From: Bhuvanchandra DV <bhuvanchandra.dv@toradex.com>
To: <shawnguo@kernel.org>, <thierry.reding@gmail.com>
Cc: <stefan@agner.ch>, <l.majewski@samsung.com>, <robh+dt@kernel.org>,
<mark.rutland@arm.com>, <kernel@pengutronix.de>,
<fabio.estevam@nxp.com>, <linux-pwm@vger.kernel.org>,
<devicetree@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
<linux-arm-kernel@lists.infradead.org>,
Lothar Wassmann <LW@KARO-electronics.de>,
Bhuvanchandra DV <bhuvanchandra.dv@toradex.com>
Subject: [PATCH v3 3/6] pwm: imx: support output polarity inversion
Date: Fri, 7 Oct 2016 20:41:26 +0530 [thread overview]
Message-ID: <20161007151129.6043-4-bhuvanchandra.dv@toradex.com> (raw)
In-Reply-To: <20161007151129.6043-1-bhuvanchandra.dv@toradex.com>
From: Lothar Wassmann <LW@KARO-electronics.de>
The i.MX pwm unit on i.MX27 and newer SoCs provides a configurable output
polarity. This patch adds support to utilize this feature where available.
Signed-off-by: Lothar Waßmann <LW@KARO-electronics.de>
Signed-off-by: Lukasz Majewski <l.majewski@samsung.com>
Signed-off-by: Bhuvanchandra DV <bhuvanchandra.dv@toradex.com>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Reviewed-by: Sascha Hauer <s.hauer@pengutronix.de>
---
Documentation/devicetree/bindings/pwm/imx-pwm.txt | 6 +--
drivers/pwm/pwm-imx.c | 51 +++++++++++++++++++++--
2 files changed, 51 insertions(+), 6 deletions(-)
diff --git a/Documentation/devicetree/bindings/pwm/imx-pwm.txt b/Documentation/devicetree/bindings/pwm/imx-pwm.txt
index e00c2e9..c61bdf8 100644
--- a/Documentation/devicetree/bindings/pwm/imx-pwm.txt
+++ b/Documentation/devicetree/bindings/pwm/imx-pwm.txt
@@ -6,8 +6,8 @@ Required properties:
- "fsl,imx1-pwm" for PWM compatible with the one integrated on i.MX1
- "fsl,imx27-pwm" for PWM compatible with the one integrated on i.MX27
- reg: physical base address and length of the controller's registers
-- #pwm-cells: should be 2. See pwm.txt in this directory for a description of
- the cells format.
+- #pwm-cells: 2 for i.MX1 and 3 for i.MX27 and newer SoCs. See pwm.txt
+ in this directory for a description of the cells format.
- clocks : Clock specifiers for both ipg and per clocks.
- clock-names : Clock names should include both "ipg" and "per"
See the clock consumer binding,
@@ -17,7 +17,7 @@ See the clock consumer binding,
Example:
pwm1: pwm@53fb4000 {
- #pwm-cells = <2>;
+ #pwm-cells = <3>;
compatible = "fsl,imx53-pwm", "fsl,imx27-pwm";
reg = <0x53fb4000 0x4000>;
clocks = <&clks IMX5_CLK_PWM1_IPG_GATE>,
diff --git a/drivers/pwm/pwm-imx.c b/drivers/pwm/pwm-imx.c
index d600fd5..c37d223 100644
--- a/drivers/pwm/pwm-imx.c
+++ b/drivers/pwm/pwm-imx.c
@@ -38,6 +38,7 @@
#define MX3_PWMCR_DOZEEN (1 << 24)
#define MX3_PWMCR_WAITEN (1 << 23)
#define MX3_PWMCR_DBGEN (1 << 22)
+#define MX3_PWMCR_POUTC (1 << 18)
#define MX3_PWMCR_CLKSRC_IPG_HIGH (2 << 16)
#define MX3_PWMCR_CLKSRC_IPG (1 << 16)
#define MX3_PWMCR_SWR (1 << 3)
@@ -180,6 +181,9 @@ static int imx_pwm_config_v2(struct pwm_chip *chip,
if (enable)
cr |= MX3_PWMCR_EN;
+ if (pwm->args.polarity == PWM_POLARITY_INVERSED)
+ cr |= MX3_PWMCR_POUTC;
+
writel(cr, imx->mmio_base + MX3_PWMCR);
return 0;
@@ -240,27 +244,62 @@ static void imx_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
clk_disable_unprepare(imx->clk_per);
}
-static struct pwm_ops imx_pwm_ops = {
+static int imx_pwm_set_polarity(struct pwm_chip *chip, struct pwm_device *pwm,
+ enum pwm_polarity polarity)
+{
+ struct imx_chip *imx = to_imx_chip(chip);
+ u32 val;
+
+ if (polarity == pwm->args.polarity)
+ return 0;
+
+ val = readl(imx->mmio_base + MX3_PWMCR);
+
+ if (polarity == PWM_POLARITY_INVERSED)
+ val |= MX3_PWMCR_POUTC;
+ else
+ val &= ~MX3_PWMCR_POUTC;
+
+ writel(val, imx->mmio_base + MX3_PWMCR);
+
+ dev_dbg(imx->chip.dev, "%s: polarity set to %s\n", __func__,
+ polarity == PWM_POLARITY_INVERSED ? "inverted" : "normal");
+
+ return 0;
+}
+
+static struct pwm_ops imx_pwm_ops_v1 = {
.enable = imx_pwm_enable,
.disable = imx_pwm_disable,
.config = imx_pwm_config,
.owner = THIS_MODULE,
};
+static struct pwm_ops imx_pwm_ops_v2 = {
+ .enable = imx_pwm_enable,
+ .disable = imx_pwm_disable,
+ .set_polarity = imx_pwm_set_polarity,
+ .config = imx_pwm_config,
+ .owner = THIS_MODULE,
+};
+
struct imx_pwm_data {
int (*config)(struct pwm_chip *chip,
struct pwm_device *pwm, int duty_ns, int period_ns);
void (*set_enable)(struct pwm_chip *chip, bool enable);
+ struct pwm_ops *pwm_ops;
};
static struct imx_pwm_data imx_pwm_data_v1 = {
.config = imx_pwm_config_v1,
.set_enable = imx_pwm_set_enable_v1,
+ .pwm_ops = &imx_pwm_ops_v1,
};
static struct imx_pwm_data imx_pwm_data_v2 = {
.config = imx_pwm_config_v2,
.set_enable = imx_pwm_set_enable_v2,
+ .pwm_ops = &imx_pwm_ops_v2,
};
static const struct of_device_id imx_pwm_dt_ids[] = {
@@ -282,6 +321,8 @@ static int imx_pwm_probe(struct platform_device *pdev)
if (!of_id)
return -ENODEV;
+ data = of_id->data;
+
imx = devm_kzalloc(&pdev->dev, sizeof(*imx), GFP_KERNEL);
if (imx == NULL)
return -ENOMEM;
@@ -300,18 +341,22 @@ static int imx_pwm_probe(struct platform_device *pdev)
return PTR_ERR(imx->clk_ipg);
}
- imx->chip.ops = &imx_pwm_ops;
+ imx->chip.ops = data->pwm_ops;
imx->chip.dev = &pdev->dev;
imx->chip.base = -1;
imx->chip.npwm = 1;
imx->chip.can_sleep = true;
+ if (data->pwm_ops->set_polarity) {
+ dev_dbg(&pdev->dev, "PWM supports output inversion\n");
+ imx->chip.of_xlate = of_pwm_xlate_with_flags;
+ imx->chip.of_pwm_n_cells = 3;
+ }
r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
imx->mmio_base = devm_ioremap_resource(&pdev->dev, r);
if (IS_ERR(imx->mmio_base))
return PTR_ERR(imx->mmio_base);
- data = of_id->data;
imx->config = data->config;
imx->set_enable = data->set_enable;
--
2.10.0
next prev parent reply other threads:[~2016-10-07 17:46 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-10-07 15:11 [PATCH v3 0/6] Support PWM polarity control Bhuvanchandra DV
2016-10-07 15:11 ` [PATCH v3 1/6] pwm: print error messages with pr_err() instead of pr_debug() Bhuvanchandra DV
2016-10-07 15:11 ` [PATCH v3 2/6] pwm: core: make the PWM_POLARITY flag in DTB optional Bhuvanchandra DV
2016-10-07 15:11 ` Bhuvanchandra DV [this message]
2016-10-08 14:32 ` [PATCH v3 3/6] pwm: imx: support output polarity inversion Lukasz Majewski
2016-10-10 17:10 ` Rob Herring
2016-10-10 21:01 ` Stefan Agner
2016-10-12 22:15 ` Lukasz Majewski
2016-10-12 23:18 ` Stefan Agner
2016-10-13 4:58 ` Lukasz Majewski
2016-10-20 8:30 ` Lukasz Majewski
2016-10-20 22:46 ` Stefan Agner
2016-10-21 21:49 ` Lukasz Majewski
2016-10-22 10:57 ` Boris Brezillon
2016-10-22 12:01 ` Boris Brezillon
2016-10-23 6:40 ` Lukasz Majewski
2016-10-22 10:33 ` Boris Brezillon
2016-10-07 15:11 ` [PATCH v3 4/6] arm: dts: imx7: Update #pwm-cells for PWM polarity control Bhuvanchandra DV
2016-10-07 15:11 ` [PATCH v3 5/6] arm: dts: imx7-colibri: Use pwm " Bhuvanchandra DV
2016-10-07 15:11 ` [PATCH v3 6/6] arm: dts: imx7-colibri: Use enable-gpios for BL_ON Bhuvanchandra DV
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