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[PATCH 4.10 47/69] pwm: rockchip: State of PWM clock should synchronize with PWM enabled state

From Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Newsgroups linux.kernel
Subject [PATCH 4.10 47/69] pwm: rockchip: State of PWM clock should synchronize with PWM enabled state
Date 2017-04-19 17:30 +0200
Message-ID <txZIp-56L-83@gated-at.bofh.it> (permalink)
References <txYVX-4yJ-3@gated-at.bofh.it>
Organization linux.* mail to news gateway

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4.10-stable review patch.  If anyone has any objections, please let me know.

------------------

From: David Wu <david.wu@rock-chips.com>

commit a900152b5c29aea8134cc7a4c5db25552b3cd8f7 upstream.

If the PWM was not enabled at U-Boot loader, PWM could not work for
clock always disabled at PWM driver. The PWM clock is enabled at
beginning of pwm_apply(), but disabled at end of pwm_apply().

If the PWM was enabled at U-Boot loader, PWM clock is always enabled
unless closed by ATF. The pwm-backlight might turn off the power at
early suspend, should disable PWM clock for saving power consume.

It is important to provide opportunity to enable/disable clock at PWM
driver, the PWM consumer should ensure correct order to call PWM enable
and disable, and PWM driver ensure state of PWM clock synchronized with
PWM enabled state.

Fixes: 2bf1c98aa5a4 ("pwm: rockchip: Add support for atomic update")
Signed-off-by: David Wu <david.wu@rock-chips.com>
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/pwm/pwm-rockchip.c |   40 +++++++++++++++++++++++++++++++++-------
 1 file changed, 33 insertions(+), 7 deletions(-)

--- a/drivers/pwm/pwm-rockchip.c
+++ b/drivers/pwm/pwm-rockchip.c
@@ -191,6 +191,28 @@ static int rockchip_pwm_config(struct pw
 	return 0;
 }
 
+static int rockchip_pwm_enable(struct pwm_chip *chip,
+			 struct pwm_device *pwm,
+			 bool enable,
+			 enum pwm_polarity polarity)
+{
+	struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
+	int ret;
+
+	if (enable) {
+		ret = clk_enable(pc->clk);
+		if (ret)
+			return ret;
+	}
+
+	pc->data->set_enable(chip, pwm, enable, polarity);
+
+	if (!enable)
+		clk_disable(pc->clk);
+
+	return 0;
+}
+
 static int rockchip_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 			      struct pwm_state *state)
 {
@@ -207,22 +229,26 @@ static int rockchip_pwm_apply(struct pwm
 		return ret;
 
 	if (state->polarity != curstate.polarity && enabled) {
-		pc->data->set_enable(chip, pwm, false, state->polarity);
+		ret = rockchip_pwm_enable(chip, pwm, false, state->polarity);
+		if (ret)
+			goto out;
 		enabled = false;
 	}
 
 	ret = rockchip_pwm_config(chip, pwm, state->duty_cycle, state->period);
 	if (ret) {
 		if (enabled != curstate.enabled)
-			pc->data->set_enable(chip, pwm, !enabled,
-					     state->polarity);
-
+			rockchip_pwm_enable(chip, pwm, !enabled,
+				      state->polarity);
 		goto out;
 	}
 
-	if (state->enabled != enabled)
-		pc->data->set_enable(chip, pwm, state->enabled,
-				     state->polarity);
+	if (state->enabled != enabled) {
+		ret = rockchip_pwm_enable(chip, pwm, state->enabled,
+				    state->polarity);
+		if (ret)
+			goto out;
+	}
 
 	/*
 	 * Update the state with the real hardware, which can differ a bit

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Thread

[PATCH 4.10 00/69] 4.10.12-stable review Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 16:40 +0200
  [PATCH 4.10 18/69] CIFS: store results of cifs_reopen_file to avoid infinite wait Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 16:40 +0200
  [PATCH 4.10 20/69] perf annotate s390: Fix perf annotate error -95 (4.10 regression) Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 16:40 +0200
  [PATCH 4.10 48/69] cpufreq: Bring CPUs up even if cpufreq_online() failed Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 16:40 +0200
  [PATCH 4.10 35/69] scsi: sr: Sanity check returned mode data Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 16:40 +0200
  [PATCH 4.10 15/69] drm/etnaviv: fix missing unlock on error in etnaviv_gpu_submit() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 16:40 +0200
  [PATCH 4.10 08/69] zsmalloc: expand class bit Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 16:40 +0200
  [PATCH 4.10 11/69] drm/nouveau/mmu/nv4a: use nv04 mmu rather than the nv44 one Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 16:40 +0200
  [PATCH 4.10 26/69] x86/vdso: Ensure vdso32_enabled gets set to valid values only Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 16:40 +0200
  [PATCH 4.10 42/69] make skb_copy_datagram_msg() et.al. preserve ->msg_iter on error Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 16:50 +0200
  [PATCH 4.10 67/69] mm: Tighten x86 /dev/mem with zeroing reads Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 16:50 +0200
  [PATCH 4.10 39/69] target: Avoid mappedlun symlink creation during lun shutdown Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 16:50 +0200
  [PATCH 4.10 52/69] char: lack of bool string made CONFIG_DEVPORT always on Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 16:50 +0200
  [PATCH 4.10 34/69] iscsi-target: Drop work-around for legacy GlobalSAN initiator Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 16:50 +0200
  [PATCH 4.10 43/69] libnvdimm: fix blk free space accounting Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 16:50 +0200
  [PATCH 4.10 40/69] xen, fbfront: fix connecting to backend Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 16:50 +0200
  [PATCH 4.10 69/69] virtio-console: avoid DMA from stack Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 16:50 +0200
  [PATCH 4.10 65/69] ACPI / EC: Use busy polling mode when GPE is not enabled Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 16:50 +0200
  [PATCH 4.10 66/69] rtc: tegra: Implement clock handling Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 16:50 +0200
  [PATCH 4.10 41/69] [iov_iter] new privimitive: iov_iter_revert() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 16:50 +0200
  [PATCH 4.10 37/69] scsi: qla2xxx: Add fix to read correct register value for ISP82xx. Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 16:50 +0200
  [PATCH 4.10 56/69] crypto: algif_aead - Fix bogus request dereference in completion function Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 17:20 +0200
  [PATCH 4.10 54/69] zram: do not use copy_page with non-page aligned address Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 17:20 +0200
  [PATCH 4.10 58/69] crypto: ahash - Fix EINPROGRESS notification callback Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 17:20 +0200
  [PATCH 4.10 61/69] [media] dvb-usb-v2: avoid use-after-free Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 17:20 +0200
  [PATCH 4.10 36/69] scsi: sd: Consider max_xfer_blocks if opt_xfer_blocks is unusable Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 17:20 +0200
  [PATCH 4.10 59/69] crypto: lrw - Fix use-after-free on EINPROGRESS Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 17:20 +0200
  [PATCH 4.10 38/69] scsi: sd: Fix capacity calculation with 32-bit sector_t Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 17:20 +0200
  [PATCH 4.10 57/69] crypto: xts - Fix use-after-free on EINPROGRESS Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 17:20 +0200
  [PATCH 4.10 64/69] x86/xen: Fix APIC id mismatch warning on Intel Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 17:20 +0200
  [PATCH 4.10 62/69] ASoC: Intel: select DW_DMAC_CORE since its mandatory Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 17:20 +0200
  [PATCH 4.10 55/69] ftrace: Fix function pid filter on instances Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 17:30 +0200
  [PATCH 4.10 06/69] thp: fix MADV_DONTNEED vs. MADV_FREE race Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 17:30 +0200
  [PATCH 4.10 23/69] x86/signals: Fix lower/upper bound reporting in compat siginfo Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 17:30 +0200
  [PATCH 4.10 45/69] libnvdimm: band aid btt vs clear poison locking Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 17:30 +0200
  [PATCH 4.10 07/69] thp: fix MADV_DONTNEED vs clear soft dirty race Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 17:30 +0200
  [PATCH 4.10 50/69] ftrace: Fix removing of second function probe Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 17:30 +0200
  [PATCH 4.10 49/69] irqchip/irq-imx-gpcv2: Fix spinlock initialization Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 17:30 +0200
  [PATCH 4.10 51/69] drm/i915/gvt: set the correct default value of CTX STATUS PTR Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 17:30 +0200
  [PATCH 4.10 46/69] can: ifi: use correct register to read rx status Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 17:30 +0200
  [PATCH 4.10 31/69] efi/libstub: Skip GOP with PIXEL_BLT_ONLY format Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 17:30 +0200
  [PATCH 4.10 22/69] x86/efi: Dont try to reserve runtime regions Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 17:30 +0200
  [PATCH 4.10 25/69] x86, pmem: fix broken __copy_user_nocache cache-bypass assumptions Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 17:30 +0200
  [PATCH 4.10 28/69] acpi, nfit, libnvdimm: fix interleave set cookie calculation (64-bit comparison) Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 17:30 +0200
  [PATCH 4.10 27/69] x86/vdso: Plug race between mapping and ELF header setup Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 17:30 +0200
  [PATCH 4.10 53/69] Revert "MIPS: Lantiq: Fix cascaded IRQ setup" Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 17:30 +0200
  [PATCH 4.10 32/69] efi/fb: Avoid reconfiguration of BAR that covers the framebuffer Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 17:30 +0200
  [PATCH 4.10 09/69] orangefs: free superblock when mount fails Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 17:30 +0200
  [PATCH 4.10 03/69] tcmu: Fix possible overwrite of t_data_sgs last iov[] Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 17:30 +0200
  [PATCH 4.10 04/69] tcmu: Fix wrongly calculating of the base_command_size Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 17:30 +0200
  [PATCH 4.10 29/69] ACPI / scan: Set the visited flag for all enumerated devices Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 17:30 +0200
  [PATCH 4.10 47/69] pwm: rockchip: State of PWM clock should synchronize with PWM enabled state Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 17:30 +0200
  [PATCH 4.10 05/69] tcmu: Skip Data-Out blocks before gathering Data-In buffer for BIDI case Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 17:30 +0200
  [PATCH 4.10 60/69] parisc: Fix get_user() for 64-bit value on 32-bit kernel Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 17:30 +0200
  [PATCH 4.10 44/69] libnvdimm: fix reconfig_mutex, mmap_sem, and jbd2_handle lockdep splat Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 17:30 +0200
  [PATCH 4.10 19/69] Input: xpad - add support for Razer Wildcat gamepad Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 17:40 +0200
  [PATCH 4.10 17/69] CIFS: reconnect thread reschedule itself Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 17:40 +0200
  [PATCH 4.10 13/69] drm/nouveau/kms/nv50: fix double dma_fence_put() when destroying plane state Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 17:40 +0200
  [PATCH 4.10 02/69] audit: make sure we dont let the retry queue grow without bounds Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 17:40 +0200
  [PATCH 4.10 01/69] cgroup, kthread: close race window where new kthreads can be migrated to non-root cgroups Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 17:40 +0200
  [PATCH 4.10 10/69] drm/nouveau/mpeg: mthd returns true on success now Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 17:40 +0200
  [PATCH 4.10 12/69] drm/nouveau/kms/nv50: fix setting of HeadSetRasterVertBlankDmi method Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-19 17:40 +0200
  Re: [PATCH 4.10 00/69] 4.10.12-stable review Shuah Khan <shuahkh@osg.samsung.com> - 2017-04-19 22:40 +0200
    Re: [PATCH 4.10 00/69] 4.10.12-stable review Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-20 08:40 +0200
  Re: [PATCH 4.10 00/69] 4.10.12-stable review Guenter Roeck <linux@roeck-us.net> - 2017-04-20 01:30 +0200
    Re: [PATCH 4.10 00/69] 4.10.12-stable review Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-20 08:40 +0200

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