Commit Graph

17 Commits

Author SHA1 Message Date
Andy Shevchenko d9cd4a7369 pwm: lpss: Move clk_rate check to ->probe()
There is no need to check each time if the clk_rate defined or not when we call
pwm_lpss_config(). Move the check to ->probe() instead.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-07-11 12:49:24 +02:00
Mika Westerberg ab248b6039 pwm: lpss: Prevent on_time_div overflow on lower frequencies
If duty_ns is large enough multiplying it by 255 overflows and results
wrong duty cycle value being programmed. For example with 10ms duty when
period is 20ms (50%) we get

  255 * 10000000 / 20000000 = -87

because 255 * 10000000 overlows int. Whereas correct value should be

  255 * 10000000 / 20000000 = 127

Fix this by using unsigned long long as type for on_time_div and changing
integer literals to use proper type annotation.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-07-11 12:07:24 +02:00
Dan O'Donovan e5ca42458b pwm: lpss: Fix base_unit calculation for PWM frequency
The base_unit calculation applies an offset of 0x2 which adds
significant error for lower frequencies and doesn't appear to be
warranted - rounding the division result gives a correct value.

Also, the upper limit check for base_unit is off-by-one; the upper
nibble of base_unit is invalid if >=128 according to the Table 88
in the Z8000 Processor Series Datasheet Volume 1 (Rev. 2).

Verified on UP Board (Cherry Trail) and Minnowboard Max (Bay Trail).

Signed-off-by: Dan O'Donovan <dan@emutex.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-07-11 12:07:23 +02:00
Mika Westerberg 37670676a1 pwm: lpss: Rework the sequence of programming PWM_SW_UPDATE
Setting of PWM_SW_UPDATE is bit different in Intel Broxton compared to the
previous generation SoCs. Previously it was OK to set the bit many times
(from userspace via sysfs for example) before the PWM is actually enabled.

Starting from Intel Broxton it seems that we must set PWM_SW_UPDATE only
once before the PWM is enabled. Otherwise it is possible that the PWM does
not start properly.

Change the sequence of how PWM_SW_UPDATE is programmed so that we only set
it in pwm_lpss_config() when the PWM is already enabled. The initial
setting of PWM_SW_UPDATE will be done when PWM gets enabled. This should
make the driver work with the previous generation Intel SoCs and Broxton.

Add also small delay after the bit is set to let the hardware propagate it
properly.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-12-16 16:52:09 +01:00
qipeng.zha 883e4d070f pwm: lpss: Update PWM setting for Broxton
For Broxton PWM controller, base unit is defined as 8-bit integer
and 14-bit fraction, so need to update base unit setting to output
wave with right frequency.

Signed-off-by: Qipeng Zha <qipeng.zha@intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-12-16 16:45:38 +01:00
Mika Westerberg c7b91b33cf pwm: lpss: Remove ->free() callback
The LPSS PWM driver calls pwm_lpss_disable() when the PWM device is
released (for example unexported from sysfs). This in turn calls
pm_runtime_put() which makes runtime PM count to be unbalanced if the
device has not been enabled at this point.

This is easy to reproduce:

  # cd /sys/class/pwm/pwmchip0
  # echo 0 > export
  # echo 0 > unexport

The count is unbalanced and prevents the PWM device from being powered on
next time.

Fix this by removing ->free() callback. There are no resources to be
released anyway.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-12-16 16:31:27 +01:00
Qipeng Zha f080be27d7 pwm: lpss: Add support for runtime PM
To be able to save some power when PWM is not in use, add support for
runtime PM for this driver. This also allows the platform to transition to
low power S0ix states when the system is idle.

Signed-off-by: Huiquan Zhong <huiquan.zhong@intel.com>
Signed-off-by: Qipeng Zha <qipeng.zha@intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-11-06 14:34:13 +01:00
Mika Westerberg 87219cb47e pwm: lpss: Support all four PWMs on Intel Broxton
Intel Broxton has similar PWM than Intel Braswell but instead of one it has
four PWMs included in one PCI/ACPI device. This patch adds support for all
the four PWMs and changes the PCI part of the driver to use
'pwm_lpss_bxt_info' instead.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-11-06 14:26:28 +01:00
Mika Westerberg 4e11f5acb2 pwm: lpss: Add support for multiple PWMs
New Intel SoCs such as Broxton will have four PWMs per PCI (or ACPI)
device. Each PWM has 1k of register space allocated from the parent device.
Add support for this.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-11-06 14:26:27 +01:00
Julia Lawall b2b7adeb21 pwm: lpss: use c99 initializers in structures
Use c99 initializers for structures.

A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@decl@
identifier i1,fld;
type T;
field list[n] fs;
@@

struct i1 {
 fs
 T fld;
 ...};

@bad@
identifier decl.i1,i2;
expression e;
initializer list[decl.n] is;
@@

struct i1 i2 = { is,
+ .fld = e
- e
 ,...};
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
[thierry.reding: rebased and applied same fix for Braswell]
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2014-08-25 11:45:34 +02:00
Thierry Reding e0c86a3b63 pwm: lpss: Fix build failure on PowerPC
An x86 build seems to pull in the linux/io.h include indirectly. On
PowerPC that doesn't happen and the build breaks due to the readl() and
writel() functions not being declared. Fix this by explicitly including
linux/io.h.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2014-08-23 00:25:52 +02:00
Andy Shevchenko c558e39e14 pwm: lpss: Properly split driver to parts
The driver consists of core, PCI, and platform parts. It would be better
to split them into separate files.

The platform driver is now called pwm-lpss-platform. Thus, previously
set CONFIG_PWM_LPSS=m is not enough to build it. But we are on the safe
side since it seems no one from outside Intel is using it for now.

While here, move to use macros module_pci_driver() and
module_platform_driver().

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Alan Cox <alan@linux.intel.com>
[thierry.reding: change select to depends on PWM_LPSS, cleanup]
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2014-08-23 00:25:47 +02:00
Alan Cox 373c57829a pwm: lpss: Add ACPI and PCI IDs for Intel Braswell
This is pretty much the same as Baytrail PWM. Only difference is that the
input clock runs on different frequency.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2014-08-22 11:52:30 +02:00
Heikki Krogerus 65accd8738 pwm: lpss: remove dependency on clk framework
Unlike other Intel LPSS devices, the PWM does not have the
clock dividers or the gate. All we get from the clock is the
rate. Since PCI case uses the driver data to get the rate,
we can drop the clk and use the same data also in case of
ACPI. The frequency is the same.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Chew, Chiau Ee <chiau.ee.chew@intel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2014-08-07 13:18:03 +02:00
Thierry Reding 89c0339e0a pwm: lpss: Fix const qualifier and sparse warnings
Fixes the following warnings reported by the 0-DAY kernel build testing
backend:

   drivers/pwm/pwm-lpss.c: In function 'pwm_lpss_probe_pci':
>> drivers/pwm/pwm-lpss.c:192:2: warning: passing argument 3 of 'pwm_lpss_probe' discards 'const' qualifier from pointer target type [enabled by default]
     lpwm = pwm_lpss_probe(&pdev->dev, &pdev->resource[0], info);
     ^
   drivers/pwm/pwm-lpss.c:130:30: note: expected 'struct pwm_lpss_boardinfo *' but argument is of type 'const struct pwm_lpss_boardinfo *'
    static struct pwm_lpss_chip *pwm_lpss_probe(struct device *dev,
                                 ^
>> drivers/pwm/pwm-lpss.c:143:28: sparse: incorrect type in return expression (different address spaces)
   drivers/pwm/pwm-lpss.c:143:28:    expected struct pwm_lpss_chip *
   drivers/pwm/pwm-lpss.c:143:28:    got void [noderef] <asn:2>*regs
>> drivers/pwm/pwm-lpss.c:192:63: sparse: incorrect type in argument 3 (different modifiers)
   drivers/pwm/pwm-lpss.c:192:63:    expected struct pwm_lpss_boardinfo *info
   drivers/pwm/pwm-lpss.c:192:63:    got struct pwm_lpss_boardinfo const *[assigned] info
   drivers/pwm/pwm-lpss.c: In function 'pwm_lpss_probe_pci':
   drivers/pwm/pwm-lpss.c:192:2: warning: passing argument 3 of 'pwm_lpss_probe' discards 'const' qualifier from pointer target type [enabled by default]
     lpwm = pwm_lpss_probe(&pdev->dev, &pdev->resource[0], info);
     ^
   drivers/pwm/pwm-lpss.c:130:30: note: expected 'struct pwm_lpss_boardinfo *' but argument is of type 'const struct pwm_lpss_boardinfo *'
    static struct pwm_lpss_chip *pwm_lpss_probe(struct device *dev,
                                 ^

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2014-05-07 10:27:57 +02:00
Alan Cox 093e00bb3f pwm: lpss: Add support for PCI devices
Not all systems enumerate the PWM devices via ACPI. They can also be
exposed via the PCI interface.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Chew, Chiau Ee <chiau.ee.chew@intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2014-04-28 13:47:03 +02:00
Mika Westerberg d16a5aa9e8 pwm: add support for Intel Low Power Subsystem PWM
Add support for Intel Low Power I/O subsystem PWM controllers found on
Intel BayTrail SoC.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Chew, Kean Ho <kean.ho.chew@intel.com>
Signed-off-by: Chang, Rebecca Swee Fun <rebecca.swee.fun.chang@intel.com>
Signed-off-by: Chew, Chiau Ee <chiau.ee.chew@intel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2014-04-01 12:03:40 +02:00