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From: Lee Jones <lee.jones@linaro.org>
To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
Cc: kernel@stlinux.com, maxime.coquelin@st.com,
	patrice.chotard@st.com, thierry.reding@gmail.com,
	robh+dt@kernel.org, linux-pwm@vger.kernel.org,
	devicetree@vger.kernel.org, Lee Jones <lee.jones@linaro.org>
Subject: [PATCH v3 18/20] pwm: sti: It's now valid for number of PWM channels to be zero
Date: Wed,  8 Jun 2016 10:21:33 +0100	[thread overview]
Message-ID: <20160608092135.21184-19-lee.jones@linaro.org> (raw)
In-Reply-To: <20160608092135.21184-1-lee.jones@linaro.org>

Setting up the STI PWM IP as capture only, with zero PWM-out devices
is a perfectly valued configuration.  It is no longer okay to assume
that there must be at least 1 PWM-out devices.  In this patch we make
the default number of PWM-out devices zero and only configure channels
explicitly requested.

Reported-by: Peter Griffin <peter.griffin@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
---
 drivers/pwm/pwm-sti.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/pwm/pwm-sti.c b/drivers/pwm/pwm-sti.c
index cecb6d4..64db5a5 100644
--- a/drivers/pwm/pwm-sti.c
+++ b/drivers/pwm/pwm-sti.c
@@ -483,6 +483,11 @@ static int sti_pwm_probe_dt(struct sti_pwm_chip *pc)
 	if (!ret)
 		cdata->cpt_num_devs = num_devs;
 
+	if (cdata->pwm_num_devs && !cdata->cpt_num_devs) {
+		dev_err(dev, "No channels configured\n");
+		return -EINVAL;
+	}
+
 	reg_fields = cdata->reg_fields;
 
 	pc->prescale_low = devm_regmap_field_alloc(dev, pc->regmap,
@@ -573,7 +578,7 @@ static int sti_pwm_probe(struct platform_device *pdev)
 	cdata->reg_fields   = &sti_pwm_regfields[0];
 	cdata->max_prescale = 0xff;
 	cdata->max_pwm_cnt  = 255;
-	cdata->pwm_num_devs = 1;
+	cdata->pwm_num_devs = 0;
 	cdata->cpt_num_devs = 0;
 
 	pc->cdata = cdata;
@@ -585,6 +590,9 @@ static int sti_pwm_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
+	if (!cdata->pwm_num_devs)
+		goto skip_pwm;
+
 	pc->pwm_clk = of_clk_get_by_name(dev->of_node, "pwm");
 	if (IS_ERR(pc->pwm_clk)) {
 		dev_err(dev, "failed to get PWM clock\n");
@@ -597,6 +605,10 @@ static int sti_pwm_probe(struct platform_device *pdev)
 		return ret;
 	}
 
+skip_pwm:
+	if (!cdata->cpt_num_devs)
+		goto skip_cpt;
+
 	pc->cpt_clk = of_clk_get_by_name(dev->of_node, "capture");
 	if (IS_ERR(pc->cpt_clk)) {
 		dev_err(dev, "failed to get PWM capture clock\n");
@@ -609,6 +621,7 @@ static int sti_pwm_probe(struct platform_device *pdev)
 		return ret;
 	}
 
+skip_cpt:
 	pc->chip.dev = dev;
 	pc->chip.ops = &sti_pwm_ops;
 	pc->chip.base = -1;
-- 
2.8.3

  parent reply	other threads:[~2016-06-08  9:23 UTC|newest]

Thread overview: 35+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-06-08  9:21 [PATCH v3 00/20] pwm: Add support for PWM Capture Lee Jones
2016-06-08  9:21 ` [PATCH v3 01/20] ARM: dts: STi: Rename properites in line with PWM naming conventions Lee Jones
2016-06-08  9:21 ` [PATCH v3 02/20] ARM: dts: STiH407: Supply PWM Capture IRQ Lee Jones
2016-06-08  9:21 ` [PATCH v3 03/20] ARM: dts: STiH407: Declare PWM Capture data lines via Pinctrl Lee Jones
2016-06-08  9:21 ` [PATCH v3 04/20] ARM: dts: STiH416: Supply PWM Capture IRQs Lee Jones
2016-06-08  9:21 ` [PATCH v3 05/20] ARM: dts: STiH416: Declare PWM Capture data lines via Pinctrl Lee Jones
2016-06-08  9:21 ` [PATCH v3 06/20] ARM: dts: STiH416: Define PWM Capture clock Lee Jones
2016-06-08  9:21 ` [PATCH v3 07/20] ARM: dts: STiH416: Define the number of PWM Capture channels Lee Jones
2016-06-08  9:21 ` [PATCH v3 08/20] pwm: Add PWM Capture support Lee Jones
2016-06-10 13:53   ` Thierry Reding
2016-06-10 14:38     ` Lee Jones
2016-06-10 16:39       ` Thierry Reding
2016-06-20 11:14         ` Lee Jones
2016-06-08  9:21 ` [PATCH v3 09/20] pwm: sti: Rename channel => device Lee Jones
2016-06-08  9:21 ` [PATCH v3 10/20] pwm: sysfs: Add PWM Capture support Lee Jones
2016-06-10 14:04   ` Thierry Reding
2016-06-10 14:36     ` Lee Jones
2016-06-08  9:21 ` [PATCH v3 11/20] pwm: sti: Reorganise register names in preparation for new functionality Lee Jones
2016-06-08  9:21 ` [PATCH v3 12/20] pwm: sti: Only request clock rate when you need to Lee Jones
2016-06-08  9:21 ` [PATCH v3 13/20] pwm: sti: Supply PWM Capture register addresses and bit locations Lee Jones
2016-06-08  9:21 ` [PATCH v3 14/20] pwm: sti: Supply PWM Capture clock handling Lee Jones
2016-06-08  9:21 ` [PATCH v3 15/20] pwm: sti: Initialise PWM Capture device data Lee Jones
2016-06-08  9:21 ` [PATCH v3 16/20] pwm: sti: Add support for PWM Capture IRQs Lee Jones
2016-06-08  9:21 ` [PATCH v3 17/20] pwm: sti: Add PWM Capture call-back Lee Jones
2016-06-08  9:21 ` Lee Jones [this message]
2016-06-08  9:21 ` [PATCH v3 19/20] pwm: sti: Take the opportunity to conduct a little house keeping Lee Jones
2016-06-08  9:21 ` [PATCH v3 20/20] dt-bindings: pwm: sti: Update DT bindings with recent changes Lee Jones
2016-06-08 20:51   ` Rob Herring
2016-06-09 11:41     ` Lee Jones
2016-06-10 13:18       ` Thierry Reding
2016-06-10 14:06         ` Lee Jones
2016-06-10 14:53           ` Thierry Reding
2016-06-10 15:19             ` Lee Jones
2016-07-13  9:02             ` Lee Jones
2016-06-10 13:10     ` Thierry Reding

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