MIPS: ath25: add AR2315 PCI host controller driver

Add PCI host controller driver and DMA address calculation hook.

Signed-off-by: Sergey Ryazanov <ryazanov.s.a@gmail.com>
Cc: Linux MIPS <linux-mips@linux-mips.org>
Patchwork: https://patchwork.linux-mips.org/patch/8246/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

2 files changed, 64 insertions, 0 deletions

diff --git a/arch/mips/ath25/Kconfig b/arch/mips/ath25/Kconfig
index ca3dde472bef..fc19dd57e42d 100644
--- a/arch/mips/ath25/Kconfig
+++ b/arch/mips/ath25/Kconfig
@@ -7,3 +7,10 @@ config SOC_AR2315
         bool "Atheros AR2315+ SoC support"
         depends on ATH25
         default y
+
+config PCI_AR2315
+        bool "Atheros AR2315 PCI controller support"
+        depends on SOC_AR2315
+        select HW_HAS_PCI
+        select PCI
+        default y
diff --git a/arch/mips/ath25/ar2315.c b/arch/mips/ath25/ar2315.c
index 52805b725a67..f02478915afd 100644
--- a/arch/mips/ath25/ar2315.c
+++ b/arch/mips/ath25/ar2315.c
@@ -19,6 +19,7 @@
 #include <linux/bitops.h>
 #include <linux/irqdomain.h>
 #include <linux/interrupt.h>
+#include <linux/platform_device.h>
 #include <linux/reboot.h>
 #include <asm/bootinfo.h>
 #include <asm/reboot.h>
@@ -133,6 +134,10 @@ static void ar2315_irq_dispatch(void)
 
         if (pending & CAUSEF_IP3)
                 do_IRQ(AR2315_IRQ_WLAN0);
+#ifdef CONFIG_PCI_AR2315
+        else if (pending & CAUSEF_IP5)
+                do_IRQ(AR2315_IRQ_LCBUS_PCI);
+#endif
         else if (pending & CAUSEF_IP2)
                 do_IRQ(AR2315_IRQ_MISC);
         else if (pending & CAUSEF_IP7)
@@ -296,10 +301,62 @@ void __init ar2315_plat_mem_setup(void)
         _machine_restart = ar2315_restart;
 }
 
+#ifdef CONFIG_PCI_AR2315
+static struct resource ar2315_pci_res[] = {
+        {
+                .name = "ar2315-pci-ctrl",
+                .flags = IORESOURCE_MEM,
+                .start = AR2315_PCI_BASE,
+                .end = AR2315_PCI_BASE + AR2315_PCI_SIZE - 1,
+        },
+        {
+                .name = "ar2315-pci-ext",
+                .flags = IORESOURCE_MEM,
+                .start = AR2315_PCI_EXT_BASE,
+                .end = AR2315_PCI_EXT_BASE + AR2315_PCI_EXT_SIZE - 1,
+        },
+        {
+                .name = "ar2315-pci",
+                .flags = IORESOURCE_IRQ,
+                .start = AR2315_IRQ_LCBUS_PCI,
+                .end = AR2315_IRQ_LCBUS_PCI,
+        },
+};
+#endif
+
 void __init ar2315_arch_init(void)
 {
         unsigned irq = irq_create_mapping(ar2315_misc_irq_domain,
                                           AR2315_MISC_IRQ_UART0);
 
         ath25_serial_setup(AR2315_UART0_BASE, irq, ar2315_apb_frequency());
+
+#ifdef CONFIG_PCI_AR2315
+        if (ath25_soc == ATH25_SOC_AR2315) {
+                /* Reset PCI DMA logic */
+                ar2315_rst_reg_mask(AR2315_RESET, 0, AR2315_RESET_PCIDMA);
+                msleep(20);
+                ar2315_rst_reg_mask(AR2315_RESET, AR2315_RESET_PCIDMA, 0);
+                msleep(20);
+
+                /* Configure endians */
+                ar2315_rst_reg_mask(AR2315_ENDIAN_CTL, 0, AR2315_CONFIG_PCIAHB |
+                                    AR2315_CONFIG_PCIAHB_BRIDGE);
+
+                /* Configure as PCI host with DMA */
+                ar2315_rst_reg_write(AR2315_PCICLK, AR2315_PCICLK_PLLC_CLKM |
+                                  (AR2315_PCICLK_IN_FREQ_DIV_6 <<
+                                   AR2315_PCICLK_DIV_S));
+                ar2315_rst_reg_mask(AR2315_AHB_ARB_CTL, 0, AR2315_ARB_PCI);
+                ar2315_rst_reg_mask(AR2315_IF_CTL, AR2315_IF_PCI_CLK_MASK |
+                                    AR2315_IF_MASK, AR2315_IF_PCI |
+                                    AR2315_IF_PCI_HOST | AR2315_IF_PCI_INTR |
+                                    (AR2315_IF_PCI_CLK_OUTPUT_CLK <<
+                                     AR2315_IF_PCI_CLK_SHIFT));
+
+                platform_device_register_simple("ar2315-pci", -1,
+                                                ar2315_pci_res,
+                                                ARRAY_SIZE(ar2315_pci_res));
+        }
+#endif
 }