Blackfin arch: rewrite our reboot code in C

rewrite our reboot code in C rather than assembly to be like
other architectures and to allow board maintainers to define
custom behavior

Signed-off-by: Mike Frysinger <michael.frysinger@analog.com>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>

arch/blackfin/kernel/Makefile

@@ -7,7 +7,7 @@ extra-y := init_task.o vmlinux.lds
 obj-y := \
 	entry.o process.o bfin_ksyms.o ptrace.o setup.o signal.o \
 	sys_bfin.o time.o traps.o irqchip.o dma-mapping.o flat.o \
-	fixed_code.o cplbinit.o cacheinit.o
+	fixed_code.o cplbinit.o cacheinit.o reboot.o
 
 obj-$(CONFIG_BF53x)		     += bfin_gpio.o
 obj-$(CONFIG_BF561)		     += bfin_gpio.o

arch/blackfin/kernel/bfin_gpio.c

@@ -80,6 +80,7 @@
 *  GPIO_47      PH15        PF47
 */
 
+#include <linux/delay.h>
 #include <linux/module.h>
 #include <linux/err.h>
 #include <asm/blackfin.h>
@@ -888,3 +889,20 @@ void gpio_direction_output(unsigned short gpio)
 	local_irq_restore(flags);
 }
 EXPORT_SYMBOL(gpio_direction_output);
+
+/* If we are booting from SPI and our board lacks a strong enough pull up,
+ * the core can reset and execute the bootrom faster than the resistor can
+ * pull the signal logically high.  To work around this (common) error in
+ * board design, we explicitly set the pin back to GPIO mode, force /CS
+ * high, and wait for the electrons to do their thing.
+ *
+ * This function only makes sense to be called from reset code, but it
+ * lives here as we need to force all the GPIO states w/out going through
+ * BUG() checks and such.
+ */
+void bfin_gpio_reset_spi0_ssel1(void)
+{
+	port_setup(P_SPI0_SSEL1, GPIO_USAGE);
+	gpio_bankb[gpio_bank(P_SPI0_SSEL1)]->data_set = gpio_bit(P_SPI0_SSEL1);
+	udelay(1);
+}

arch/blackfin/kernel/process.c

@@ -134,31 +134,6 @@ void cpu_idle(void)
 	}
 }
 
-void machine_restart(char *__unused)
-{
-#if defined(CONFIG_BFIN_ICACHE)
-	bfin_write_IMEM_CONTROL(0x01);
-	SSYNC();
-#endif
-	bfin_reset();
-	/* Dont do anything till the reset occurs */
-	while (1) {
-		SSYNC();
-	}
-}
-
-void machine_halt(void)
-{
-	for (;;)
-		asm volatile ("idle");
-}
-
-void machine_power_off(void)
-{
-	for (;;)
-		asm volatile ("idle");
-}
-
 void show_regs(struct pt_regs *regs)
 {
 	printk(KERN_NOTICE "\n");

arch/blackfin/mach-bf533/head.S

@@ -459,66 +459,6 @@ ENTRY(_start_dma_code)
 ENDPROC(_start_dma_code)
 #endif /* CONFIG_BFIN_KERNEL_CLOCK */
 
-ENTRY(_bfin_reset)
-	/* No more interrupts to be handled*/
-	CLI R6;
-	SSYNC;
-
-#if defined(CONFIG_BFIN_SHARED_FLASH_ENET)
-	p0.h = hi(FIO_INEN);
-	p0.l = lo(FIO_INEN);
-	r0.l = ~(1 << CONFIG_ENET_FLASH_PIN);
-	w[p0] = r0.l;
-
-	p0.h = hi(FIO_DIR);
-	p0.l = lo(FIO_DIR);
-	r0.l = (1 << CONFIG_ENET_FLASH_PIN);
-	w[p0] = r0.l;
-
-	p0.h = hi(FIO_FLAG_C);
-	p0.l = lo(FIO_FLAG_C);
-	r0.l = (1 << CONFIG_ENET_FLASH_PIN);
-	w[p0] = r0.l;
-#endif
-
-	/* Clear the IMASK register */
-	p0.h = hi(IMASK);
-	p0.l = lo(IMASK);
-	r0 = 0x0;
-	[p0] = r0;
-
-	/* Clear the ILAT register */
-	p0.h = hi(ILAT);
-	p0.l = lo(ILAT);
-	r0 = [p0];
-	[p0] = r0;
-	SSYNC;
-
-	/* make sure SYSCR is set to use BMODE */
-	P0.h = hi(SYSCR);
-	P0.l = lo(SYSCR);
-	R0.l = 0x0;
-	W[P0] = R0.l;
-	SSYNC;
-
-	/* issue a system soft reset */
-	P1.h = hi(SWRST);
-	P1.l = lo(SWRST);
-	R1.l = 0x0007;
-	W[P1] = R1;
-	SSYNC;
-
-	/* clear system soft reset */
-	R0.l = 0x0000;
-	W[P0] = R0;
-	SSYNC;
-
-	/* issue core reset */
-	raise 1;
-
-	RTS;
-ENDPROC(_bfin_reset)
-
 #if CONFIG_DEBUG_KERNEL_START
 debug_kernel_start_trap:
 	/* Set up a temp stack in L1 - SDRAM might not be working  */

arch/blackfin/mach-bf537/head.S

@@ -478,85 +478,6 @@ ENTRY(_start_dma_code)
 ENDPROC(_start_dma_code)
 #endif /* CONFIG_BFIN_KERNEL_CLOCK */
 
-ENTRY(_bfin_reset)
-	/* No more interrupts to be handled*/
-	CLI R6;
-	SSYNC;
-
-#if defined(CONFIG_MTD_M25P80)
-	/*
-	 * The following code fix the SPI flash reboot issue,
-	 * /CS signal of the chip which is using PF10 return to GPIO mode
-	 */
-	p0.h = hi(PORTF_FER);
-	p0.l = lo(PORTF_FER);
-	r0.l = 0x0000;
-	w[p0] = r0.l;
-	SSYNC;
-
-	/* /CS return to high */
-	p0.h = hi(PORTFIO);
-	p0.l = lo(PORTFIO);
-	r0.l = 0xFFFF;
-	w[p0] = r0.l;
-	SSYNC;
-
-	/* Delay some time, This is necessary */
-	r1.h = 0;
-	r1.l = 0x400;
-	p1   = r1;
-	lsetup (.L_delay_lab1, .L_delay_lab1_end) lc1 = p1;
-.L_delay_lab1:
-	r0.h = 0;
-	r0.l = 0x8000;
-	p0   = r0;
-	lsetup (.L_delay_lab0, .L_delay_lab0_end) lc0 = p0;
-.L_delay_lab0:
-	nop;
-.L_delay_lab0_end:
-	nop;
-.L_delay_lab1_end:
-	nop;
-#endif
-
-	/* Clear the IMASK register */
-	p0.h = hi(IMASK);
-	p0.l = lo(IMASK);
-	r0 = 0x0;
-	[p0] = r0;
-
-	/* Clear the ILAT register */
-	p0.h = hi(ILAT);
-	p0.l = lo(ILAT);
-	r0 = [p0];
-	[p0] = r0;
-	SSYNC;
-
-	/* make sure SYSCR is set to use BMODE */
-	P0.h = hi(SYSCR);
-	P0.l = lo(SYSCR);
-	R0.l = 0x0;
-	W[P0] = R0.l;
-	SSYNC;
-
-	/* issue a system soft reset */
-	P1.h = hi(SWRST);
-	P1.l = lo(SWRST);
-	R1.l = 0x0007;
-	W[P1] = R1;
-	SSYNC;
-
-	/* clear system soft reset */
-	R0.l = 0x0000;
-	W[P0] = R0;
-	SSYNC;
-
-	/* issue core reset */
-	raise 1;
-
-	RTS;
-ENDPROC(_bfin_reset)
-
 .data
 
 /*

arch/blackfin/mach-bf548/head.S

@@ -378,131 +378,6 @@ ENTRY(_start_dma_code)
 	RTS;
 #endif /* CONFIG_BFIN_KERNEL_CLOCK */
 
-ENTRY(_bfin_reset)
-	/* No more interrupts to be handled*/
-	CLI R6;
-	SSYNC;
-
-#if 0 /* Need to determine later if this is here necessary for BF54x */
-#if defined(CONFIG_MTD_M25P80)
-/*
- * The following code fix the SPI flash reboot issue,
- * /CS signal of the chip which is using PF10 return to GPIO mode
- */
-	p0.h = hi(PORTF_FER);
-	p0.l = lo(PORTF_FER);
-	r0.l = 0x0000;
-	w[p0] = r0.l;
-	SSYNC;
-
-/* /CS return to high */
-	p0.h = hi(PORTFIO);
-	p0.l = lo(PORTFIO);
-	r0.l = 0xFFFF;
-	w[p0] = r0.l;
-	SSYNC;
-
-/* Delay some time, This is necessary */
-	r1.h = 0;
-	r1.l = 0x400;
-	p1   = r1;
-	lsetup (_delay_lab1,_delay_lab1_end ) lc1 = p1;
-_delay_lab1:
-	r0.h = 0;
-	r0.l = 0x8000;
-	p0   = r0;
-	lsetup (_delay_lab0,_delay_lab0_end ) lc0 = p0;
-_delay_lab0:
-	nop;
-_delay_lab0_end:
-	nop;
-_delay_lab1_end:
-	nop;
-#endif
-#endif
-
-	/* Clear the bits 13-15 in SWRST if they werent cleared */
-	p0.h = hi(SWRST);
-	p0.l = lo(SWRST);
-	csync;
-	r0.l = w[p0];
-
-	/* Clear the IMASK register */
-	p0.h = hi(IMASK);
-	p0.l = lo(IMASK);
-	r0 = 0x0;
-	[p0] = r0;
-
-	/* Clear the ILAT register */
-	p0.h = hi(ILAT);
-	p0.l = lo(ILAT);
-	r0 = [p0];
-	[p0] = r0;
-	SSYNC;
-
-	/* Disable the WDOG TIMER */
-	p0.h = hi(WDOG_CTL);
-	p0.l = lo(WDOG_CTL);
-	r0.l = 0xAD6;
-	w[p0] = r0.l;
-	SSYNC;
-
-	/* Clear the sticky bit incase it is already set */
-	p0.h = hi(WDOG_CTL);
-	p0.l = lo(WDOG_CTL);
-	r0.l = 0x8AD6;
-	w[p0] = r0.l;
-	SSYNC;
-
-	/* Program the count value */
-	R0.l = 0x100;
-	R0.h = 0x0;
-	P0.h = hi(WDOG_CNT);
-	P0.l = lo(WDOG_CNT);
-	[P0] = R0;
-	SSYNC;
-
-	/* Program WDOG_STAT if necessary */
-	P0.h = hi(WDOG_CTL);
-	P0.l = lo(WDOG_CTL);
-	R0 = W[P0](Z);
-	CC = BITTST(R0,1);
-	if !CC JUMP .LWRITESTAT;
-	CC = BITTST(R0,2);
-	if !CC JUMP .LWRITESTAT;
-	JUMP .LSKIP_WRITE;
-
-.LWRITESTAT:
-	/* When watch dog timer is enabled,
-	 * a write to STAT will load the contents of CNT to STAT
-	 */
-	R0 = 0x0000(z);
-	P0.h = hi(WDOG_STAT);
-	P0.l = lo(WDOG_STAT)
-	[P0] = R0;
-	SSYNC;
-
-.LSKIP_WRITE:
-	/* Enable the reset event */
-	P0.h = hi(WDOG_CTL);
-	P0.l = lo(WDOG_CTL);
-	R0 = W[P0](Z);
-	BITCLR(R0,1);
-	BITCLR(R0,2);
-	W[P0] = R0.L;
-	SSYNC;
-	NOP;
-
-	/* Enable the wdog counter */
-	R0 = W[P0](Z);
-	BITCLR(R0,4);
-	W[P0] = R0.L;
-	SSYNC;
-
-	IDLE;
-
-	RTS;
-
 .data
 
 /*

arch/blackfin/mach-bf561/head.S

@@ -406,66 +406,6 @@ ENTRY(_start_dma_code)
 ENDPROC(_start_dma_code)
 #endif /* CONFIG_BFIN_KERNEL_CLOCK */
 
-ENTRY(_bfin_reset)
-	/* No more interrupts to be handled*/
-	CLI R6;
-	SSYNC;
-
-#if defined(CONFIG_BFIN_SHARED_FLASH_ENET)
-	p0.h = hi(FIO_INEN);
-	p0.l = lo(FIO_INEN);
-	r0.l = ~(PF1 | PF0);
-	w[p0] = r0.l;
-
-	p0.h = hi(FIO_DIR);
-	p0.l = lo(FIO_DIR);
-	r0.l = (PF1 | PF0);
-	w[p0] = r0.l;
-
-	p0.h = hi(FIO_FLAG_C);
-	p0.l = lo(FIO_FLAG_C);
-	r0.l = (PF1 | PF0);
-	w[p0] = r0.l;
-#endif
-
-	/* Clear the IMASK register */
-	p0.h = hi(IMASK);
-	p0.l = lo(IMASK);
-	r0 = 0x0;
-	[p0] = r0;
-
-	/* Clear the ILAT register */
-	p0.h = hi(ILAT);
-	p0.l = lo(ILAT);
-	r0 = [p0];
-	[p0] = r0;
-	SSYNC;
-
-	/* make sure SYSCR is set to use BMODE */
-	P0.h = hi(SYSCR);
-	P0.l = lo(SYSCR);
-	R0.l = 0x20;		/* on BF561, disable core b */
-	W[P0] = R0.l;
-	SSYNC;
-
-	/* issue a system soft reset */
-	P1.h = hi(SWRST);
-	P1.l = lo(SWRST);
-	R1.l = 0x0007;
-	W[P1] = R1;
-	SSYNC;
-
-	/* clear system soft reset */
-	R0.l = 0x0000;
-	W[P0] = R0;
-	SSYNC;
-
-	/* issue core reset */
-	raise 1;
-
-	RTS;
-ENDPROC(_bfin_reset)
-
 .data
 
 /*