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| author |   Linus Torvalds <torvalds@linux-foundation.org> | 2014-10-21 08:17:43 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-10-21 08:17:43 -0700 |
| commit | 5b9c8972527fdb52d5cd7dadc9853c57430e0ff5 (patch) | |
| tree | a829bb857ae7f19369fd7479597c640d30e0f47e /drivers/pwm/pwm-atmel.c | |
| parent | Merge tag 'arc-3.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc (diff) | |
| parent | pwm: Let PWM_CLPS711X depend on HAS_IOMEM (diff) | |
| download | linux-dev-5b9c8972527fdb52d5cd7dadc9853c57430e0ff5.tar.xz linux-dev-5b9c8972527fdb52d5cd7dadc9853c57430e0ff5.zip | |
Merge tag 'pwm/for-3.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm
Pull pwm changes from Thierry Reding:
"There are no new drivers here, only a couple of fixes all over the
place"
* tag 'pwm/for-3.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm:
pwm: Let PWM_CLPS711X depend on HAS_IOMEM
pwm: atmel: Fix calculation of prescale value
pwm: Fix uninitialized warnings in pwm_get()
pwm: rockchip: Allow polarity invert on rk3288
pwm: imx: Avoid sample FIFO overflow for i.MX PWM version2
pwm: imx: Cleanup indentation for register definitions
pwm: imx: Fix the macro MX3_PWMCR_PRESCALER(x) definition
pwm: Fix possible ZERO_SIZE_PTR pointer dereferencing error.
pwm: lpss: make it buildable only on X86
pwm: lpss: use c99 initializers in structures
pwm: lpss: Fix build failure on PowerPC
pwm: lpss: pci: Move to use pcim_enable_device()
pwm: lpss: Properly split driver to parts
pwm: lpss: Add ACPI and PCI IDs for Intel Braswell
pwm: fsl-ftm: Select REGMAP_MMIO
pwm: fsl-ftm: Document 'big-endian' property
pwm: fsl-ftm: Convert to direct regmap API usage
pwm: fsl-ftm: Clean up the code
Diffstat (limited to 'drivers/pwm/pwm-atmel.c')
| -rw-r--r-- | drivers/pwm/pwm-atmel.c | 24 |
1 files changed, 11 insertions, 13 deletions
diff --git a/drivers/pwm/pwm-atmel.c b/drivers/pwm/pwm-atmel.c index 6e700a541ca3..d3c22de9ee47 100644 --- a/drivers/pwm/pwm-atmel.c +++ b/drivers/pwm/pwm-atmel.c @@ -102,7 +102,7 @@ static int atmel_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, int duty_ns, int period_ns) { struct atmel_pwm_chip *atmel_pwm = to_atmel_pwm_chip(chip); - unsigned long clk_rate, prd, dty; + unsigned long prd, dty; unsigned long long div; unsigned int pres = 0; u32 val; @@ -113,20 +113,18 @@ static int atmel_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, return -EBUSY; } - clk_rate = clk_get_rate(atmel_pwm->clk); - div = clk_rate; + /* Calculate the period cycles and prescale value */ + div = (unsigned long long)clk_get_rate(atmel_pwm->clk) * period_ns; + do_div(div, NSEC_PER_SEC); - /* Calculate the period cycles */ while (div > PWM_MAX_PRD) { - div = clk_rate / (1 << pres); - div = div * period_ns; - /* 1/Hz = 100000000 ns */ - do_div(div, 1000000000); - - if (pres++ > PRD_MAX_PRES) { - dev_err(chip->dev, "pres exceeds the maximum value\n"); - return -EINVAL; - } + div >>= 1; + pres++; + } + + if (pres > PRD_MAX_PRES) { + dev_err(chip->dev, "pres exceeds the maximum value\n"); + return -EINVAL; } /* Calculate the duty cycles */ |