[PATCH v3 1/5] pwms: pwm-ti*: Remove support for local clock gating

[Franklin S Cooper Jr <fcooper@ti.com>]

The PWMSS local clock gating registers have no real purpose on OMAP ARM
devices. These registers were left over registers from DSP IP where the
PRCM doesn't exist. There is a silicon bug where gating and ungating clocks
don't function properly. TRMs will be update to indicate that these
registers shouldn't be touched.

Therefore, all code that accesses the PWMSS_CLKCONFIG or PWMSS_CLKSTATUS
will be removed by this patch with zero loss of functionality by the ECAP
and EPWM drivers.

Signed-off-by: Franklin S Cooper Jr <fcooper@ti.com>
---
Version 3 changes:
New patch

 drivers/pwm/pwm-tiecap.c   | 28 --------------------------
 drivers/pwm/pwm-tiehrpwm.c | 29 ---------------------------
 drivers/pwm/pwm-tipwmss.c  | 49 ----------------------------------------------
 drivers/pwm/pwm-tipwmss.h  | 39 ------------------------------------
 4 files changed, 145 deletions(-)
 delete mode 100644 drivers/pwm/pwm-tipwmss.h

diff --git a/drivers/pwm/pwm-tiecap.c b/drivers/pwm/pwm-tiecap.c
index 616af76..9e0865d7 100644
--- a/drivers/pwm/pwm-tiecap.c
+++ b/drivers/pwm/pwm-tiecap.c
@@ -27,8 +27,6 @@
 #include <linux/pwm.h>
 #include <linux/of_device.h>
 
-#include "pwm-tipwmss.h"
-
 /* ECAP registers and bits definitions */
 #define CAP1			0x08
 #define CAP2			0x0C
@@ -206,7 +204,6 @@ static int ecap_pwm_probe(struct platform_device *pdev)
 	struct resource *r;
 	struct clk *clk;
 	struct ecap_pwm_chip *pc;
-	u16 status;
 
 	pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL);
 	if (!pc)
@@ -243,40 +240,15 @@ static int ecap_pwm_probe(struct platform_device *pdev)
 	}
 
 	pm_runtime_enable(&pdev->dev);
-	pm_runtime_get_sync(&pdev->dev);
-
-	status = pwmss_submodule_state_change(pdev->dev.parent,
-			PWMSS_ECAPCLK_EN);
-	if (!(status & PWMSS_ECAPCLK_EN_ACK)) {
-		dev_err(&pdev->dev, "PWMSS config space clock enable failed\n");
-		ret = -EINVAL;
-		goto pwmss_clk_failure;
-	}
-
-	pm_runtime_put_sync(&pdev->dev);
 
 	platform_set_drvdata(pdev, pc);
 	return 0;
-
-pwmss_clk_failure:
-	pm_runtime_put_sync(&pdev->dev);
-	pm_runtime_disable(&pdev->dev);
-	pwmchip_remove(&pc->chip);
-	return ret;
 }
 
 static int ecap_pwm_remove(struct platform_device *pdev)
 {
 	struct ecap_pwm_chip *pc = platform_get_drvdata(pdev);
 
-	pm_runtime_get_sync(&pdev->dev);
-	/*
-	 * Due to hardware misbehaviour, acknowledge of the stop_req
-	 * is missing. Hence checking of the status bit skipped.
-	 */
-	pwmss_submodule_state_change(pdev->dev.parent, PWMSS_ECAPCLK_STOP_REQ);
-	pm_runtime_put_sync(&pdev->dev);
-
 	pm_runtime_disable(&pdev->dev);
 	return pwmchip_remove(&pc->chip);
 }
diff --git a/drivers/pwm/pwm-tiehrpwm.c b/drivers/pwm/pwm-tiehrpwm.c
index 6a41e66..e09b1f0 100644
--- a/drivers/pwm/pwm-tiehrpwm.c
+++ b/drivers/pwm/pwm-tiehrpwm.c
@@ -27,8 +27,6 @@
 #include <linux/pm_runtime.h>
 #include <linux/of_device.h>
 
-#include "pwm-tipwmss.h"
-
 /* EHRPWM registers and bits definitions */
 
 /* Time base module registers */
@@ -437,7 +435,6 @@ static int ehrpwm_pwm_probe(struct platform_device *pdev)
 	struct resource *r;
 	struct clk *clk;
 	struct ehrpwm_pwm_chip *pc;
-	u16 status;
 
 	pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL);
 	if (!pc)
@@ -487,27 +484,9 @@ static int ehrpwm_pwm_probe(struct platform_device *pdev)
 	}
 
 	pm_runtime_enable(&pdev->dev);
-	pm_runtime_get_sync(&pdev->dev);
-
-	status = pwmss_submodule_state_change(pdev->dev.parent,
-			PWMSS_EPWMCLK_EN);
-	if (!(status & PWMSS_EPWMCLK_EN_ACK)) {
-		dev_err(&pdev->dev, "PWMSS config space clock enable failed\n");
-		ret = -EINVAL;
-		goto pwmss_clk_failure;
-	}
-
-	pm_runtime_put_sync(&pdev->dev);
 
 	platform_set_drvdata(pdev, pc);
 	return 0;
-
-pwmss_clk_failure:
-	pm_runtime_put_sync(&pdev->dev);
-	pm_runtime_disable(&pdev->dev);
-	pwmchip_remove(&pc->chip);
-	clk_unprepare(pc->tbclk);
-	return ret;
 }
 
 static int ehrpwm_pwm_remove(struct platform_device *pdev)
@@ -516,14 +495,6 @@ static int ehrpwm_pwm_remove(struct platform_device *pdev)
 
 	clk_unprepare(pc->tbclk);
 
-	pm_runtime_get_sync(&pdev->dev);
-	/*
-	 * Due to hardware misbehaviour, acknowledge of the stop_req
-	 * is missing. Hence checking of the status bit skipped.
-	 */
-	pwmss_submodule_state_change(pdev->dev.parent, PWMSS_EPWMCLK_STOP_REQ);
-	pm_runtime_put_sync(&pdev->dev);
-
 	pm_runtime_put_sync(&pdev->dev);
 	pm_runtime_disable(&pdev->dev);
 	return pwmchip_remove(&pc->chip);
diff --git a/drivers/pwm/pwm-tipwmss.c b/drivers/pwm/pwm-tipwmss.c
index 5cf65a1..829f499 100644
--- a/drivers/pwm/pwm-tipwmss.c
+++ b/drivers/pwm/pwm-tipwmss.c
@@ -22,32 +22,6 @@
 #include <linux/pm_runtime.h>
 #include <linux/of_device.h>
 
-#include "pwm-tipwmss.h"
-
-#define PWMSS_CLKCONFIG		0x8	/* Clock gating reg */
-#define PWMSS_CLKSTATUS		0xc	/* Clock gating status reg */
-
-struct pwmss_info {
-	void __iomem	*mmio_base;
-	struct mutex	pwmss_lock;
-	u16		pwmss_clkconfig;
-};
-
-u16 pwmss_submodule_state_change(struct device *dev, int set)
-{
-	struct pwmss_info *info = dev_get_drvdata(dev);
-	u16 val;
-
-	mutex_lock(&info->pwmss_lock);
-	val = readw(info->mmio_base + PWMSS_CLKCONFIG);
-	val |= set;
-	writew(val , info->mmio_base + PWMSS_CLKCONFIG);
-	mutex_unlock(&info->pwmss_lock);
-
-	return readw(info->mmio_base + PWMSS_CLKSTATUS);
-}
-EXPORT_SYMBOL(pwmss_submodule_state_change);
-
 static const struct of_device_id pwmss_of_match[] = {
 	{ .compatible	= "ti,am33xx-pwmss" },
 	{},
@@ -57,24 +31,10 @@ MODULE_DEVICE_TABLE(of, pwmss_of_match);
 static int pwmss_probe(struct platform_device *pdev)
 {
 	int ret;
-	struct resource *r;
-	struct pwmss_info *info;
 	struct device_node *node = pdev->dev.of_node;
 
-	info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
-	if (!info)
-		return -ENOMEM;
-
-	mutex_init(&info->pwmss_lock);
-
-	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	info->mmio_base = devm_ioremap_resource(&pdev->dev, r);
-	if (IS_ERR(info->mmio_base))
-		return PTR_ERR(info->mmio_base);
-
 	pm_runtime_enable(&pdev->dev);
 	pm_runtime_get_sync(&pdev->dev);
-	platform_set_drvdata(pdev, info);
 
 	/* Populate all the child nodes here... */
 	ret = of_platform_populate(node, NULL, NULL, &pdev->dev);
@@ -86,30 +46,21 @@ static int pwmss_probe(struct platform_device *pdev)
 
 static int pwmss_remove(struct platform_device *pdev)
 {
-	struct pwmss_info *info = platform_get_drvdata(pdev);
-
 	pm_runtime_put_sync(&pdev->dev);
 	pm_runtime_disable(&pdev->dev);
-	mutex_destroy(&info->pwmss_lock);
 	return 0;
 }
 
 #ifdef CONFIG_PM_SLEEP
 static int pwmss_suspend(struct device *dev)
 {
-	struct pwmss_info *info = dev_get_drvdata(dev);
-
-	info->pwmss_clkconfig = readw(info->mmio_base + PWMSS_CLKCONFIG);
 	pm_runtime_put_sync(dev);
 	return 0;
 }
 
 static int pwmss_resume(struct device *dev)
 {
-	struct pwmss_info *info = dev_get_drvdata(dev);
-
 	pm_runtime_get_sync(dev);
-	writew(info->pwmss_clkconfig, info->mmio_base + PWMSS_CLKCONFIG);
 	return 0;
 }
 #endif
diff --git a/drivers/pwm/pwm-tipwmss.h b/drivers/pwm/pwm-tipwmss.h
deleted file mode 100644
index 10ad804..0000000
--- a/drivers/pwm/pwm-tipwmss.h
+++ /dev/null
@@ -1,39 +0,0 @@
-/*
- * TI PWM Subsystem driver
- *
- * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com/
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- */
-
-#ifndef __TIPWMSS_H
-#define __TIPWMSS_H
-
-/* PWM substem clock gating */
-#define PWMSS_ECAPCLK_EN	BIT(0)
-#define PWMSS_ECAPCLK_STOP_REQ	BIT(1)
-#define PWMSS_EPWMCLK_EN	BIT(8)
-#define PWMSS_EPWMCLK_STOP_REQ	BIT(9)
-
-#define PWMSS_ECAPCLK_EN_ACK	BIT(0)
-#define PWMSS_EPWMCLK_EN_ACK	BIT(8)
-
-#ifdef CONFIG_PWM_TIPWMSS
-extern u16 pwmss_submodule_state_change(struct device *dev, int set);
-#else
-static inline u16 pwmss_submodule_state_change(struct device *dev, int set)
-{
-	/* return success status value */
-	return 0xFFFF;
-}
-#endif
-#endif	/* __TIPWMSS_H */
-- 
2.7.0