diff options
Diffstat (limited to 'arch/powerpc/platforms/512x/mpc5121_ads_cpld.c')
| -rw-r--r-- | arch/powerpc/platforms/512x/mpc5121_ads_cpld.c | 200 |
1 files changed, 200 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/512x/mpc5121_ads_cpld.c b/arch/powerpc/platforms/512x/mpc5121_ads_cpld.c new file mode 100644 index 000000000..b2981634f --- /dev/null +++ b/arch/powerpc/platforms/512x/mpc5121_ads_cpld.c @@ -0,0 +1,200 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2008 Freescale Semiconductor, Inc. All rights reserved. + * + * Author: John Rigby, <jrigby@freescale.com> + * + * Description: + * MPC5121ADS CPLD irq handling + */ + +#undef DEBUG + +#include <linux/kernel.h> +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/io.h> +#include <asm/prom.h> + +static struct device_node *cpld_pic_node; +static struct irq_domain *cpld_pic_host; + +/* + * Bits to ignore in the misc_status register + * 0x10 touch screen pendown is hard routed to irq1 + * 0x02 pci status is read from pci status register + */ +#define MISC_IGNORE 0x12 + +/* + * Nothing to ignore in pci status register + */ +#define PCI_IGNORE 0x00 + +struct cpld_pic { + u8 pci_mask; + u8 pci_status; + u8 route; + u8 misc_mask; + u8 misc_status; + u8 misc_control; +}; + +static struct cpld_pic __iomem *cpld_regs; + +static void __iomem * +irq_to_pic_mask(unsigned int irq) +{ + return irq <= 7 ? &cpld_regs->pci_mask : &cpld_regs->misc_mask; +} + +static unsigned int +irq_to_pic_bit(unsigned int irq) +{ + return 1 << (irq & 0x7); +} + +static void +cpld_mask_irq(struct irq_data *d) +{ + unsigned int cpld_irq = (unsigned int)irqd_to_hwirq(d); + void __iomem *pic_mask = irq_to_pic_mask(cpld_irq); + + out_8(pic_mask, + in_8(pic_mask) | irq_to_pic_bit(cpld_irq)); +} + +static void +cpld_unmask_irq(struct irq_data *d) +{ + unsigned int cpld_irq = (unsigned int)irqd_to_hwirq(d); + void __iomem *pic_mask = irq_to_pic_mask(cpld_irq); + + out_8(pic_mask, + in_8(pic_mask) & ~irq_to_pic_bit(cpld_irq)); +} + +static struct irq_chip cpld_pic = { + .name = "CPLD PIC", + .irq_mask = cpld_mask_irq, + .irq_ack = cpld_mask_irq, + .irq_unmask = cpld_unmask_irq, +}; + +static int +cpld_pic_get_irq(int offset, u8 ignore, u8 __iomem *statusp, + u8 __iomem *maskp) +{ + int cpld_irq; + u8 status = in_8(statusp); + u8 mask = in_8(maskp); + + /* ignore don't cares and masked irqs */ + status |= (ignore | mask); + + if (status == 0xff) + return 0; + + cpld_irq = ffz(status) + offset; + + return irq_linear_revmap(cpld_pic_host, cpld_irq); +} + +static void cpld_pic_cascade(struct irq_desc *desc) +{ + unsigned int irq; + + irq = cpld_pic_get_irq(0, PCI_IGNORE, &cpld_regs->pci_status, + &cpld_regs->pci_mask); + if (irq) { + generic_handle_irq(irq); + return; + } + + irq = cpld_pic_get_irq(8, MISC_IGNORE, &cpld_regs->misc_status, + &cpld_regs->misc_mask); + if (irq) { + generic_handle_irq(irq); + return; + } +} + +static int +cpld_pic_host_match(struct irq_domain *h, struct device_node *node, + enum irq_domain_bus_token bus_token) +{ + return cpld_pic_node == node; +} + +static int +cpld_pic_host_map(struct irq_domain *h, unsigned int virq, + irq_hw_number_t hw) +{ + irq_set_status_flags(virq, IRQ_LEVEL); + irq_set_chip_and_handler(virq, &cpld_pic, handle_level_irq); + return 0; +} + +static const struct irq_domain_ops cpld_pic_host_ops = { + .match = cpld_pic_host_match, + .map = cpld_pic_host_map, +}; + +void __init +mpc5121_ads_cpld_map(void) +{ + struct device_node *np = NULL; + + np = of_find_compatible_node(NULL, NULL, "fsl,mpc5121ads-cpld-pic"); + if (!np) { + printk(KERN_ERR "CPLD PIC init: can not find cpld-pic node\n"); + return; + } + + cpld_regs = of_iomap(np, 0); + of_node_put(np); +} + +void __init +mpc5121_ads_cpld_pic_init(void) +{ + unsigned int cascade_irq; + struct device_node *np = NULL; + + pr_debug("cpld_ic_init\n"); + + np = of_find_compatible_node(NULL, NULL, "fsl,mpc5121ads-cpld-pic"); + if (!np) { + printk(KERN_ERR "CPLD PIC init: can not find cpld-pic node\n"); + return; + } + + if (!cpld_regs) + goto end; + + cascade_irq = irq_of_parse_and_map(np, 0); + if (!cascade_irq) + goto end; + + /* + * statically route touch screen pendown through 1 + * and ignore it here + * route all others through our cascade irq + */ + out_8(&cpld_regs->route, 0xfd); + out_8(&cpld_regs->pci_mask, 0xff); + /* unmask pci ints in misc mask */ + out_8(&cpld_regs->misc_mask, ~(MISC_IGNORE)); + + cpld_pic_node = of_node_get(np); + + cpld_pic_host = irq_domain_add_linear(np, 16, &cpld_pic_host_ops, NULL); + if (!cpld_pic_host) { + printk(KERN_ERR "CPLD PIC: failed to allocate irq host!\n"); + goto end; + } + + irq_set_chained_handler(cascade_irq, cpld_pic_cascade); +end: + of_node_put(np); +} |