diff options
Diffstat (limited to 'arch/powerpc/platforms/52xx/mpc52xx_pic.c')
| -rw-r--r-- | arch/powerpc/platforms/52xx/mpc52xx_pic.c | 518 |
1 files changed, 518 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/52xx/mpc52xx_pic.c b/arch/powerpc/platforms/52xx/mpc52xx_pic.c new file mode 100644 index 000000000..76a8102bd --- /dev/null +++ b/arch/powerpc/platforms/52xx/mpc52xx_pic.c @@ -0,0 +1,518 @@ +/* + * + * 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. + * + * 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> +#include <linux/irq.h> +#include <linux/of.h> +#include <asm/io.h> +#include <asm/prom.h> +#include <asm/mpc52xx.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 const struct of_device_id mpc52xx_pic_ids[] __initconst = { + { .compatible = "fsl,mpc5200-pic", }, + { .compatible = "mpc5200-pic", }, + {} +}; +static const struct of_device_id mpc52xx_sdma_ids[] __initconst = { + { .compatible = "fsl,mpc5200-bestcomm", }, + { .compatible = "mpc5200-bestcomm", }, + {} +}; + +static struct mpc52xx_intr __iomem *intr; +static struct mpc52xx_sdma __iomem *sdma; +static struct irq_domain *mpc52xx_irqhost = NULL; + +static unsigned char mpc52xx_map_senses[4] = { + IRQ_TYPE_LEVEL_HIGH, + IRQ_TYPE_EDGE_RISING, + IRQ_TYPE_EDGE_FALLING, + 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)); +} + +static inline void io_be_clrbit(u32 __iomem *addr, int bitno) +{ + out_be32(addr, in_be32(addr) & ~(1 << bitno)); +} + +/* + * IRQ[0-3] interrupt irq_chip + */ +static void mpc52xx_extirq_mask(struct irq_data *d) +{ + int l2irq = irqd_to_hwirq(d) & MPC52xx_IRQ_L2_MASK; + io_be_clrbit(&intr->ctrl, 11 - l2irq); +} + +static void mpc52xx_extirq_unmask(struct irq_data *d) +{ + int l2irq = irqd_to_hwirq(d) & MPC52xx_IRQ_L2_MASK; + io_be_setbit(&intr->ctrl, 11 - l2irq); +} + +static void mpc52xx_extirq_ack(struct irq_data *d) +{ + int l2irq = irqd_to_hwirq(d) & MPC52xx_IRQ_L2_MASK; + io_be_setbit(&intr->ctrl, 27-l2irq); +} + +static int mpc52xx_extirq_set_type(struct irq_data *d, unsigned int flow_type) +{ + u32 ctrl_reg, type; + int l2irq = irqd_to_hwirq(d) & MPC52xx_IRQ_L2_MASK; + void *handler = handle_level_irq; + + pr_debug("%s: irq=%x. l2=%d flow_type=%d\n", __func__, + (int) irqd_to_hwirq(d), l2irq, flow_type); + + switch (flow_type) { + case IRQF_TRIGGER_HIGH: type = 0; break; + case IRQF_TRIGGER_RISING: type = 1; handler = handle_edge_irq; break; + case IRQF_TRIGGER_FALLING: type = 2; handler = handle_edge_irq; break; + case IRQF_TRIGGER_LOW: type = 3; break; + default: + type = 0; + } + + ctrl_reg = in_be32(&intr->ctrl); + ctrl_reg &= ~(0x3 << (22 - (l2irq * 2))); + ctrl_reg |= (type << (22 - (l2irq * 2))); + out_be32(&intr->ctrl, ctrl_reg); + + irq_set_handler_locked(d, handler); + + return 0; +} + +static struct irq_chip mpc52xx_extirq_irqchip = { + .name = "MPC52xx External", + .irq_mask = mpc52xx_extirq_mask, + .irq_unmask = mpc52xx_extirq_unmask, + .irq_ack = mpc52xx_extirq_ack, + .irq_set_type = mpc52xx_extirq_set_type, +}; + +/* + * Main interrupt irq_chip + */ +static int mpc52xx_null_set_type(struct irq_data *d, unsigned int flow_type) +{ + return 0; /* Do nothing so that the sense mask will get updated */ +} + +static void mpc52xx_main_mask(struct irq_data *d) +{ + int l2irq = irqd_to_hwirq(d) & MPC52xx_IRQ_L2_MASK; + io_be_setbit(&intr->main_mask, 16 - l2irq); +} + +static void mpc52xx_main_unmask(struct irq_data *d) +{ + int l2irq = irqd_to_hwirq(d) & MPC52xx_IRQ_L2_MASK; + io_be_clrbit(&intr->main_mask, 16 - l2irq); +} + +static struct irq_chip mpc52xx_main_irqchip = { + .name = "MPC52xx Main", + .irq_mask = mpc52xx_main_mask, + .irq_mask_ack = mpc52xx_main_mask, + .irq_unmask = mpc52xx_main_unmask, + .irq_set_type = mpc52xx_null_set_type, +}; + +/* + * Peripherals interrupt irq_chip + */ +static void mpc52xx_periph_mask(struct irq_data *d) +{ + int l2irq = irqd_to_hwirq(d) & MPC52xx_IRQ_L2_MASK; + io_be_setbit(&intr->per_mask, 31 - l2irq); +} + +static void mpc52xx_periph_unmask(struct irq_data *d) +{ + int l2irq = irqd_to_hwirq(d) & MPC52xx_IRQ_L2_MASK; + io_be_clrbit(&intr->per_mask, 31 - l2irq); +} + +static struct irq_chip mpc52xx_periph_irqchip = { + .name = "MPC52xx Peripherals", + .irq_mask = mpc52xx_periph_mask, + .irq_mask_ack = mpc52xx_periph_mask, + .irq_unmask = mpc52xx_periph_unmask, + .irq_set_type = mpc52xx_null_set_type, +}; + +/* + * SDMA interrupt irq_chip + */ +static void mpc52xx_sdma_mask(struct irq_data *d) +{ + int l2irq = irqd_to_hwirq(d) & MPC52xx_IRQ_L2_MASK; + io_be_setbit(&sdma->IntMask, l2irq); +} + +static void mpc52xx_sdma_unmask(struct irq_data *d) +{ + int l2irq = irqd_to_hwirq(d) & MPC52xx_IRQ_L2_MASK; + io_be_clrbit(&sdma->IntMask, l2irq); +} + +static void mpc52xx_sdma_ack(struct irq_data *d) +{ + int l2irq = irqd_to_hwirq(d) & MPC52xx_IRQ_L2_MASK; + out_be32(&sdma->IntPend, 1 << l2irq); +} + +static struct irq_chip mpc52xx_sdma_irqchip = { + .name = "MPC52xx SDMA", + .irq_mask = mpc52xx_sdma_mask, + .irq_unmask = mpc52xx_sdma_unmask, + .irq_ack = mpc52xx_sdma_ack, + .irq_set_type = mpc52xx_null_set_type, +}; + +/** + * mpc52xx_is_extirq - Returns true if hwirq number is for an external IRQ + */ +static int mpc52xx_is_extirq(int l1, int l2) +{ + return ((l1 == 0) && (l2 == 0)) || + ((l1 == 1) && (l2 >= 1) && (l2 <= 3)); +} + +/** + * mpc52xx_irqhost_xlate - translate virq# from device tree interrupts property + */ +static int mpc52xx_irqhost_xlate(struct irq_domain *h, struct device_node *ct, + const u32 *intspec, unsigned int intsize, + irq_hw_number_t *out_hwirq, + unsigned int *out_flags) +{ + int intrvect_l1; + int intrvect_l2; + int intrvect_type; + int intrvect_linux; + + if (intsize != 3) + return -1; + + intrvect_l1 = (int)intspec[0]; + intrvect_l2 = (int)intspec[1]; + intrvect_type = (int)intspec[2] & 0x3; + + intrvect_linux = (intrvect_l1 << MPC52xx_IRQ_L1_OFFSET) & + MPC52xx_IRQ_L1_MASK; + intrvect_linux |= intrvect_l2 & MPC52xx_IRQ_L2_MASK; + + *out_hwirq = intrvect_linux; + *out_flags = IRQ_TYPE_LEVEL_LOW; + if (mpc52xx_is_extirq(intrvect_l1, intrvect_l2)) + *out_flags = mpc52xx_map_senses[intrvect_type]; + + pr_debug("return %x, l1=%d, l2=%d\n", intrvect_linux, intrvect_l1, + intrvect_l2); + return 0; +} + +/** + * mpc52xx_irqhost_map - Hook to map from virq to an irq_chip structure + */ +static int mpc52xx_irqhost_map(struct irq_domain *h, unsigned int virq, + irq_hw_number_t irq) +{ + int l1irq; + int l2irq; + struct irq_chip *irqchip; + void *hndlr; + int type; + u32 reg; + + l1irq = (irq & MPC52xx_IRQ_L1_MASK) >> MPC52xx_IRQ_L1_OFFSET; + l2irq = irq & MPC52xx_IRQ_L2_MASK; + + /* + * External IRQs are handled differently by the hardware so they are + * handled by a dedicated irq_chip structure. + */ + if (mpc52xx_is_extirq(l1irq, l2irq)) { + reg = in_be32(&intr->ctrl); + type = mpc52xx_map_senses[(reg >> (22 - l2irq * 2)) & 0x3]; + if ((type == IRQ_TYPE_EDGE_FALLING) || + (type == IRQ_TYPE_EDGE_RISING)) + hndlr = handle_edge_irq; + else + hndlr = handle_level_irq; + + irq_set_chip_and_handler(virq, &mpc52xx_extirq_irqchip, hndlr); + pr_debug("%s: External IRQ%i virq=%x, hw=%x. type=%x\n", + __func__, l2irq, virq, (int)irq, type); + return 0; + } + + /* It is an internal SOC irq. Choose the correct irq_chip */ + switch (l1irq) { + case MPC52xx_IRQ_L1_MAIN: irqchip = &mpc52xx_main_irqchip; break; + case MPC52xx_IRQ_L1_PERP: irqchip = &mpc52xx_periph_irqchip; break; + case MPC52xx_IRQ_L1_SDMA: irqchip = &mpc52xx_sdma_irqchip; break; + case MPC52xx_IRQ_L1_CRIT: + pr_warn("%s: Critical IRQ #%d is unsupported! Nopping it.\n", + __func__, l2irq); + irq_set_chip(virq, &no_irq_chip); + return 0; + } + + irq_set_chip_and_handler(virq, irqchip, handle_level_irq); + pr_debug("%s: virq=%x, l1=%i, l2=%i\n", __func__, virq, l1irq, l2irq); + + return 0; +} + +static const struct irq_domain_ops mpc52xx_irqhost_ops = { + .xlate = mpc52xx_irqhost_xlate, + .map = mpc52xx_irqhost_map, +}; + +/** + * 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; + struct device_node *picnode; + struct device_node *np; + + /* Remap the necessary zones */ + picnode = of_find_matching_node(NULL, mpc52xx_pic_ids); + intr = of_iomap(picnode, 0); + if (!intr) + panic(__FILE__ ": find_and_map failed on 'mpc5200-pic'. " + "Check node !"); + + np = of_find_matching_node(NULL, mpc52xx_sdma_ids); + sdma = of_iomap(np, 0); + of_node_put(np); + if (!sdma) + panic(__FILE__ ": find_and_map failed on 'mpc5200-bestcomm'. " + "Check node !"); + + pr_debug("MPC5200 IRQ controller mapped to 0x%p\n", intr); + + /* Disable all interrupt sources. */ + out_be32(&sdma->IntPend, 0xffffffff); /* 1 means clear pending */ + out_be32(&sdma->IntMask, 0xffffffff); /* 1 means disabled */ + out_be32(&intr->per_mask, 0x7ffffc00); /* 1 means disabled */ + out_be32(&intr->main_mask, 0x00010fff); /* 1 means disabled */ + intr_ctrl = in_be32(&intr->ctrl); + intr_ctrl &= 0x00ff0000; /* Keeps IRQ[0-3] config */ + intr_ctrl |= 0x0f000000 | /* clear IRQ 0-3 */ + 0x00001000 | /* MEE master external enable */ + 0x00000000 | /* 0 means disable IRQ 0-3 */ + 0x00000001; /* CEb route critical normally */ + out_be32(&intr->ctrl, intr_ctrl); + + /* Zero a bunch of the priority settings. */ + out_be32(&intr->per_pri1, 0); + out_be32(&intr->per_pri2, 0); + out_be32(&intr->per_pri3, 0); + out_be32(&intr->main_pri1, 0); + out_be32(&intr->main_pri2, 0); + + /* + * As last step, add an irq host to translate the real + * hw irq information provided by the ofw to linux virq + */ + mpc52xx_irqhost = irq_domain_add_linear(picnode, + MPC52xx_IRQ_HIGHTESTHWIRQ, + &mpc52xx_irqhost_ops, NULL); + + if (!mpc52xx_irqhost) + panic(__FILE__ ": Cannot allocate the IRQ host\n"); + + irq_set_default_host(mpc52xx_irqhost); + + pr_info("MPC52xx PIC is up and running!\n"); +} + +/** + * mpc52xx_get_irq - Get pending interrupt number hook function + * + * Called by the interrupt 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; + int irq; + + status = in_be32(&intr->enc_status); + if (status & 0x00000400) { /* critical */ + irq = (status >> 8) & 0x3; + if (irq == 2) /* high priority peripheral */ + goto peripheral; + 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); + } 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); + } else { + irq |= (MPC52xx_IRQ_L1_PERP << MPC52xx_IRQ_L1_OFFSET); + } + } else { + return 0; + } + + return irq_linear_revmap(mpc52xx_irqhost, irq); +} |