diff options
Diffstat (limited to 'arch/powerpc/platforms/52xx/mpc52xx_pic.c')
| -rw-r--r-- | arch/powerpc/platforms/52xx/mpc52xx_pic.c | 237 |
1 files changed, 172 insertions, 65 deletions
diff --git a/arch/powerpc/platforms/52xx/mpc52xx_pic.c b/arch/powerpc/platforms/52xx/mpc52xx_pic.c index 8479394..72865e8 100644 --- a/arch/powerpc/platforms/52xx/mpc52xx_pic.c +++ b/arch/powerpc/platforms/52xx/mpc52xx_pic.c @@ -2,20 +2,100 @@ * * Programmable Interrupt Controller functions for the Freescale MPC52xx. * + * Copyright (C) 2008 Secret Lab Technologies Ltd. * Copyright (C) 2006 bplan GmbH + * Copyright (C) 2004 Sylvain Munaut <tnt@246tNt.com> + * Copyright (C) 2003 Montavista Software, Inc * * Based on the code from the 2.4 kernel by * Dale Farnsworth <dfarnsworth@mvista.com> and Kent Borg. * - * Copyright (C) 2004 Sylvain Munaut <tnt@246tNt.com> - * Copyright (C) 2003 Montavista Software, Inc - * * This file is licensed under the terms of the GNU General Public License * version 2. This program is licensed "as is" without any warranty of any * kind, whether express or implied. * */ +/* + * This is the device driver for the MPC5200 interrupt controller. + * + * hardware overview + * ----------------- + * The MPC5200 interrupt controller groups the all interrupt sources into + * three groups called 'critical', 'main', and 'peripheral'. The critical + * group has 3 irqs, External IRQ0, slice timer 0 irq, and wake from deep + * sleep. Main group include the other 3 external IRQs, slice timer 1, RTC, + * gpios, and the general purpose timers. Peripheral group contains the + * remaining irq sources from all of the on-chip peripherals (PSCs, Ethernet, + * USB, DMA, etc). + * + * virqs + * ----- + * The Linux IRQ subsystem requires that each irq source be assigned a + * system wide unique IRQ number starting at 1 (0 means no irq). Since + * systems can have multiple interrupt controllers, the virtual IRQ (virq) + * infrastructure lets each interrupt controller to define a local set + * of IRQ numbers and the virq infrastructure maps those numbers into + * a unique range of the global IRQ# space. + * + * To define a range of virq numbers for this controller, this driver first + * assigns a number to each of the irq groups (called the level 1 or L1 + * value). Within each group individual irq sources are also assigned a + * number, as defined by the MPC5200 user guide, and refers to it as the + * level 2 or L2 value. The virq number is determined by shifting up the + * L1 value by MPC52xx_IRQ_L1_OFFSET and ORing it with the L2 value. + * + * For example, the TMR0 interrupt is irq 9 in the main group. The + * virq for TMR0 is calculated by ((1 << MPC52xx_IRQ_L1_OFFSET) | 9). + * + * The observant reader will also notice that this driver defines a 4th + * interrupt group called 'bestcomm'. The bestcomm group isn't physically + * part of the MPC5200 interrupt controller, but it is used here to assign + * a separate virq number for each bestcomm task (since any of the 16 + * bestcomm tasks can cause the bestcomm interrupt to be raised). When a + * bestcomm interrupt occurs (peripheral group, irq 0) this driver determines + * which task needs servicing and returns the irq number for that task. This + * allows drivers which use bestcomm to define their own interrupt handlers. + * + * irq_chip structures + * ------------------- + * For actually manipulating IRQs (masking, enabling, clearing, etc) this + * driver defines four separate 'irq_chip' structures, one for the main + * group, one for the peripherals group, one for the bestcomm group and one + * for external interrupts. The irq_chip structures provide the hooks needed + * to manipulate each IRQ source, and since each group is has a separate set + * of registers for controlling the irq, it makes sense to divide up the + * hooks along those lines. + * + * You'll notice that there is not an irq_chip for the critical group and + * you'll also notice that there is an irq_chip defined for external + * interrupts even though there is no external interrupt group. The reason + * for this is that the four external interrupts are all managed with the same + * register even though one of the external IRQs is in the critical group and + * the other three are in the main group. For this reason it makes sense for + * the 4 external irqs to be managed using a separate set of hooks. The + * reason there is no crit irq_chip is that of the 3 irqs in the critical + * group, only external interrupt is actually support at this time by this + * driver and since external interrupt is the only one used, it can just + * be directed to make use of the external irq irq_chip. + * + * device tree bindings + * -------------------- + * The device tree bindings for this controller reflect the two level + * organization of irqs in the device. #interrupt-cells = <3> where the + * first cell is the group number [0..3], the second cell is the irq + * number in the group, and the third cell is the sense type (level/edge). + * For reference, the following is a list of the interrupt property values + * associated with external interrupt sources on the MPC5200 (just because + * it is non-obvious to determine what the interrupts property should be + * when reading the mpc5200 manual and it is a frequently asked question). + * + * External interrupts: + * <0 0 n> external irq0, n is sense (n=0: level high, + * <1 1 n> external irq1, n is sense n=1: edge rising, + * <1 2 n> external irq2, n is sense n=2: edge falling, + * <1 3 n> external irq3, n is sense n=3: level low) + */ #undef DEBUG #include <linux/interrupt.h> @@ -24,11 +104,19 @@ #include <asm/io.h> #include <asm/prom.h> #include <asm/mpc52xx.h> -#include "mpc52xx_pic.h" -/* - * -*/ +/* HW IRQ mapping */ +#define MPC52xx_IRQ_L1_CRIT (0) +#define MPC52xx_IRQ_L1_MAIN (1) +#define MPC52xx_IRQ_L1_PERP (2) +#define MPC52xx_IRQ_L1_SDMA (3) + +#define MPC52xx_IRQ_L1_OFFSET (6) +#define MPC52xx_IRQ_L1_MASK (0x00c0) +#define MPC52xx_IRQ_L2_MASK (0x003f) + +#define MPC52xx_IRQ_HIGHTESTHWIRQ (0xd0) + /* MPC5200 device tree match tables */ static struct of_device_id mpc52xx_pic_ids[] __initdata = { @@ -53,10 +141,7 @@ static unsigned char mpc52xx_map_senses[4] = { IRQ_TYPE_LEVEL_LOW, }; -/* - * -*/ - +/* Utility functions */ static inline void io_be_setbit(u32 __iomem *addr, int bitno) { out_be32(addr, in_be32(addr) | (1 << bitno)); @@ -69,15 +154,14 @@ static inline void io_be_clrbit(u32 __iomem *addr, int bitno) /* * IRQ[0-3] interrupt irq_chip -*/ - + */ static void mpc52xx_extirq_mask(unsigned int virq) { int irq; int l2irq; irq = irq_map[virq].hwirq; - l2irq = (irq & MPC52xx_IRQ_L2_MASK) >> MPC52xx_IRQ_L2_OFFSET; + l2irq = irq & MPC52xx_IRQ_L2_MASK; pr_debug("%s: irq=%x. l2=%d\n", __func__, irq, l2irq); @@ -90,7 +174,7 @@ static void mpc52xx_extirq_unmask(unsigned int virq) int l2irq; irq = irq_map[virq].hwirq; - l2irq = (irq & MPC52xx_IRQ_L2_MASK) >> MPC52xx_IRQ_L2_OFFSET; + l2irq = irq & MPC52xx_IRQ_L2_MASK; pr_debug("%s: irq=%x. l2=%d\n", __func__, irq, l2irq); @@ -103,7 +187,7 @@ static void mpc52xx_extirq_ack(unsigned int virq) int l2irq; irq = irq_map[virq].hwirq; - l2irq = (irq & MPC52xx_IRQ_L2_MASK) >> MPC52xx_IRQ_L2_OFFSET; + l2irq = irq & MPC52xx_IRQ_L2_MASK; pr_debug("%s: irq=%x. l2=%d\n", __func__, irq, l2irq); @@ -117,7 +201,7 @@ static int mpc52xx_extirq_set_type(unsigned int virq, unsigned int flow_type) int l2irq; irq = irq_map[virq].hwirq; - l2irq = (irq & MPC52xx_IRQ_L2_MASK) >> MPC52xx_IRQ_L2_OFFSET; + l2irq = irq & MPC52xx_IRQ_L2_MASK; pr_debug("%s: irq=%x. l2=%d flow_type=%d\n", __func__, irq, l2irq, flow_type); @@ -156,15 +240,14 @@ static struct irq_chip mpc52xx_extirq_irqchip = { /* * Main interrupt irq_chip -*/ - + */ static void mpc52xx_main_mask(unsigned int virq) { int irq; int l2irq; irq = irq_map[virq].hwirq; - l2irq = (irq & MPC52xx_IRQ_L2_MASK) >> MPC52xx_IRQ_L2_OFFSET; + l2irq = irq & MPC52xx_IRQ_L2_MASK; pr_debug("%s: irq=%x. l2=%d\n", __func__, irq, l2irq); @@ -177,7 +260,7 @@ static void mpc52xx_main_unmask(unsigned int virq) int l2irq; irq = irq_map[virq].hwirq; - l2irq = (irq & MPC52xx_IRQ_L2_MASK) >> MPC52xx_IRQ_L2_OFFSET; + l2irq = irq & MPC52xx_IRQ_L2_MASK; pr_debug("%s: irq=%x. l2=%d\n", __func__, irq, l2irq); @@ -193,15 +276,14 @@ static struct irq_chip mpc52xx_main_irqchip = { /* * Peripherals interrupt irq_chip -*/ - + */ static void mpc52xx_periph_mask(unsigned int virq) { int irq; int l2irq; irq = irq_map[virq].hwirq; - l2irq = (irq & MPC52xx_IRQ_L2_MASK) >> MPC52xx_IRQ_L2_OFFSET; + l2irq = irq & MPC52xx_IRQ_L2_MASK; pr_debug("%s: irq=%x. l2=%d\n", __func__, irq, l2irq); @@ -214,7 +296,7 @@ static void mpc52xx_periph_unmask(unsigned int virq) int l2irq; irq = irq_map[virq].hwirq; - l2irq = (irq & MPC52xx_IRQ_L2_MASK) >> MPC52xx_IRQ_L2_OFFSET; + l2irq = irq & MPC52xx_IRQ_L2_MASK; pr_debug("%s: irq=%x. l2=%d\n", __func__, irq, l2irq); @@ -230,15 +312,14 @@ static struct irq_chip mpc52xx_periph_irqchip = { /* * SDMA interrupt irq_chip -*/ - + */ static void mpc52xx_sdma_mask(unsigned int virq) { int irq; int l2irq; irq = irq_map[virq].hwirq; - l2irq = (irq & MPC52xx_IRQ_L2_MASK) >> MPC52xx_IRQ_L2_OFFSET; + l2irq = irq & MPC52xx_IRQ_L2_MASK; pr_debug("%s: irq=%x. l2=%d\n", __func__, irq, l2irq); @@ -251,7 +332,7 @@ static void mpc52xx_sdma_unmask(unsigned int virq) int l2irq; irq = irq_map[virq].hwirq; - l2irq = (irq & MPC52xx_IRQ_L2_MASK) >> MPC52xx_IRQ_L2_OFFSET; + l2irq = irq & MPC52xx_IRQ_L2_MASK; pr_debug("%s: irq=%x. l2=%d\n", __func__, irq, l2irq); @@ -264,7 +345,7 @@ static void mpc52xx_sdma_ack(unsigned int virq) int l2irq; irq = irq_map[virq].hwirq; - l2irq = (irq & MPC52xx_IRQ_L2_MASK) >> MPC52xx_IRQ_L2_OFFSET; + l2irq = irq & MPC52xx_IRQ_L2_MASK; pr_debug("%s: irq=%x. l2=%d\n", __func__, irq, l2irq); @@ -278,13 +359,12 @@ static struct irq_chip mpc52xx_sdma_irqchip = { .ack = mpc52xx_sdma_ack, }; -/* - * irq_host -*/ - +/** + * mpc52xx_irqhost_xlate - translate virq# from device tree interrupts property + */ static int mpc52xx_irqhost_xlate(struct irq_host *h, struct device_node *ct, - u32 * intspec, unsigned int intsize, - irq_hw_number_t * out_hwirq, + u32 *intspec, unsigned int intsize, + irq_hw_number_t *out_hwirq, unsigned int *out_flags) { int intrvect_l1; @@ -299,10 +379,9 @@ static int mpc52xx_irqhost_xlate(struct irq_host *h, struct device_node *ct, intrvect_l2 = (int)intspec[1]; intrvect_type = (int)intspec[2]; - intrvect_linux = - (intrvect_l1 << MPC52xx_IRQ_L1_OFFSET) & MPC52xx_IRQ_L1_MASK; - intrvect_linux |= - (intrvect_l2 << MPC52xx_IRQ_L2_OFFSET) & MPC52xx_IRQ_L2_MASK; + intrvect_linux = (intrvect_l1 << MPC52xx_IRQ_L1_OFFSET) & + MPC52xx_IRQ_L1_MASK; + intrvect_linux |= intrvect_l2 & MPC52xx_IRQ_L2_MASK; pr_debug("return %x, l1=%d, l2=%d\n", intrvect_linux, intrvect_l1, intrvect_l2); @@ -313,11 +392,11 @@ static int mpc52xx_irqhost_xlate(struct irq_host *h, struct device_node *ct, return 0; } -/* - * this function retrieves the correct IRQ type out - * of the MPC regs - * Only externals IRQs needs this -*/ +/** + * mpc52xx_irqx_gettype - determine the IRQ sense type (level/edge) + * + * Only external IRQs need this. + */ static int mpc52xx_irqx_gettype(int irq) { int type; @@ -329,6 +408,9 @@ static int mpc52xx_irqx_gettype(int irq) return mpc52xx_map_senses[type]; } +/** + * mpc52xx_irqhost_map - Hook to map from virq to an irq_chip structure + */ static int mpc52xx_irqhost_map(struct irq_host *h, unsigned int virq, irq_hw_number_t irq) { @@ -339,7 +421,7 @@ static int mpc52xx_irqhost_map(struct irq_host *h, unsigned int virq, int type; l1irq = (irq & MPC52xx_IRQ_L1_MASK) >> MPC52xx_IRQ_L1_OFFSET; - l2irq = (irq & MPC52xx_IRQ_L2_MASK) >> MPC52xx_IRQ_L2_OFFSET; + l2irq = irq & MPC52xx_IRQ_L2_MASK; /* * Most of ours IRQs will be level low @@ -379,8 +461,7 @@ static int mpc52xx_irqhost_map(struct irq_host *h, unsigned int virq, break; default: - pr_debug("%s: Error, unknown L1 IRQ (0x%x)\n", __func__, l1irq); - printk(KERN_ERR "Unknow IRQ!\n"); + pr_err("%s: invalid virq requested (0x%x)\n", __func__, virq); return -EINVAL; } @@ -406,10 +487,15 @@ static struct irq_host_ops mpc52xx_irqhost_ops = { .map = mpc52xx_irqhost_map, }; -/* - * init (public) -*/ - +/** + * mpc52xx_init_irq - Initialize and register with the virq subsystem + * + * Hook for setting up IRQs on an mpc5200 system. A pointer to this function + * is to be put into the machine definition structure. + * + * This function searches the device tree for an MPC5200 interrupt controller, + * initializes it, and registers it with the virq subsystem. + */ void __init mpc52xx_init_irq(void) { u32 intr_ctrl; @@ -454,7 +540,6 @@ void __init mpc52xx_init_irq(void) * As last step, add an irq host to translate the real * hw irq information provided by the ofw to linux virq */ - mpc52xx_irqhost = irq_alloc_host(picnode, IRQ_HOST_MAP_LINEAR, MPC52xx_IRQ_HIGHTESTHWIRQ, &mpc52xx_irqhost_ops, -1); @@ -462,12 +547,38 @@ void __init mpc52xx_init_irq(void) if (!mpc52xx_irqhost) panic(__FILE__ ": Cannot allocate the IRQ host\n"); - printk(KERN_INFO "MPC52xx PIC is up and running!\n"); + irq_set_default_host(mpc52xx_irqhost); + + pr_info("MPC52xx PIC is up and running!\n"); } -/* - * get_irq (public) -*/ +/** + * mpc52xx_get_irq - Get pending interrupt number hook function + * + * Called by the interupt handler to determine what IRQ handler needs to be + * executed. + * + * Status of pending interrupts is determined by reading the encoded status + * register. The encoded status register has three fields; one for each of the + * types of interrupts defined by the controller - 'critical', 'main' and + * 'peripheral'. This function reads the status register and returns the IRQ + * number associated with the highest priority pending interrupt. 'Critical' + * interrupts have the highest priority, followed by 'main' interrupts, and + * then 'peripheral'. + * + * The mpc5200 interrupt controller can be configured to boost the priority + * of individual 'peripheral' interrupts. If this is the case then a special + * value will appear in either the crit or main fields indicating a high + * or medium priority peripheral irq has occurred. + * + * This function checks each of the 3 irq request fields and returns the + * first pending interrupt that it finds. + * + * This function also identifies a 4th type of interrupt; 'bestcomm'. Each + * bestcomm DMA task can raise the bestcomm peripheral interrupt. When this + * occurs at task-specific IRQ# is decoded so that each task can have its + * own IRQ handler. + */ unsigned int mpc52xx_get_irq(void) { u32 status; @@ -478,25 +589,21 @@ unsigned int mpc52xx_get_irq(void) irq = (status >> 8) & 0x3; if (irq == 2) /* high priority peripheral */ goto peripheral; - irq |= (MPC52xx_IRQ_L1_CRIT << MPC52xx_IRQ_L1_OFFSET) & - MPC52xx_IRQ_L1_MASK; + irq |= (MPC52xx_IRQ_L1_CRIT << MPC52xx_IRQ_L1_OFFSET); } else if (status & 0x00200000) { /* main */ irq = (status >> 16) & 0x1f; if (irq == 4) /* low priority peripheral */ goto peripheral; - irq |= (MPC52xx_IRQ_L1_MAIN << MPC52xx_IRQ_L1_OFFSET) & - MPC52xx_IRQ_L1_MASK; + irq |= (MPC52xx_IRQ_L1_MAIN << MPC52xx_IRQ_L1_OFFSET); } else if (status & 0x20000000) { /* peripheral */ peripheral: irq = (status >> 24) & 0x1f; if (irq == 0) { /* bestcomm */ status = in_be32(&sdma->IntPend); irq = ffs(status) - 1; - irq |= (MPC52xx_IRQ_L1_SDMA << MPC52xx_IRQ_L1_OFFSET) & - MPC52xx_IRQ_L1_MASK; + irq |= (MPC52xx_IRQ_L1_SDMA << MPC52xx_IRQ_L1_OFFSET); } else { - irq |= (MPC52xx_IRQ_L1_PERP << MPC52xx_IRQ_L1_OFFSET) & - MPC52xx_IRQ_L1_MASK; + irq |= (MPC52xx_IRQ_L1_PERP << MPC52xx_IRQ_L1_OFFSET); } } |