powerpc/85xx: Add lbc suspend support for PM

Power supply for LBC registers is off when system go to deep-sleep state.
We save the values of registers before suspend and restore to registers
after resume.

We removed the last two reservation arrays from struct fsl_lbc_regs for
allocating less memory and minimizing the memcpy size.

Signed-off-by: Jiang Yutang <[e-mail]>
Signed-off-by: Jia Hongtao <[e-mail]>
Signed-off-by: Li Yang <[e-mail]>
Signed-off-by: Kumar Gala <[e-mail]>

arch/powerpc/include/asm/fsl_lbc.h

···
 #define FPAR_LP_CI_SHIFT      0
 	__be32 fbcr;            /**< Flash Byte Count Register */
 #define FBCR_BC      0x00000FFF
-	u8 res11[0x8];
-	u8 res8[0xF00];
 };
 
 /*
···
 
 	/* status read from LTESR by irq handler */
 	unsigned int			irq_status;
+
+#ifdef CONFIG_SUSPEND
+	/* save regs when system go to deep-sleep */
+	struct fsl_lbc_regs		*saved_regs;
+#endif
 };
 
 extern int fsl_upm_run_pattern(struct fsl_upm *upm, void __iomem *io_base,

arch/powerpc/sysdev/fsl_lbc.c

···
 	return ret;
 }
 
+#ifdef CONFIG_SUSPEND
+
+/* save lbc registers */
+static int fsl_lbc_suspend(struct platform_device *pdev, pm_message_t state)
+{
+	struct fsl_lbc_ctrl *ctrl = dev_get_drvdata(&pdev->dev);
+	struct fsl_lbc_regs __iomem *lbc = ctrl->regs;
+
+	ctrl->saved_regs = kmalloc(sizeof(struct fsl_lbc_regs), GFP_KERNEL);
+	if (!ctrl->saved_regs)
+		return -ENOMEM;
+
+	_memcpy_fromio(ctrl->saved_regs, lbc, sizeof(struct fsl_lbc_regs));
+	return 0;
+}
+
+/* restore lbc registers */
+static int fsl_lbc_resume(struct platform_device *pdev)
+{
+	struct fsl_lbc_ctrl *ctrl = dev_get_drvdata(&pdev->dev);
+	struct fsl_lbc_regs __iomem *lbc = ctrl->regs;
+
+	if (ctrl->saved_regs) {
+		_memcpy_toio(lbc, ctrl->saved_regs,
+				sizeof(struct fsl_lbc_regs));
+		kfree(ctrl->saved_regs);
+		ctrl->saved_regs = NULL;
+	}
+	return 0;
+}
+#endif /* CONFIG_SUSPEND */
+
 static const struct of_device_id fsl_lbc_match[] = {
 	{ .compatible = "fsl,elbc", },
 	{ .compatible = "fsl,pq3-localbus", },
···
 		.of_match_table = fsl_lbc_match,
 	},
 	.probe = fsl_lbc_ctrl_probe,
+#ifdef CONFIG_SUSPEND
+	.suspend     = fsl_lbc_suspend,
+	.resume      = fsl_lbc_resume,
+#endif
 };
 
 static int __init fsl_lbc_init(void)