mfd: do tcb6393xb state restore on resume only if requested

As requested by Ian make state restore only if it's requested
by platform data: some platforms do correctly save the state of
the chip during suspend/resume, but some (like tosa) incorrectly
power off the chip at suspend, so the driver supports restoring
some bits of the tc6393xb state (not full, merely enough to support
resume on tosa). With this patch this code is disabled by default.
Signed-off-by: Dmitry Baryshkov <dbaryshkov@gmail.com>
Acked-by: Ian Molton <spyro@f2s.com>
Signed-off-by: Samuel Ortiz <sameo@openedhand.com>

arch/arm/mach-pxa/tosa.c

@@ -746,6 +746,8 @@ static struct tc6393xb_platform_data tosa_tc6393xb_data = {
 	.resume		= tosa_tc6393xb_resume,
 
 	.nand_data	= &tosa_tc6393xb_nand_config,
+
+	.resume_restore = 1,
 };
 
 

drivers/mfd/tc6393xb.c

@@ -369,41 +369,12 @@ static void tc6393xb_detach_irq(struct platform_device *dev)
 
 /*--------------------------------------------------------------------------*/
 
-static int tc6393xb_hw_init(struct platform_device *dev)
-{
-	struct tc6393xb_platform_data *tcpd = dev->dev.platform_data;
-	struct tc6393xb *tc6393xb = platform_get_drvdata(dev);
-	int i;
-
-	iowrite8(tc6393xb->suspend_state.fer,	tc6393xb->scr + SCR_FER);
-	iowrite16(tcpd->scr_pll2cr,		tc6393xb->scr + SCR_PLL2CR);
-	iowrite16(tc6393xb->suspend_state.ccr,	tc6393xb->scr + SCR_CCR);
-	iowrite16(SCR_MCR_RDY_OPENDRAIN | SCR_MCR_RDY_UNK | SCR_MCR_RDY_EN |
-		  SCR_MCR_INT_OPENDRAIN | SCR_MCR_INT_UNK | SCR_MCR_INT_EN |
-		  BIT(15),			tc6393xb->scr + SCR_MCR);
-	iowrite16(tcpd->scr_gper,		tc6393xb->scr + SCR_GPER);
-	iowrite8(0,				tc6393xb->scr + SCR_IRR);
-	iowrite8(0xbf,				tc6393xb->scr + SCR_IMR);
-
-	for (i = 0; i < 3; i++) {
-		iowrite8(tc6393xb->suspend_state.gpo_dsr[i],
-					tc6393xb->scr + SCR_GPO_DSR(i));
-		iowrite8(tc6393xb->suspend_state.gpo_doecr[i],
-					tc6393xb->scr + SCR_GPO_DOECR(i));
-		iowrite8(tc6393xb->suspend_state.gpi_bcr[i],
-					tc6393xb->scr + SCR_GPI_BCR(i));
-	}
-
-	return 0;
-}
-
 static int __devinit tc6393xb_probe(struct platform_device *dev)
 {
 	struct tc6393xb_platform_data *tcpd = dev->dev.platform_data;
 	struct tc6393xb *tc6393xb;
 	struct resource *iomem, *rscr;
 	int ret, temp;
-	int i;
 
 	iomem = platform_get_resource(dev, IORESOURCE_MEM, 0);
 	if (!iomem)
@@ -458,14 +429,16 @@ static int __devinit tc6393xb_probe(struct platform_device *dev)
 	if (ret)
 		goto err_enable;
 
-	tc6393xb->suspend_state.fer = 0;
-
-	tc6393xb->suspend_state.ccr = SCR_CCR_UNK1 |
-					SCR_CCR_HCLK_48;
-
-	ret = tc6393xb_hw_init(dev);
-	if (ret)
-		goto err_hw_init;
+	iowrite8(0,				tc6393xb->scr + SCR_FER);
+	iowrite16(tcpd->scr_pll2cr,		tc6393xb->scr + SCR_PLL2CR);
+	iowrite16(SCR_CCR_UNK1 | SCR_CCR_HCLK_48,
+						tc6393xb->scr + SCR_CCR);
+	iowrite16(SCR_MCR_RDY_OPENDRAIN | SCR_MCR_RDY_UNK | SCR_MCR_RDY_EN |
+		  SCR_MCR_INT_OPENDRAIN | SCR_MCR_INT_UNK | SCR_MCR_INT_EN |
+		  BIT(15),			tc6393xb->scr + SCR_MCR);
+	iowrite16(tcpd->scr_gper,		tc6393xb->scr + SCR_GPER);
+	iowrite8(0,				tc6393xb->scr + SCR_IRR);
+	iowrite8(0xbf,				tc6393xb->scr + SCR_IMR);
 
 	printk(KERN_INFO "Toshiba tc6393xb revision %d at 0x%08lx, irq %d\n",
 			tmio_ioread8(tc6393xb->scr + SCR_REVID),
@@ -514,7 +487,6 @@ static int __devinit tc6393xb_probe(struct platform_device *dev)
 err_gpio_add:
 	if (tc6393xb->gpio.base != -1)
 		temp = gpiochip_remove(&tc6393xb->gpio);
-err_hw_init:
 	tcpd->disable(dev);
 err_clk_enable:
 	clk_disable(tc6393xb->clk);
@@ -592,15 +564,37 @@ static int tc6393xb_resume(struct platform_device *dev)
 	struct tc6393xb_platform_data *tcpd = dev->dev.platform_data;
 	struct tc6393xb *tc6393xb = platform_get_drvdata(dev);
 	int ret;
+	int i;
 
 	clk_enable(tc6393xb->clk);
 
 	ret = tcpd->resume(dev);
-
 	if (ret)
 		return ret;
 
-	return tc6393xb_hw_init(dev);
+	if (!tcpd->resume_restore)
+		return 0;
+
+	iowrite8(tc6393xb->suspend_state.fer,	tc6393xb->scr + SCR_FER);
+	iowrite16(tcpd->scr_pll2cr,		tc6393xb->scr + SCR_PLL2CR);
+	iowrite16(tc6393xb->suspend_state.ccr,	tc6393xb->scr + SCR_CCR);
+	iowrite16(SCR_MCR_RDY_OPENDRAIN | SCR_MCR_RDY_UNK | SCR_MCR_RDY_EN |
+		  SCR_MCR_INT_OPENDRAIN | SCR_MCR_INT_UNK | SCR_MCR_INT_EN |
+		  BIT(15),			tc6393xb->scr + SCR_MCR);
+	iowrite16(tcpd->scr_gper,		tc6393xb->scr + SCR_GPER);
+	iowrite8(0,				tc6393xb->scr + SCR_IRR);
+	iowrite8(0xbf,				tc6393xb->scr + SCR_IMR);
+
+	for (i = 0; i < 3; i++) {
+		iowrite8(tc6393xb->suspend_state.gpo_dsr[i],
+					tc6393xb->scr + SCR_GPO_DSR(i));
+		iowrite8(tc6393xb->suspend_state.gpo_doecr[i],
+					tc6393xb->scr + SCR_GPO_DOECR(i));
+		iowrite8(tc6393xb->suspend_state.gpi_bcr[i],
+					tc6393xb->scr + SCR_GPI_BCR(i));
+	}
+
+	return 0;
 }
 #else
 #define tc6393xb_suspend NULL

include/linux/mfd/tc6393xb.h

@@ -33,6 +33,10 @@ struct tc6393xb_platform_data {
 	void	(*teardown)(struct platform_device *dev);
 
 	struct tmio_nand_data	*nand_data;
+
+	unsigned resume_restore : 1; /* make special actions
+					to preserve the state
+					on suspend/resume */
 };
 
 /*