usb: musb: Add context save and restore support

Adding support for MUSB register save and restore during system
suspend and resume.

Changes:
        - Added musb_save/restore_context() functions
        - Added platform specific musb_platform_save/restore_context()
          to handle platform specific jobs.
        - Maintaining BlackFin compatibility by adding read/write
          functions for registers which are not available in BlackFin

Tested system suspend and resume on OMAP3EVM board.
Signed-off-by: Anand Gadiyar <gadiyar@ti.com>
Signed-off-by: Ajay Kumar Gupta <ajay.gupta@ti.com>
Signed-off-by: Felipe Balbi <felipe.balbi@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/musb/musb_core.c

@@ -2167,6 +2167,148 @@ static int __exit musb_remove(struct platform_device *pdev)
 
 #ifdef	CONFIG_PM
 
+static struct musb_context_registers musb_context;
+
+void musb_save_context(struct musb *musb)
+{
+	int i;
+	void __iomem *musb_base = musb->mregs;
+
+	if (is_host_enabled(musb)) {
+		musb_context.frame = musb_readw(musb_base, MUSB_FRAME);
+		musb_context.testmode = musb_readb(musb_base, MUSB_TESTMODE);
+	}
+	musb_context.power = musb_readb(musb_base, MUSB_POWER);
+	musb_context.intrtxe = musb_readw(musb_base, MUSB_INTRTXE);
+	musb_context.intrrxe = musb_readw(musb_base, MUSB_INTRRXE);
+	musb_context.intrusbe = musb_readb(musb_base, MUSB_INTRUSBE);
+	musb_context.index = musb_readb(musb_base, MUSB_INDEX);
+	musb_context.devctl = musb_readb(musb_base, MUSB_DEVCTL);
+
+	for (i = 0; i < MUSB_C_NUM_EPS; ++i) {
+		musb_writeb(musb_base, MUSB_INDEX, i);
+		musb_context.index_regs[i].txmaxp =
+			musb_readw(musb_base, 0x10 + MUSB_TXMAXP);
+		musb_context.index_regs[i].txcsr =
+			musb_readw(musb_base, 0x10 + MUSB_TXCSR);
+		musb_context.index_regs[i].rxmaxp =
+			musb_readw(musb_base, 0x10 + MUSB_RXMAXP);
+		musb_context.index_regs[i].rxcsr =
+			musb_readw(musb_base, 0x10 + MUSB_RXCSR);
+
+		if (musb->dyn_fifo) {
+			musb_context.index_regs[i].txfifoadd =
+					musb_read_txfifoadd(musb_base);
+			musb_context.index_regs[i].rxfifoadd =
+					musb_read_rxfifoadd(musb_base);
+			musb_context.index_regs[i].txfifosz =
+					musb_read_txfifosz(musb_base);
+			musb_context.index_regs[i].rxfifosz =
+					musb_read_rxfifosz(musb_base);
+		}
+		if (is_host_enabled(musb)) {
+			musb_context.index_regs[i].txtype =
+				musb_readb(musb_base, 0x10 + MUSB_TXTYPE);
+			musb_context.index_regs[i].txinterval =
+				musb_readb(musb_base, 0x10 + MUSB_TXINTERVAL);
+			musb_context.index_regs[i].rxtype =
+				musb_readb(musb_base, 0x10 + MUSB_RXTYPE);
+			musb_context.index_regs[i].rxinterval =
+				musb_readb(musb_base, 0x10 + MUSB_RXINTERVAL);
+
+			musb_context.index_regs[i].txfunaddr =
+				musb_read_txfunaddr(musb_base, i);
+			musb_context.index_regs[i].txhubaddr =
+				musb_read_txhubaddr(musb_base, i);
+			musb_context.index_regs[i].txhubport =
+				musb_read_txhubport(musb_base, i);
+
+			musb_context.index_regs[i].rxfunaddr =
+				musb_read_rxfunaddr(musb_base, i);
+			musb_context.index_regs[i].rxhubaddr =
+				musb_read_rxhubaddr(musb_base, i);
+			musb_context.index_regs[i].rxhubport =
+				musb_read_rxhubport(musb_base, i);
+		}
+	}
+
+	musb_writeb(musb_base, MUSB_INDEX, musb_context.index);
+
+	musb_platform_save_context(&musb_context);
+}
+
+void musb_restore_context(struct musb *musb)
+{
+	int i;
+	void __iomem *musb_base = musb->mregs;
+	void __iomem *ep_target_regs;
+
+	musb_platform_restore_context(&musb_context);
+
+	if (is_host_enabled(musb)) {
+		musb_writew(musb_base, MUSB_FRAME, musb_context.frame);
+		musb_writeb(musb_base, MUSB_TESTMODE, musb_context.testmode);
+	}
+	musb_writeb(musb_base, MUSB_POWER, musb_context.power);
+	musb_writew(musb_base, MUSB_INTRTXE, musb_context.intrtxe);
+	musb_writew(musb_base, MUSB_INTRRXE, musb_context.intrrxe);
+	musb_writeb(musb_base, MUSB_INTRUSBE, musb_context.intrusbe);
+	musb_writeb(musb_base, MUSB_DEVCTL, musb_context.devctl);
+
+	for (i = 0; i < MUSB_C_NUM_EPS; ++i) {
+		musb_writeb(musb_base, MUSB_INDEX, i);
+		musb_writew(musb_base, 0x10 + MUSB_TXMAXP,
+			musb_context.index_regs[i].txmaxp);
+		musb_writew(musb_base, 0x10 + MUSB_TXCSR,
+			musb_context.index_regs[i].txcsr);
+		musb_writew(musb_base, 0x10 + MUSB_RXMAXP,
+			musb_context.index_regs[i].rxmaxp);
+		musb_writew(musb_base, 0x10 + MUSB_RXCSR,
+			musb_context.index_regs[i].rxcsr);
+
+		if (musb->dyn_fifo) {
+			musb_write_txfifosz(musb_base,
+				musb_context.index_regs[i].txfifosz);
+			musb_write_rxfifosz(musb_base,
+				musb_context.index_regs[i].rxfifosz);
+			musb_write_txfifoadd(musb_base,
+				musb_context.index_regs[i].txfifoadd);
+			musb_write_rxfifoadd(musb_base,
+				musb_context.index_regs[i].rxfifoadd);
+		}
+
+		if (is_host_enabled(musb)) {
+			musb_writeb(musb_base, 0x10 + MUSB_TXTYPE,
+				musb_context.index_regs[i].txtype);
+			musb_writeb(musb_base, 0x10 + MUSB_TXINTERVAL,
+				musb_context.index_regs[i].txinterval);
+			musb_writeb(musb_base, 0x10 + MUSB_RXTYPE,
+				musb_context.index_regs[i].rxtype);
+			musb_writeb(musb_base, 0x10 + MUSB_RXINTERVAL,
+
+			musb_context.index_regs[i].rxinterval);
+			musb_write_txfunaddr(musb_base, i,
+				musb_context.index_regs[i].txfunaddr);
+			musb_write_txhubaddr(musb_base, i,
+				musb_context.index_regs[i].txhubaddr);
+			musb_write_txhubport(musb_base, i,
+				musb_context.index_regs[i].txhubport);
+
+			ep_target_regs =
+				musb_read_target_reg_base(i, musb_base);
+
+			musb_write_rxfunaddr(ep_target_regs,
+				musb_context.index_regs[i].rxfunaddr);
+			musb_write_rxhubaddr(ep_target_regs,
+				musb_context.index_regs[i].rxhubaddr);
+			musb_write_rxhubport(ep_target_regs,
+				musb_context.index_regs[i].rxhubport);
+		}
+	}
+
+	musb_writeb(musb_base, MUSB_INDEX, musb_context.index);
+}
+
 static int musb_suspend(struct device *dev)
 {
 	struct platform_device *pdev = to_platform_device(dev);
@@ -2188,6 +2330,8 @@ static int musb_suspend(struct device *dev)
 		 */
 	}
 
+	musb_save_context(musb);
+
 	if (musb->set_clock)
 		musb->set_clock(musb->clock, 0);
 	else
@@ -2209,6 +2353,8 @@ static int musb_resume_noirq(struct device *dev)
 	else
 		clk_enable(musb->clock);
 
+	musb_restore_context(musb);
+
 	/* for static cmos like DaVinci, register values were preserved
 	 * unless for some reason the whole soc powered down or the USB
 	 * module got reset through the PSC (vs just being disabled).

drivers/usb/musb/musb_core.h

@@ -454,6 +454,45 @@ struct musb {
 #endif
 };
 
+#ifdef CONFIG_PM
+struct musb_csr_regs {
+	/* FIFO registers */
+	u16 txmaxp, txcsr, rxmaxp, rxcsr;
+	u16 rxfifoadd, txfifoadd;
+	u8 txtype, txinterval, rxtype, rxinterval;
+	u8 rxfifosz, txfifosz;
+	u8 txfunaddr, txhubaddr, txhubport;
+	u8 rxfunaddr, rxhubaddr, rxhubport;
+};
+
+struct musb_context_registers {
+
+#if defined(CONFIG_ARCH_OMAP34XX) || defined(CONFIG_ARCH_OMAP2430)
+	u32 otg_sysconfig, otg_forcestandby;
+#endif
+	u8 power;
+	u16 intrtxe, intrrxe;
+	u8 intrusbe;
+	u16 frame;
+	u8 index, testmode;
+
+	u8 devctl, misc;
+
+	struct musb_csr_regs index_regs[MUSB_C_NUM_EPS];
+};
+
+#if defined(CONFIG_ARCH_OMAP34XX) || defined(CONFIG_ARCH_OMAP2430)
+extern void musb_platform_save_context(struct musb_context_registers
+		*musb_context);
+extern void musb_platform_restore_context(struct musb_context_registers
+		*musb_context);
+#else
+#define musb_platform_save_context(x)		do {} while (0)
+#define musb_platform_restore_context(x)	do {} while (0)
+#endif
+
+#endif
+
 static inline void musb_set_vbus(struct musb *musb, int is_on)
 {
 	musb->board_set_vbus(musb, is_on);

drivers/usb/musb/musb_regs.h

@@ -326,6 +326,26 @@ static inline void  musb_write_rxfifoadd(void __iomem *mbase, u16 c_off)
 	musb_writew(mbase, MUSB_RXFIFOADD, c_off);
 }
 
+static inline u8 musb_read_txfifosz(void __iomem *mbase)
+{
+	return musb_readb(mbase, MUSB_TXFIFOSZ);
+}
+
+static inline u16 musb_read_txfifoadd(void __iomem *mbase)
+{
+	return musb_readw(mbase, MUSB_TXFIFOADD);
+}
+
+static inline u8 musb_read_rxfifosz(void __iomem *mbase)
+{
+	return musb_readb(mbase, MUSB_RXFIFOSZ);
+}
+
+static inline u16  musb_read_rxfifoadd(void __iomem *mbase)
+{
+	return musb_readw(mbase, MUSB_RXFIFOADD);
+}
+
 static inline u8 musb_read_configdata(void __iomem *mbase)
 {
 	musb_writeb(mbase, MUSB_INDEX, 0);
@@ -381,6 +401,36 @@ static inline void  musb_write_txhubport(void __iomem *mbase, u8 epnum,
 			qh_h_port_reg);
 }
 
+static inline u8 musb_read_rxfunaddr(void __iomem *mbase, u8 epnum)
+{
+	return musb_readb(mbase, MUSB_BUSCTL_OFFSET(epnum, MUSB_RXFUNCADDR));
+}
+
+static inline u8 musb_read_rxhubaddr(void __iomem *mbase, u8 epnum)
+{
+	return musb_readb(mbase, MUSB_BUSCTL_OFFSET(epnum, MUSB_RXHUBADDR));
+}
+
+static inline u8 musb_read_rxhubport(void __iomem *mbase, u8 epnum)
+{
+	return musb_readb(mbase, MUSB_BUSCTL_OFFSET(epnum, MUSB_RXHUBPORT));
+}
+
+static inline u8  musb_read_txfunaddr(void __iomem *mbase, u8 epnum)
+{
+	return musb_readb(mbase, MUSB_BUSCTL_OFFSET(epnum, MUSB_TXFUNCADDR));
+}
+
+static inline u8  musb_read_txhubaddr(void __iomem *mbase, u8 epnum)
+{
+	return musb_readb(mbase, MUSB_BUSCTL_OFFSET(epnum, MUSB_TXHUBADDR));
+}
+
+static inline u8  musb_read_txhubport(void __iomem *mbase, u8 epnum)
+{
+	return musb_readb(mbase, MUSB_BUSCTL_OFFSET(epnum, MUSB_TXHUBPORT));
+}
+
 #else /* CONFIG_BLACKFIN */
 
 #define USB_BASE		USB_FADDR
@@ -460,6 +510,22 @@ static inline void  musb_write_rxfifoadd(void __iomem *mbase, u16 c_off)
 {
 }
 
+static inline u8 musb_read_txfifosz(void __iomem *mbase)
+{
+}
+
+static inline u16 musb_read_txfifoadd(void __iomem *mbase)
+{
+}
+
+static inline u8 musb_read_rxfifosz(void __iomem *mbase)
+{
+}
+
+static inline u16  musb_read_rxfifoadd(void __iomem *mbase)
+{
+}
+
 static inline u8 musb_read_configdata(void __iomem *mbase)
 {
 	return 0;
@@ -505,6 +571,30 @@ static inline void  musb_write_txhubport(void __iomem *mbase, u8 epnum,
 {
 }
 
+static inline u8 musb_read_rxfunaddr(void __iomem *mbase, u8 epnum)
+{
+}
+
+static inline u8 musb_read_rxhubaddr(void __iomem *mbase, u8 epnum)
+{
+}
+
+static inline u8 musb_read_rxhubport(void __iomem *mbase, u8 epnum)
+{
+}
+
+static inline u8  musb_read_txfunaddr(void __iomem *mbase, u8 epnum)
+{
+}
+
+static inline u8  musb_read_txhubaddr(void __iomem *mbase, u8 epnum)
+{
+}
+
+static inline void  musb_read_txhubport(void __iomem *mbase, u8 epnum)
+{
+}
+
 #endif /* CONFIG_BLACKFIN */
 
 #endif	/* __MUSB_REGS_H__ */

drivers/usb/musb/omap2430.c

@@ -255,6 +255,22 @@ int __init musb_platform_init(struct musb *musb)
 	return 0;
 }
 
+#ifdef CONFIG_PM
+void musb_platform_save_context(struct musb_context_registers
+		*musb_context)
+{
+	musb_context->otg_sysconfig = omap_readl(OTG_SYSCONFIG);
+	musb_context->otg_forcestandby = omap_readl(OTG_FORCESTDBY);
+}
+
+void musb_platform_restore_context(struct musb_context_registers
+		*musb_context)
+{
+	omap_writel(musb_context->otg_sysconfig, OTG_SYSCONFIG);
+	omap_writel(musb_context->otg_forcestandby, OTG_FORCESTDBY);
+}
+#endif
+
 int musb_platform_suspend(struct musb *musb)
 {
 	u32 l;