Hi Ezequiel,
On 07.01.2015 19:20, Ezequiel Garcia wrote:
> From: Naidu Tellapati <Naidu.Tellapati@xxxxxxxxxx>
>
> The Pistachio SOC from Imagination Technologies includes a Pulse Width
> Modulation DAC which produces 1 to 4 digital bit-outputs which represent
> digital waveforms. These PWM outputs are primarily in charge of controlling
> backlight LED devices.
>
> Reviewed-by: Andrew Bresticker <abrestic@xxxxxxxxxxxx>
> Signed-off-by: Naidu Tellapati <Naidu.Tellapati@xxxxxxxxxx>
> Signed-off-by: Sai Masarapu <Sai.Masarapu@xxxxxxxxxx>
> Signed-off-by: Ezequiel Garcia <ezequiel.garcia@xxxxxxxxxx>
> ---
> drivers/pwm/Kconfig | 13 +++
> drivers/pwm/Makefile | 1 +
> drivers/pwm/pwm-img.c | 250 ++++++++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 264 insertions(+)
> create mode 100644 drivers/pwm/pwm-img.c
>
[snip]
> +static int img_pwm_probe(struct platform_device *pdev)
> +{
> + int ret;
> + struct resource *res;
> + struct img_pwm_chip *pwm;
> +
> + pwm = devm_kzalloc(&pdev->dev, sizeof(*pwm), GFP_KERNEL);
> + if (!pwm)
> + return -ENOMEM;
> +
> + pwm->dev = &pdev->dev;
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + pwm->base = devm_ioremap_resource(&pdev->dev, res);
> + if (IS_ERR(pwm->base))
> + return PTR_ERR(pwm->base);
> +
> + pwm->periph_regs = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
> + "img,cr-periph");
> + if (IS_ERR(pwm->periph_regs))
> + return PTR_ERR(pwm->periph_regs);
> +
> + pwm->sys_clk = devm_clk_get(&pdev->dev, "sys");
> + if (IS_ERR(pwm->sys_clk)) {
> + dev_err(&pdev->dev, "failed to get system clock\n");
> + return PTR_ERR(pwm->sys_clk);
> + }
> +
> + pwm->pwm_clk = devm_clk_get(&pdev->dev, "pwm");
> + if (IS_ERR(pwm->pwm_clk)) {
> + dev_err(&pdev->dev, "failed to get pwm clock\n");
> + return PTR_ERR(pwm->pwm_clk);
> + }
> +
> + ret = clk_prepare_enable(pwm->sys_clk);
> + if (ret < 0) {
> + dev_err(&pdev->dev, "could not prepare or enable sys clock\n");
> + return ret;
> + }
> +
> + ret = clk_prepare_enable(pwm->pwm_clk);
> + if (ret < 0) {
> + dev_err(&pdev->dev, "could not prepare or enable pwm clock\n");
> + goto disable_sysclk;
> + }
> +
> + pwm->chip.dev = &pdev->dev;
> + pwm->chip.ops = &img_pwm_ops;
> + pwm->chip.base = -1;
> + pwm->chip.npwm = 4;
> +
> + ret = pwmchip_add(&pwm->chip);
> + if (ret < 0) {
> + dev_err(&pdev->dev, "pwmchip_add failed: %d\n", ret);
> + goto disable_pwmclk;
> + }
> +
> + platform_set_drvdata(pdev, pwm);
> +
> +disable_pwmclk:
> + clk_disable_unprepare(pwm->pwm_clk);
> +disable_sysclk:
> + clk_disable_unprepare(pwm->sys_clk);
> +
> + return 0;
return ret on error paths?
Also should you reenable sys and pwm clocks after successful driver
registration?
> +}
> +
--
With best wishes,
Vladimir
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