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Commit 96554d70 authored by Tony Lindgren's avatar Tony Lindgren
Browse files

omap: Use a memory address for storing the debug port info instead of UART1 scratchpad 



This removes the dependency to the UART1 being available for storing
the debug configuration in uncompress.h. This will simplify the
DEBUG_LL UART configuration for boards that may not have UART1, or
have an external UART as it requires only one mapping for DEBUG_LL.

The patch has a few limitations. Basically now we're assuming that
the kernel uncompress code won't overlap with OMAP_UART_INFO. We also
assume the printascii is called at least once before paging_init in
order for addruart to have a chance to read the UART setup from
OMAP_UART_INFO.

As suggested by Cyril Chemparathy <cyril@ti.com>,
Vikram Pandita <vikram.pandita@ti.com> and
Kevin Hilman <khilman@deeprootsystems.com>. Based on an earlier
patch posted for Davinci by Cyril Chemparathy <cyril@ti.com>.

Signed-off-by: default avatarTony Lindgren <tony@atomide.com>
parent daa49495

arch/arm/mach-omap1/include/mach/debug-macro.S

+6 −15
Original line number Diff line number Diff line
@@ -13,6 +13,8 @@ 


#include <linux/serial_reg.h>



#include <asm/memory.h>



#include <plat/serial.h>



		.pushsection .data
@@ -37,23 +39,12 @@ omap_uart_virt: .word 0x0 
		cmp	\rx, #0			@ is port configured?

		bne	99f			@ already configured



		/* Check 7XX UART1 scratchpad register for uart to use */

		/* Check the debug UART configuration set in uncompress.h */

		mrc	p15, 0, \rx, c1, c0

		tst	\rx, #1			@ MMU enabled?

		moveq	\rx, #0xff000000	@ physical base address

		movne	\rx, #0xfe000000	@ virtual base

		orr	\rx, \rx, #0x00fb0000	@ OMAP1UART1

		ldrb	\rx, [\rx, #(UART_SCR << OMAP7XX_PORT_SHIFT)]

		cmp	\rx, #0			@ anything in 7XX scratchpad?

		bne	10f			@ found 7XX uart



		/* Check 15xx/16xx UART1 scratchpad register for uart to use */

		mrc	p15, 0, \rx, c1, c0

		tst	\rx, #1			@ MMU enabled?

		moveq	\rx, #0xff000000	@ physical base address

		movne	\rx, #0xfe000000	@ virtual base

		orr	\rx, \rx, #0x00fb0000	@ OMAP1UART1

		ldrb	\rx, [\rx, #(UART_SCR << OMAP_PORT_SHIFT)]

		ldreq	\rx, =OMAP_UART_INFO

		ldrne	\rx, =__phys_to_virt(OMAP_UART_INFO)

		ldr	\rx, [\rx, #0]



		/* Select the UART to use based on the UART1 scratchpad value */

10:		cmp	\rx, #0			@ no port configured?

arch/arm/mach-omap2/include/mach/debug-macro.S

+6 −5
Original line number Diff line number Diff line
@@ -13,6 +13,8 @@ 


#include <linux/serial_reg.h>



#include <asm/memory.h>



#include <plat/serial.h>



#define UART_OFFSET(addr)	((addr) & 0x00ffffff)
@@ -40,13 +42,12 @@ omap_uart_lsr: .word 0 
		cmp	\rx, #0			@ is port configured?

		bne	99f			@ already configured



		/* Check UART1 scratchpad register for uart to use */

		/* Check the debug UART configuration set in uncompress.h */

		mrc	p15, 0, \rx, c1, c0

		tst	\rx, #1			@ MMU enabled?

		moveq	\rx, #0x48000000	@ physical base address

		movne	\rx, #0xfa000000	@ virtual base

		orr	\rx, \rx, #0x0006a000	@ uart1 on omap2/3/4

		ldrb	\rx, [\rx, #(UART_SCR << OMAP_PORT_SHIFT)] @ scratchpad

		ldreq	\rx, =OMAP_UART_INFO

		ldrne	\rx, =__phys_to_virt(OMAP_UART_INFO)

		ldr	\rx, [\rx, #0]



		/* Select the UART to use based on the UART1 scratchpad value */

		cmp	\rx, #0			@ no port configured?

arch/arm/plat-omap/include/plat/serial.h

+14 −0
Original line number Diff line number Diff line
@@ -15,6 +15,20 @@ 


#include <linux/init.h>



/*

 * Memory entry used for the DEBUG_LL UART configuration. See also

 * uncompress.h and debug-macro.S.

 *

 * Note that using a memory location for storing the UART configuration

 * has at least two limitations:

 *

 * 1. Kernel uncompress code cannot overlap OMAP_UART_INFO as the

 *    uncompress code could then partially overwrite itself

 * 2. We assume printascii is called at least once before paging_init,

 *    and addruart has a chance to read OMAP_UART_INFO

 */

#define OMAP_UART_INFO		(PHYS_OFFSET + 0x3ffc)



/* OMAP1 serial ports */

#define OMAP1_UART1_BASE	0xfffb0000

#define OMAP1_UART2_BASE	0xfffb0800

arch/arm/plat-omap/include/plat/uncompress.h

+17 −27
Original line number Diff line number Diff line
@@ -20,27 +20,21 @@ 
#include <linux/types.h>

#include <linux/serial_reg.h>



#include <asm/memory.h>

#include <asm/mach-types.h>



#include <plat/serial.h>



static volatile u8 *uart1_base;

static int uart1_shift;



static volatile u8 *uart_base;

static int uart_shift;



/*

 * Store the DEBUG_LL uart number into UART1 scratchpad register.

 * Store the DEBUG_LL uart number into memory.

 * See also debug-macro.S, and serial.c for related code.

 *

 * Please note that we currently assume that:

 * - UART1 clocks are enabled for register access

 * - UART1 scratchpad register can be used

 */

static void set_uart1_scratchpad(unsigned char port)

static void set_omap_uart_info(unsigned char port)

{

	uart1_base[UART_SCR << uart1_shift] = port;

	*(volatile u32 *)OMAP_UART_INFO = port;

}



static void putc(int c)
@@ -60,42 +54,38 @@ static inline void flush(void) 
/*

 * Macros to configure UART1 and debug UART

 */

#define _DEBUG_LL_ENTRY(mach, uart1_phys, uart1_shft,			\

			dbg_uart, dbg_shft, dbg_id)			\

#define _DEBUG_LL_ENTRY(mach, dbg_uart, dbg_shft, dbg_id)		\

	if (machine_is_##mach()) {					\

		uart1_base = (volatile u8 *)(uart1_phys);		\

		uart1_shift = (uart1_shft);				\

		uart_base = (volatile u8 *)(dbg_uart);			\

		uart_shift = (dbg_shft);				\

		port = (dbg_id);					\

		set_uart1_scratchpad(port);				\

		set_omap_uart_info(port);				\

		break;							\

	}



#define DEBUG_LL_OMAP7XX(p, mach)					\

	_DEBUG_LL_ENTRY(mach, OMAP1_UART1_BASE, OMAP7XX_PORT_SHIFT,	\

		OMAP1_UART##p##_BASE, OMAP7XX_PORT_SHIFT, OMAP1UART##p)

	_DEBUG_LL_ENTRY(mach, OMAP1_UART##p##_BASE, OMAP7XX_PORT_SHIFT,	\

		OMAP1UART##p)



#define DEBUG_LL_OMAP1(p, mach)						\

	_DEBUG_LL_ENTRY(mach, OMAP1_UART1_BASE, OMAP_PORT_SHIFT,	\

		OMAP1_UART##p##_BASE, OMAP_PORT_SHIFT, OMAP1UART##p)

	_DEBUG_LL_ENTRY(mach, OMAP1_UART##p##_BASE, OMAP_PORT_SHIFT,	\

		OMAP1UART##p)



#define DEBUG_LL_OMAP2(p, mach)						\

	_DEBUG_LL_ENTRY(mach, OMAP2_UART1_BASE, OMAP_PORT_SHIFT,	\

		OMAP2_UART##p##_BASE, OMAP_PORT_SHIFT, OMAP2UART##p)

	_DEBUG_LL_ENTRY(mach, OMAP2_UART##p##_BASE, OMAP_PORT_SHIFT,	\

		OMAP2UART##p)



#define DEBUG_LL_OMAP3(p, mach)						\

	_DEBUG_LL_ENTRY(mach, OMAP3_UART1_BASE, OMAP_PORT_SHIFT,	\

		OMAP3_UART##p##_BASE, OMAP_PORT_SHIFT, OMAP3UART##p)

	_DEBUG_LL_ENTRY(mach, OMAP3_UART##p##_BASE, OMAP_PORT_SHIFT,	\

		OMAP3UART##p)



#define DEBUG_LL_OMAP4(p, mach)						\

	_DEBUG_LL_ENTRY(mach, OMAP4_UART1_BASE, OMAP_PORT_SHIFT,	\

		OMAP4_UART##p##_BASE, OMAP_PORT_SHIFT, OMAP4UART##p)

	_DEBUG_LL_ENTRY(mach, OMAP4_UART##p##_BASE, OMAP_PORT_SHIFT,	\

		OMAP4UART##p)



/* Zoom2/3 shift is different for UART1 and external port */

#define DEBUG_LL_ZOOM(mach)						\

	_DEBUG_LL_ENTRY(mach, OMAP2_UART1_BASE, OMAP_PORT_SHIFT,	\

		ZOOM_UART_BASE, ZOOM_PORT_SHIFT, ZOOM_UART)

	_DEBUG_LL_ENTRY(mach, ZOOM_UART_BASE, ZOOM_PORT_SHIFT, ZOOM_UART)



static inline void __arch_decomp_setup(unsigned long arch_id)

{