->lock, flags); + l = dmtimer_read(timer, OMAP_TIMER_CTRL_REG); + l &= ~val; + dmtimer_write(timer, OMAP_TIMER_CTRL_REG, l); + spin_unlock_irqrestore(&timer->lock, flags); + +mask: + dmtimer_irq_mask(d); +} + +static void dmtimer_irq_mask(struct irq_data *d) +{ + struct dmtimer *timer = irq_data_get_irq_chip_data(d); + u32 mask = BIT(d->hwirq); + + __omap_dm_timer_int_disable(timer, mask); +} + +static void dmtimer_irq_unmask(struct irq_data *d) +{ + struct dmtimer *timer = irq_data_get_irq_chip_data(d); + u32 mask = BIT(d->hwirq); + + __omap_dm_timer_int_enable(timer, mask); +} + +static void dmtimer_irq_ack(struct irq_data *d) +{ + struct dmtimer *timer = irq_data_get_irq_chip_data(d); + + dmtimer_write(timer, timer->irq_stat, BIT(d->hwirq)); +} + +static void dmtimer_irq_mask_ack(struct irq_data *d) +{ + struct dmtimer *timer = irq_data_get_irq_chip_data(d); + u32 mask = BIT(d->hwirq); + + __omap_dm_timer_int_disable(timer, mask); + dmtimer_write(timer, timer->irq_stat, mask); +} + +static int dmtimer_irq_set_type(struct irq_data *d, unsigned int type) +{ + struct dmtimer *timer = irq_data_get_irq_chip_data(d); + unsigned long flags; + u32 l; + + /* TIMER_TCLR register TCM bits match IRQ_TYPE values for edge */ + switch (type) { + case IRQ_TYPE_NONE: + case IRQ_TYPE_EDGE_RISING: + case IRQ_TYPE_EDGE_FALLING: + case IRQ_TYPE_EDGE_BOTH: + break; + default: + return -EINVAL; + } + + /* Configure TCLR register TCM bits */ + spin_lock_irqsave(&timer->lock, flags); + l = dmtimer_read(timer, OMAP_TIMER_CTRL_REG); + l &= ~(3 << 8); + l |= (type << 8); + dmtimer_write(timer, OMAP_TIMER_CTRL_REG, l); + spin_unlock_irqrestore(&timer->lock, flags); + + return 0; +} + +static int dmtimer_irq_set_wake(struct irq_data *d, unsigned int state) +{ + if (state) + dmtimer_irq_unmask(d); + else + dmtimer_irq_mask(d); + + return 0; +} + +static int dmtimer_register_irqchip(struct dmtimer *timer) +{ + struct device *dev = &timer->pdev->dev; + struct device_node *np = dev->of_node; + + /* Can be removed if omap1 starts using timer-ti-dm-systimer */ + if (timer->omap1) + return 0; + + timer->chip.name = dev->driver->name; + timer->chip.irq_startup = dmtimer_irq_startup; + timer->chip.irq_shutdown = dmtimer_irq_shutdown; + timer->chip.irq_mask = dmtimer_irq_mask; + timer->chip.irq_unmask = dmtimer_irq_unmask; + timer->chip.irq_ack = dmtimer_irq_ack; + timer->chip.irq_mask_ack = dmtimer_irq_mask_ack; + timer->chip.irq_set_type = dmtimer_irq_set_type; + timer->chip.irq_set_wake = dmtimer_irq_set_wake; + + irq_set_chained_handler_and_data(timer->irq, + dmtimer_chain_handler, + timer); + + timer->domain = irq_domain_add_simple(np, OMAP_DM_TIMER_NR_IRQS, 0, + &dmtimer_irqdomain_ops, + timer); + if (!timer->domain) { + irq_set_chained_handler(timer->irq, NULL); + return -EINVAL; + } + + /* Initialize dev for runtime PM, see irq_chip_pm_get() */ + timer->domain->dev = dev; + + return 0; +} + static inline unsigned int __omap_dm_timer_read_counter(struct dmtimer *timer) { @@ -966,7 +1198,6 @@ static int omap_dm_timer_set_int_disable(struct omap_dm_timer *cookie, u32 mask) { struct dmtimer *timer; struct device *dev; - u32 l = mask; int rc; timer = to_dmtimer(cookie); @@ -978,12 +1209,7 @@ static int omap_dm_timer_set_int_disable(struct omap_dm_timer *cookie, u32 mask) if (rc) return rc; - if (timer->revision == 1) - l = dmtimer_read(timer, timer->irq_ena) & ~mask; - - dmtimer_write(timer, timer->irq_dis, l); - l = dmtimer_read(timer, OMAP_TIMER_WAKEUP_EN_REG) & ~mask; - dmtimer_write(timer, OMAP_TIMER_WAKEUP_EN_REG, l); + __omap_dm_timer_int_disable(timer, mask); pm_runtime_put_sync(dev); @@ -1173,6 +1399,12 @@ static int omap_dm_timer_probe(struct platform_device *pdev) /* Clear timer configuration */ dmtimer_write(timer, OMAP_TIMER_CTRL_REG, 0); + ret = dmtimer_register_irqchip(timer); + if (ret) { + dev_err(dev, "irqchip register failed: %i\n", ret); + goto err_put; + } + pm_runtime_put(dev); } @@ -1185,6 +1417,8 @@ static int omap_dm_timer_probe(struct platform_device *pdev) return 0; +err_put: + pm_runtime_put(dev); err_disable: pm_runtime_disable(dev); return ret; @@ -1205,15 +1439,20 @@ static int omap_dm_timer_remove(struct platform_device *pdev) int ret = -EINVAL; spin_lock_irqsave(&dm_timer_lock, flags); - list_for_each_entry(timer, &omap_timer_list, node) + list_for_each_entry(timer, &omap_timer_list, node) { if (!strcmp(dev_name(&timer->pdev->dev), dev_name(&pdev->dev))) { + if (timer->domain) { + irq_domain_remove(timer->domain); + irq_set_chained_handler(timer->irq, NULL); + } if (!(timer->capability & OMAP_TIMER_ALWON)) cpu_pm_unregister_notifier(&timer->nb); list_del(&timer->node); ret = 0; break; } + } spin_unlock_irqrestore(&dm_timer_lock, flags); pm_runtime_disable(&pdev->dev); diff --git a/drivers/pwm/pwm-omap-dmtimer.c b/drivers/pwm/pwm-omap-dmtimer.c --- a/drivers/pwm/pwm-omap-dmtimer.c +++ b/drivers/pwm/pwm-omap-dmtimer.c @@ -35,6 +35,7 @@ #include #include +#include #include #include #include From patchwork Mon Oct 31 11:56:13 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tony Lindgren X-Patchwork-Id: 621039 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 90803C38A02 for ; Mon, 31 Oct 2022 11:56:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230525AbiJaL4h (ORCPT ); Mon, 31 Oct 2022 07:56:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55620 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231182AbiJaL4f (ORCPT ); Mon, 31 Oct 2022 07:56:35 -0400 Received: from muru.com (muru.com [72.249.23.125]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 587E6D85; Mon, 31 Oct 2022 04:56:33 -0700 (PDT) Received: from hillo.muru.com (localhost [127.0.0.1]) by muru.com (Postfix) with ESMTP id 338138218; Mon, 31 Oct 2022 11:47:02 +0000 (UTC) From: Tony Lindgren To: Daniel Lezcano , Thomas Gleixner Cc: Georgi Vlaev , Grygorii Strashko , Keerthy , Ladislav Michl , Nishanth Menon , Suman Anna , Vignesh Raghavendra , linux-kernel@vger.kernel.org, linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [RFC PATCH 3/3] clocksource/drivers/timer-ti-dm: Add clock provider support Date: Mon, 31 Oct 2022 13:56:13 +0200 Message-Id: <20221031115613.56229-4-tony@atomide.com> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20221031115613.56229-1-tony@atomide.com> References: <20221031115613.56229-1-tony@atomide.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org Kernel drivers can use some of the dedicated hardware timer features to provide a clock source on a timer output pin. Instead of exposing the timer features with struct omap_dm_timer_ops, let's add clock provider support. Also the PWM driver can be simplified with clk_set_duty_cycle() and clk_get_scaled_duty_cycle(). This allows us to eventually deprecate the following functions exposed by struct omap_dm_timer_ops: enable() disable() start() stop() get_fclk() set_source() Not-Yet-Signed-off-by: Tony Lindgren --- drivers/clocksource/timer-ti-dm.c | 315 +++++++++++++++++++++++++++++- include/clocksource/timer-ti-dm.h | 2 + 2 files changed, 309 insertions(+), 8 deletions(-) diff --git a/drivers/clocksource/timer-ti-dm.c b/drivers/clocksource/timer-ti-dm.c --- a/drivers/clocksource/timer-ti-dm.c +++ b/drivers/clocksource/timer-ti-dm.c @@ -99,6 +99,16 @@ #define OMAP_TIMER_TICK_INT_MASK_COUNT_REG \ (_OMAP_TIMER_TICK_INT_MASK_COUNT_OFFSET | (WP_TOWR << WPSHIFT)) +/* + * Timer counts up with a maximum theoretical value of 0xffffffff meaning one + * clock cycle. In counter mode, the timer is however limited to a maximum value + * of 0xfffffffe for two clock cycles. And in PWM mode, the timer is limited to + * a maximum value of 0xfffffffd for three clock cycles. DMTIMER_CYCLES is only + * used for clock cycle calculations, and does not consider the hardware limits. + * The related timer functions check for the minimum allowed clock cycles. + */ +#define DMTIMER_CYCLES(x) (0xffffffff - (x) + 1) + struct timer_regs { u32 ocp_cfg; u32 tidr; @@ -143,11 +153,14 @@ struct dmtimer { int revision; u32 capability; u32 errata; + u32 load_val; + u32 match_val; struct platform_device *pdev; struct list_head node; struct notifier_block nb; struct irq_chip chip; struct irq_domain *domain; + struct clk_hw hw; }; static u32 omap_reserved_systimers; @@ -261,6 +274,19 @@ static inline void __omap_dm_timer_enable_posted(struct dmtimer *timer) timer->posted = OMAP_TIMER_POSTED; } +static inline void __omap_dm_timer_start(struct dmtimer *timer, bool autoreload) +{ + u32 l, mask; + + mask = OMAP_TIMER_CTRL_ST; + if (autoreload) + mask |= OMAP_TIMER_CTRL_AR; + + l = dmtimer_read(timer, OMAP_TIMER_CTRL_REG); + if ((l & mask) != mask) + dmtimer_write(timer, OMAP_TIMER_CTRL_REG, l | mask); +} + static inline void __omap_dm_timer_stop(struct dmtimer *timer, unsigned long rate) { @@ -610,6 +636,275 @@ static int omap_dm_timer_reset(struct dmtimer *timer) return 0; } +/* Clock provider support */ +#if defined(CONFIG_COMMON_CLK) + +#define hw_to_dmtimer(x) container_of(x, struct dmtimer, hw) + +static int dmtimer_clk_prepare(struct clk_hw *hw) +{ + struct dmtimer *timer = hw_to_dmtimer(hw); + struct device *dev = &timer->pdev->dev; + int rc; + u32 l; + + rc = pm_runtime_resume_and_get(dev); + if (rc) + return rc; + + /* Clear output and set toggle modulation */ + l = dmtimer_read(timer, OMAP_TIMER_CTRL_REG); + l &= ~OMAP_TIMER_CTRL_GPOCFG; + l |= OMAP_TIMER_CTRL_PT; + l &= ~(OMAP_TIMER_CTRL_TRIGGER_MASK << OMAP_TIMER_CTRL_TRIGGER_SHIFT); + l |= OMAP_TIMER_TRIGGER_OVERFLOW_AND_COMPARE << OMAP_TIMER_CTRL_TRIGGER_SHIFT; + dmtimer_write(timer, OMAP_TIMER_CTRL_REG, l); + + return rc; +} + +static void dmtimer_clk_unprepare(struct clk_hw *hw) +{ + struct dmtimer *timer = hw_to_dmtimer(hw); + struct device *dev = &timer->pdev->dev; + u32 l; + + /* Clear output and toggle modulation */ + l = dmtimer_read(timer, OMAP_TIMER_CTRL_REG); + l &= ~(OMAP_TIMER_CTRL_GPOCFG | OMAP_TIMER_CTRL_PT); + l &= ~(OMAP_TIMER_CTRL_TRIGGER_MASK << OMAP_TIMER_CTRL_TRIGGER_SHIFT); + dmtimer_write(timer, OMAP_TIMER_CTRL_REG, l); + + pm_runtime_put_sync(dev); +} + +static int dmtimer_clk_enable(struct clk_hw *hw) +{ + struct dmtimer *timer = hw_to_dmtimer(hw); + unsigned long flags; + + /* Configure immediate overflow to toggle PWM on first event, see TRM */ + spin_lock_irqsave(&timer->lock, flags); + dmtimer_write(timer, OMAP_TIMER_COUNTER_REG, DMTIMER_CYCLES(1)); + __omap_dm_timer_start(timer, true); + spin_unlock_irqrestore(&timer->lock, flags); + + return 0; +} + +static void dmtimer_clk_disable(struct clk_hw *hw) +{ + struct dmtimer *timer = hw_to_dmtimer(hw); + unsigned long rate = 0; + + if (!timer->omap1) + rate = clk_get_rate(timer->fclk); + + __omap_dm_timer_stop(timer, rate); +} + +static int dmtimer_clk_is_enabled(struct clk_hw *hw) +{ + struct dmtimer *timer = hw_to_dmtimer(hw); + + return atomic_read(&timer->enabled); +} + +static int dmtimer_get_prescale(struct dmtimer *timer) +{ + u32 l; + + l = dmtimer_read(timer, OMAP_TIMER_CTRL_REG); + if (!(l & OMAP_TIMER_CTRL_PRE)) + return 1; + + return 2 << ((l >> OMAP_TIMER_CTRL_PTV_SHIFT) & 7); +} + +static unsigned long dmtimer_clk_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct dmtimer *timer = hw_to_dmtimer(hw); + int prescale; + u32 loadval; + + prescale = dmtimer_get_prescale(timer); + loadval = dmtimer_read(timer, OMAP_TIMER_LOAD_REG); + + return parent_rate / prescale / DMTIMER_CYCLES(loadval); +} + +static long dmtimer_clk_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *parent_rate) +{ + unsigned int div; + + div = DIV_ROUND_CLOSEST(*parent_rate, rate); + + return *parent_rate / div; +} + +static int dmtimer_clk_get_duty_cycle(struct clk_hw *hw, + struct clk_duty *duty) +{ + struct dmtimer *timer = hw_to_dmtimer(hw); + u32 match, load; + + match = dmtimer_read(timer, OMAP_TIMER_MATCH_REG); + load = dmtimer_read(timer, OMAP_TIMER_LOAD_REG); + duty->num = match - load; + duty->den = DMTIMER_CYCLES(load); + + return 0; +} + +/* + * See am62 TRM "Table 12-312. Prescaler Clock Ratio Values" for PWM limits for + * the max load register value. + */ +static int dmtimer_clk_set_duty_cycle(struct clk_hw *hw, + struct clk_duty *duty) +{ + struct dmtimer *timer = hw_to_dmtimer(hw); + u32 cycles, match; + + if (!timer->load_val) { + dev_err(&timer->pdev->dev, "no rate configured for duty_cycle"); + return -EINVAL; + } + + cycles = DMTIMER_CYCLES(timer->load_val); + match = mult_frac(cycles, duty->num, duty->den); + timer->match_val = timer->load_val + match; + dmtimer_write(timer, OMAP_TIMER_MATCH_REG, timer->match_val); + + return 0; +} + +/* + * Note that setting the TCLR register prescaler value is not currently + * implemented, it can be added if needed with some clock sources. + */ +static int dmtimer_clk_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct dmtimer *timer = hw_to_dmtimer(hw); + struct device *dev = &timer->pdev->dev; + struct clk_duty duty; + unsigned int div; + int prescale, rc; + u32 cycles; + + if (rate > parent_rate) + return -EINVAL; + + prescale = dmtimer_get_prescale(timer); + div = parent_rate / prescale; + cycles = div / rate; + + /* + * TRM "Timer Pulse-Width Modulation" chapter says in PWM mode + * TIMER_TLDR load register must be limited to max 0xfffffffd + * limiting the minimum usable clock cycles to 3. + */ + if (cycles < 3) + return -EINVAL; + + timer->load_val = DMTIMER_CYCLES(cycles); + dmtimer_write(timer, OMAP_TIMER_LOAD_REG, timer->load_val); + + /* Configure 50% duty cycle by default */ + if (!timer->match_val) { + duty.num = div / 2; + duty.den = div; + + rc = dmtimer_clk_set_duty_cycle(hw, &duty); + if (rc) + dev_err(dev, "set_rate duty cycle failed: %i\n", rc); + } + + return rc; +} + +static int dmtimer_clk_get_phase(struct clk_hw *hw) +{ + struct dmtimer *timer = hw_to_dmtimer(hw); + u32 l = dmtimer_read(timer, OMAP_TIMER_CTRL_REG); + + return (l & OMAP_TIMER_CTRL_SCPWM) ? 180 : 0; +} + +static int dmtimer_clk_set_phase(struct clk_hw *hw, int degrees) +{ + struct dmtimer *timer = hw_to_dmtimer(hw); + u32 l = dmtimer_read(timer, OMAP_TIMER_CTRL_REG); + + l &= ~OMAP_TIMER_CTRL_SCPWM; + + switch (degrees) { + case 0: + break; + case 180: + l |= OMAP_TIMER_CTRL_SCPWM; + break; + default: + return -EINVAL; + } + + dmtimer_write(timer, OMAP_TIMER_CTRL_REG, l); + + return 0; +} + +static const struct clk_ops dmtimer_clk_ops = { + .prepare = dmtimer_clk_prepare, + .unprepare = dmtimer_clk_unprepare, + .enable = dmtimer_clk_enable, + .disable = dmtimer_clk_disable, + .is_enabled = dmtimer_clk_is_enabled, + .recalc_rate = dmtimer_clk_recalc_rate, + .round_rate = dmtimer_clk_round_rate, + .set_rate = dmtimer_clk_set_rate, + .get_phase = dmtimer_clk_get_phase, + .set_phase = dmtimer_clk_set_phase, + .get_duty_cycle = dmtimer_clk_get_duty_cycle, + .set_duty_cycle = dmtimer_clk_set_duty_cycle, +}; + +static int dmtimer_register_clock(struct dmtimer *timer) +{ + struct device *dev = &timer->pdev->dev; + struct device_node *np = dev->of_node; + struct clk_init_data init = { }; + struct clk_hw *hw; + const char *fck; + int ret; + + if (!np || !of_find_property(np, "#clock-cells", NULL)) + return 0; + + hw = &timer->hw; + init.name = dev_name(dev); + init.ops = &dmtimer_clk_ops; + init.flags = CLK_GET_RATE_NOCACHE; + init.num_parents = 1; + fck = __clk_get_name(timer->fclk); + init.parent_names = &fck; + hw->init = &init; + ret = devm_clk_hw_register(dev, hw); + if (ret) + return ret; + + return devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get, hw); +} + +#else +static inline int dmtimer_register_clock(struct dmtimer *timer) +{ + return 0; +} +#endif /* CONFIG_COMMON_CLK */ + /* * Functions exposed to PWM and remoteproc drivers via platform_data. * Do not use these in the driver, these will get deprecated and will @@ -885,6 +1180,7 @@ static int omap_dm_timer_free(struct omap_dm_timer *cookie) /* Clear timer configuration */ spin_lock_irqsave(&timer->lock, flags); dmtimer_write(timer, OMAP_TIMER_CTRL_REG, 0); + dmtimer_write(timer, OMAP_TIMER_LOAD_REG, timer->load_val); spin_unlock_irqrestore(&timer->lock, flags); pm_runtime_put_sync(dev); @@ -967,7 +1263,6 @@ static int omap_dm_timer_start(struct omap_dm_timer *cookie) unsigned long flags; struct device *dev; int rc; - u32 l; timer = to_dmtimer(cookie); if (unlikely(!timer)) @@ -980,11 +1275,7 @@ static int omap_dm_timer_start(struct omap_dm_timer *cookie) return rc; spin_lock_irqsave(&timer->lock, flags); - l = dmtimer_read(timer, OMAP_TIMER_CTRL_REG); - if (!(l & OMAP_TIMER_CTRL_ST)) { - l |= OMAP_TIMER_CTRL_ST; - dmtimer_write(timer, OMAP_TIMER_CTRL_REG, l); - } + __omap_dm_timer_start(timer, false); spin_unlock_irqrestore(&timer->lock, flags); return 0; @@ -1092,12 +1383,14 @@ static int omap_dm_timer_set_pwm(struct omap_dm_timer *cookie, int def_on, spin_lock_irqsave(&timer->lock, flags); l = dmtimer_read(timer, OMAP_TIMER_CTRL_REG); l &= ~(OMAP_TIMER_CTRL_GPOCFG | OMAP_TIMER_CTRL_SCPWM | - OMAP_TIMER_CTRL_PT | (0x03 << 10) | OMAP_TIMER_CTRL_AR); + OMAP_TIMER_CTRL_PT | + (OMAP_TIMER_CTRL_TRIGGER_MASK << OMAP_TIMER_CTRL_TRIGGER_SHIFT) | + OMAP_TIMER_CTRL_AR); if (def_on) l |= OMAP_TIMER_CTRL_SCPWM; if (toggle) l |= OMAP_TIMER_CTRL_PT; - l |= trigger << 10; + l |= trigger << OMAP_TIMER_CTRL_TRIGGER_SHIFT; if (autoreload) l |= OMAP_TIMER_CTRL_AR; dmtimer_write(timer, OMAP_TIMER_CTRL_REG, l); @@ -1399,6 +1692,12 @@ static int omap_dm_timer_probe(struct platform_device *pdev) /* Clear timer configuration */ dmtimer_write(timer, OMAP_TIMER_CTRL_REG, 0); + ret = dmtimer_register_clock(timer); + if (ret) { + dev_err(dev, "clock provider register failed: %i\n", ret); + goto err_put; + } + ret = dmtimer_register_irqchip(timer); if (ret) { dev_err(dev, "irqchip register failed: %i\n", ret); diff --git a/include/clocksource/timer-ti-dm.h b/include/clocksource/timer-ti-dm.h --- a/include/clocksource/timer-ti-dm.h +++ b/include/clocksource/timer-ti-dm.h @@ -98,6 +98,8 @@ u32 omap_dm_timer_modify_idlect_mask(u32 inputmask); #define OMAP_TIMER_CTRL_GPOCFG (1 << 14) #define OMAP_TIMER_CTRL_CAPTMODE (1 << 13) #define OMAP_TIMER_CTRL_PT (1 << 12) +#define OMAP_TIMER_CTRL_TRIGGER_SHIFT 10 +#define OMAP_TIMER_CTRL_TRIGGER_MASK 3 #define OMAP_TIMER_CTRL_TCM_LOWTOHIGH (0x1 << 8) #define OMAP_TIMER_CTRL_TCM_HIGHTOLOW (0x2 << 8) #define OMAP_TIMER_CTRL_TCM_BOTHEDGES (0x3 << 8)