[ARM] 4348/4: iop3xx: Give Linux control over PCI initialization

Currently the iop3xx platform support code assumes that RedBoot is the
bootloader and has already initialized the ATU.  Linux should handle this
initialization for three reasons:

1/ The memory map that RedBoot sets up is not optimal (page_to_dma and
virt_to_phys return different addresses).  The effect of this is that using
the dma mapping API for the internal bus dma units generates pci bus
addresses that are incorrect for the internal bus.

2/ Not all iop platforms use RedBoot

3/ If the ATU is already initialized it indicates that the iop is an add-in
card in another host, it does not own the PCI bus, and should not be
re-initialized.

Changelog:
* rather than change nr_controllers to zero, simply do not call
  pci_common_init

Cc: Lennert Buytenhek <kernel@wantstofly.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 139 insertions, 1 deletions

diff --git a/arch/arm/plat-iop/pci.c b/arch/arm/plat-iop/pci.c
index b5f6ec35aafb..e2744b7227c5 100644
--- a/arch/arm/plat-iop/pci.c
+++ b/arch/arm/plat-iop/pci.c
@@ -55,7 +55,7 @@ static u32 iop3xx_cfg_address(struct pci_bus *bus, int devfn, int where)
  * This routine checks the status of the last configuration cycle.  If an error
  * was detected it returns a 1, else it returns a 0.  The errors being checked
  * are parity, master abort, target abort (master and target).  These types of
- * errors occure during a config cycle where there is no device, like during
+ * errors occur during a config cycle where there is no device, like during
  * the discovery stage.
  */
 static int iop3xx_pci_status(void)
@@ -223,8 +223,111 @@ struct pci_bus *iop3xx_pci_scan_bus(int nr, struct pci_sys_data *sys)
 	return pci_scan_bus(sys->busnr, &iop3xx_ops, sys);
 }
 
+void __init iop3xx_atu_setup(void)
+{
+	/* BAR 0 ( Disabled ) */
+	*IOP3XX_IAUBAR0 = 0x0;
+	*IOP3XX_IABAR0  = 0x0;
+	*IOP3XX_IATVR0  = 0x0;
+	*IOP3XX_IALR0   = 0x0;
+
+	/* BAR 1 ( Disabled ) */
+	*IOP3XX_IAUBAR1 = 0x0;
+	*IOP3XX_IABAR1  = 0x0;
+	*IOP3XX_IALR1   = 0x0;
+
+	/* BAR 2 (1:1 mapping with Physical RAM) */
+	/* Set limit and enable */
+	*IOP3XX_IALR2 = ~((u32)IOP3XX_MAX_RAM_SIZE - 1) & ~0x1;
+	*IOP3XX_IAUBAR2 = 0x0;
+
+	/* Align the inbound bar with the base of memory */
+	*IOP3XX_IABAR2 = PHYS_OFFSET |
+			       PCI_BASE_ADDRESS_MEM_TYPE_64 |
+			       PCI_BASE_ADDRESS_MEM_PREFETCH;
+
+	*IOP3XX_IATVR2 = PHYS_OFFSET;
+
+	/* Outbound window 0 */
+	*IOP3XX_OMWTVR0 = IOP3XX_PCI_LOWER_MEM_PA;
+	*IOP3XX_OUMWTVR0 = 0;
+
+	/* Outbound window 1 */
+	*IOP3XX_OMWTVR1 = IOP3XX_PCI_LOWER_MEM_PA + IOP3XX_PCI_MEM_WINDOW_SIZE;
+	*IOP3XX_OUMWTVR1 = 0;
+
+	/* BAR 3 ( Disabled ) */
+	*IOP3XX_IAUBAR3 = 0x0;
+	*IOP3XX_IABAR3  = 0x0;
+	*IOP3XX_IATVR3  = 0x0;
+	*IOP3XX_IALR3   = 0x0;
+
+	/* Setup the I/O Bar
+	 */
+	*IOP3XX_OIOWTVR = IOP3XX_PCI_LOWER_IO_PA;;
+
+	/* Enable inbound and outbound cycles
+	 */
+	*IOP3XX_ATUCMD |= PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER |
+			       PCI_COMMAND_PARITY | PCI_COMMAND_SERR;
+	*IOP3XX_ATUCR |= IOP3XX_ATUCR_OUT_EN;
+}
+
+void __init iop3xx_atu_disable(void)
+{
+	*IOP3XX_ATUCMD = 0;
+	*IOP3XX_ATUCR = 0;
+
+	/* wait for cycles to quiesce */
+	while (*IOP3XX_PCSR & (IOP3XX_PCSR_OUT_Q_BUSY |
+				     IOP3XX_PCSR_IN_Q_BUSY))
+		cpu_relax();
+
+	/* BAR 0 ( Disabled ) */
+	*IOP3XX_IAUBAR0 = 0x0;
+	*IOP3XX_IABAR0  = 0x0;
+	*IOP3XX_IATVR0  = 0x0;
+	*IOP3XX_IALR0   = 0x0;
+
+	/* BAR 1 ( Disabled ) */
+	*IOP3XX_IAUBAR1 = 0x0;
+	*IOP3XX_IABAR1  = 0x0;
+	*IOP3XX_IALR1   = 0x0;
+
+	/* BAR 2 ( Disabled ) */
+	*IOP3XX_IAUBAR2 = 0x0;
+	*IOP3XX_IABAR2  = 0x0;
+	*IOP3XX_IATVR2  = 0x0;
+	*IOP3XX_IALR2   = 0x0;
+
+	/* BAR 3 ( Disabled ) */
+	*IOP3XX_IAUBAR3 = 0x0;
+	*IOP3XX_IABAR3  = 0x0;
+	*IOP3XX_IATVR3  = 0x0;
+	*IOP3XX_IALR3   = 0x0;
+
+	/* Clear the outbound windows */
+	*IOP3XX_OIOWTVR  = 0;
+
+	/* Outbound window 0 */
+	*IOP3XX_OMWTVR0 = 0;
+	*IOP3XX_OUMWTVR0 = 0;
+
+	/* Outbound window 1 */
+	*IOP3XX_OMWTVR1 = 0;
+	*IOP3XX_OUMWTVR1 = 0;
+}
+
+/* Flag to determine whether the ATU is initialized and the PCI bus scanned */
+int init_atu;
+
 void iop3xx_pci_preinit(void)
 {
+	if (iop3xx_get_init_atu() == IOP3XX_INIT_ATU_ENABLE) {
+		iop3xx_atu_disable();
+		iop3xx_atu_setup();
+	}
+
 	DBG("PCI:  Intel 803xx PCI init code.\n");
 	DBG("ATU: IOP3XX_ATUCMD=0x%04x\n", *IOP3XX_ATUCMD);
 	DBG("ATU: IOP3XX_OMWTVR0=0x%04x, IOP3XX_OIOWTVR=0x%04x\n",
@@ -245,3 +348,38 @@ void iop3xx_pci_preinit(void)
 
 	hook_fault_code(16+6, iop3xx_pci_abort, SIGBUS, "imprecise external abort");
 }
+
+/* allow init_atu to be user overridden */
+static int __init iop3xx_init_atu_setup(char *str)
+{
+	init_atu = IOP3XX_INIT_ATU_DEFAULT;
+	if (str) {
+		while (*str != '\0') {
+			switch (*str) {
+			case 'y':
+			case 'Y':
+				init_atu = IOP3XX_INIT_ATU_ENABLE;
+				break;
+			case 'n':
+			case 'N':
+				init_atu = IOP3XX_INIT_ATU_DISABLE;
+				break;
+			case ',':
+			case '=':
+				break;
+			default:
+				printk(KERN_DEBUG "\"%s\" malformed at "
+					    "character: \'%c\'",
+					    __FUNCTION__,
+					    *str);
+				*(str + 1) = '\0';
+			}
+			str++;
+		}
+	}
+
+	return 1;
+}
+
+__setup("iop3xx_init_atu", iop3xx_init_atu_setup);
+