From 639da5ee374ba8f070690bbd355ca30139ce145a Mon Sep 17 00:00:00 2001 From: Nicolas Pitre Date: Wed, 31 Aug 2011 22:55:46 -0400 Subject: ARM: add an extra temp register to the low level debugging addruart macro Some platforms (like OMAP not to name it) are doing rather complicated hacks just to determine the base UART address to use. Let's give their addruart macro some slack by providing an extra work register which will allow for much needed cleanups. This is basically a no-op as this commit is only adding the extra argument to the macro but no one is using it yet. Signed-off-by: nicolas Pitre Reviewed-by: Kevin Hilman --- arch/arm/mach-omap2/include/mach/debug-macro.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/arm/mach-omap2/include/mach/debug-macro.S') diff --git a/arch/arm/mach-omap2/include/mach/debug-macro.S b/arch/arm/mach-omap2/include/mach/debug-macro.S index 48adfe9fe4f3..fbd23ec81a20 100644 --- a/arch/arm/mach-omap2/include/mach/debug-macro.S +++ b/arch/arm/mach-omap2/include/mach/debug-macro.S @@ -34,7 +34,7 @@ omap_uart_lsr: .word 0 * the desired UART phys and virt addresses temporarily into * the omap_uart_phys and omap_uart_virt above. */ - .macro addruart, rp, rv + .macro addruart, rp, rv, tmp /* Use omap_uart_phys/virt if already configured */ 10: mrc p15, 0, \rp, c1, c0 -- cgit v1.2.3 From dd185456efce7f326c058fc12fd0df17bd8466eb Mon Sep 17 00:00:00 2001 From: Nicolas Pitre Date: Wed, 31 Aug 2011 13:57:37 -0400 Subject: ARM: plat-omap: make OMAP_UART_INFO into a relative offset This is the first step to remove PLAT_PHYS_OFFSET usage from the debug UART code. Signed-off-by: Nicolas Pitre Tested-by: Tony Lindgren Reviewed-by: Kevin Hilman --- arch/arm/mach-omap1/include/mach/debug-macro.S | 8 +++----- arch/arm/mach-omap2/include/mach/debug-macro.S | 9 ++++----- arch/arm/plat-omap/include/plat/serial.h | 6 +++--- arch/arm/plat-omap/include/plat/uncompress.h | 8 +++++++- 4 files changed, 17 insertions(+), 14 deletions(-) (limited to 'arch/arm/mach-omap2/include/mach/debug-macro.S') diff --git a/arch/arm/mach-omap1/include/mach/debug-macro.S b/arch/arm/mach-omap1/include/mach/debug-macro.S index f944ae8abc97..6a171181986f 100644 --- a/arch/arm/mach-omap1/include/mach/debug-macro.S +++ b/arch/arm/mach-omap1/include/mach/debug-macro.S @@ -46,11 +46,9 @@ omap_uart_virt: .word 0x0 bne 99f @ already configured /* Check the debug UART configuration set in uncompress.h */ - mrc p15, 0, \rp, c1, c0 - tst \rp, #1 @ MMU enabled? - ldreq \rp, =OMAP_UART_INFO @ MMU not enabled - ldrne \rp, =omap_uart_p2v(OMAP_UART_INFO) @ MMU enabled - ldr \rp, [\rp, #0] + and \rp, pc, #0xff000000 + ldr \rv, =OMAP_UART_INFO_OFS + ldr \rp, [\rp, \rv] /* Select the UART to use based on the UART1 scratchpad value */ 10: cmp \rp, #0 @ no port configured? diff --git a/arch/arm/mach-omap2/include/mach/debug-macro.S b/arch/arm/mach-omap2/include/mach/debug-macro.S index fbd23ec81a20..745e2ff3e906 100644 --- a/arch/arm/mach-omap2/include/mach/debug-macro.S +++ b/arch/arm/mach-omap2/include/mach/debug-macro.S @@ -49,11 +49,10 @@ omap_uart_lsr: .word 0 bne 99f @ already configured /* Check the debug UART configuration set in uncompress.h */ - mrc p15, 0, \rp, c1, c0 - tst \rp, #1 @ MMU enabled? - ldreq \rp, =OMAP_UART_INFO @ MMU not enabled - ldrne \rp, =omap_uart_p2v(OMAP_UART_INFO) @ MMU enabled - ldr \rp, [\rp, #0] + mov \rp, pc + ldr \rv, =OMAP_UART_INFO_OFS + and \rp, \rp, #0xff000000 + ldr \rp, [\rp, \rv] /* Select the UART to use based on the UART1 scratchpad value */ cmp \rp, #0 @ no port configured? diff --git a/arch/arm/plat-omap/include/plat/serial.h b/arch/arm/plat-omap/include/plat/serial.h index de3b10c18127..1ab9fd6abe6d 100644 --- a/arch/arm/plat-omap/include/plat/serial.h +++ b/arch/arm/plat-omap/include/plat/serial.h @@ -16,8 +16,8 @@ #include /* - * Memory entry used for the DEBUG_LL UART configuration. See also - * uncompress.h and debug-macro.S. + * Memory entry used for the DEBUG_LL UART configuration, relative to + * start of RAM. See also uncompress.h and debug-macro.S. * * Note that using a memory location for storing the UART configuration * has at least two limitations: @@ -27,7 +27,7 @@ * 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 (PLAT_PHYS_OFFSET + 0x3ffc) +#define OMAP_UART_INFO_OFS 0x3ffc /* OMAP1 serial ports */ #define OMAP1_UART1_BASE 0xfffb0000 diff --git a/arch/arm/plat-omap/include/plat/uncompress.h b/arch/arm/plat-omap/include/plat/uncompress.h index a067484cc4a2..2f472e989ec6 100644 --- a/arch/arm/plat-omap/include/plat/uncompress.h +++ b/arch/arm/plat-omap/include/plat/uncompress.h @@ -36,7 +36,13 @@ int uart_shift; */ static void set_omap_uart_info(unsigned char port) { - *(volatile u32 *)OMAP_UART_INFO = port; + /* + * Get address of some.bss variable and round it down + * a la CONFIG_AUTO_ZRELADDR. + */ + u32 ram_start = (u32)&uart_shift & 0xf8000000; + u32 *uart_info = (u32 *)(ram_start + OMAP_UART_INFO_OFS); + *uart_info = port; } static void putc(int c) -- cgit v1.2.3 From fa808a1ba5f9d40ad47c31f63691b1ded03a46f8 Mon Sep 17 00:00:00 2001 From: Nicolas Pitre Date: Thu, 1 Sep 2011 00:48:04 -0400 Subject: ARM: mach-omap2: clean up debug-macro.S This achieves two goals: 1) Get rid of omap_uart_v2p() and omap_uart_p2v() which were the last users of PLAT_PHYS_OFFSET. 2) Remove the probing of the M bit in the CP15 control reg and make the access to the .data variables completely position independent. There is a catch though: the busyuart macro needs to know where the LSR register is which might be at a different offset depending on the hardware. Given that this macro is given only two registers and that one of them must be preserved, the trick is to always pass the LSR register address around, and deduce the base address for the THR register by masking out the LSR offset in senduart instead. Signed-off-by: Nicolas Pitre Tested-by: Tony Lindgren Reviewed-by: Kevin Hilman --- arch/arm/mach-omap2/include/mach/debug-macro.S | 70 ++++++++++++-------------- 1 file changed, 31 insertions(+), 39 deletions(-) (limited to 'arch/arm/mach-omap2/include/mach/debug-macro.S') diff --git a/arch/arm/mach-omap2/include/mach/debug-macro.S b/arch/arm/mach-omap2/include/mach/debug-macro.S index 745e2ff3e906..13f98e59cfef 100644 --- a/arch/arm/mach-omap2/include/mach/debug-macro.S +++ b/arch/arm/mach-omap2/include/mach/debug-macro.S @@ -13,15 +13,10 @@ #include -#include - #include #define UART_OFFSET(addr) ((addr) & 0x00ffffff) -#define omap_uart_v2p(x) ((x) - PAGE_OFFSET + PLAT_PHYS_OFFSET) -#define omap_uart_p2v(x) ((x) - PLAT_PHYS_OFFSET + PAGE_OFFSET) - .pushsection .data omap_uart_phys: .word 0 omap_uart_virt: .word 0 @@ -37,16 +32,16 @@ omap_uart_lsr: .word 0 .macro addruart, rp, rv, tmp /* Use omap_uart_phys/virt if already configured */ -10: mrc p15, 0, \rp, c1, c0 - tst \rp, #1 @ MMU enabled? - ldreq \rp, =omap_uart_v2p(omap_uart_phys) @ MMU disabled - ldrne \rp, =omap_uart_phys @ MMU enabled - add \rv, \rp, #4 @ omap_uart_virt - ldr \rp, [\rp, #0] - ldr \rv, [\rv, #0] +10: adr \rp, 99f @ get effective addr of 99f + ldr \rv, [\rp] @ get absolute addr of 99f + sub \rv, \rv, \rp @ offset between the two + ldr \rp, [\rp, #4] @ abs addr of omap_uart_phys + sub \tmp, \rp, \rv @ make it effective + ldr \rp, [\tmp, #0] @ omap_uart_phys + ldr \rv, [\tmp, #4] @ omap_uart_virt cmp \rp, #0 @ is port configured? cmpne \rv, #0 - bne 99f @ already configured + bne 100f @ already configured /* Check the debug UART configuration set in uncompress.h */ mov \rp, pc @@ -105,50 +100,47 @@ omap_uart_lsr: .word 0 b 98f 83: mov \rp, #UART_OFFSET(TI816X_UART3_BASE) b 98f + 95: ldr \rp, =ZOOM_UART_BASE - mrc p15, 0, \rv, c1, c0 - tst \rv, #1 @ MMU enabled? - ldreq \rv, =omap_uart_v2p(omap_uart_phys) @ MMU disabled - ldrne \rv, =omap_uart_phys @ MMU enabled - str \rp, [\rv, #0] + str \rp, [\tmp, #0] @ omap_uart_phys ldr \rp, =ZOOM_UART_VIRT - add \rv, \rv, #4 @ omap_uart_virt - str \rp, [\rv, #0] + str \rp, [\tmp, #4] @ omap_uart_virt mov \rp, #(UART_LSR << ZOOM_PORT_SHIFT) - add \rv, \rv, #4 @ omap_uart_lsr - str \rp, [\rv, #0] + str \rp, [\tmp, #8] @ omap_uart_lsr b 10b /* Store both phys and virt address for the uart */ 98: add \rp, \rp, #0x48000000 @ phys base - mrc p15, 0, \rv, c1, c0 - tst \rv, #1 @ MMU enabled? - ldreq \rv, =omap_uart_v2p(omap_uart_phys) @ MMU disabled - ldrne \rv, =omap_uart_phys @ MMU enabled - str \rp, [\rv, #0] + str \rp, [\tmp, #0] @ omap_uart_phys sub \rp, \rp, #0x48000000 @ phys base add \rp, \rp, #0xfa000000 @ virt base - add \rv, \rv, #4 @ omap_uart_virt - str \rp, [\rv, #0] + str \rp, [\tmp, #4] @ omap_uart_virt mov \rp, #(UART_LSR << OMAP_PORT_SHIFT) - add \rv, \rv, #4 @ omap_uart_lsr - str \rp, [\rv, #0] + str \rp, [\tmp, #8] @ omap_uart_lsr b 10b -99: + + .align +99: .word . + .word omap_uart_phys + .ltorg + +100: /* Pass the UART_LSR reg address */ + ldr \tmp, [\tmp, #8] @ omap_uart_lsr + add \rp, \rp, \tmp + add \rv, \rv, \tmp .endm .macro senduart,rd,rx - strb \rd, [\rx] + orr \rd, \rd, \rx, lsl #24 @ preserve LSR reg offset + bic \rx, \rx, #0xff @ get base (THR) reg address + strb \rd, [\rx] @ send lower byte of rd + orr \rx, \rx, \rd, lsr #24 @ restore original rx (LSR) + bic \rd, \rd, #(0xff << 24) @ restore original rd .endm .macro busyuart,rd,rx -1001: mrc p15, 0, \rd, c1, c0 - tst \rd, #1 @ MMU enabled? - ldreq \rd, =omap_uart_v2p(omap_uart_lsr) @ MMU disabled - ldrne \rd, =omap_uart_lsr @ MMU enabled - ldr \rd, [\rd, #0] - ldrb \rd, [\rx, \rd] +1001: ldrb \rd, [\rx] @ rx contains UART_LSR address and \rd, \rd, #(UART_LSR_TEMT | UART_LSR_THRE) teq \rd, #(UART_LSR_TEMT | UART_LSR_THRE) bne 1001b -- cgit v1.2.3