drivers/irqchip/irq-digicolor.c

0001 /*
0002  * Conexant Digicolor SoCs IRQ chip driver
0003  *
0004  * Author: Baruch Siach <baruch@tkos.co.il>
0005  *
0006  * Copyright (C) 2014 Paradox Innovation Ltd.
0007  *
0008  * This file is licensed under the terms of the GNU General Public
0009  * License version 2.  This program is licensed "as is" without any
0010  * warranty of any kind, whether express or implied.
0011  */
0012
0013 #include <linux/io.h>
0014 #include <linux/irq.h>
0015 #include <linux/irqchip.h>
0016 #include <linux/of.h>
0017 #include <linux/of_address.h>
0018 #include <linux/of_irq.h>
0019 #include <linux/mfd/syscon.h>
0020 #include <linux/regmap.h>
0021
0022 #include <asm/exception.h>
0023
0024 #define UC_IRQ_CONTROL      0x04
0025
0026 #define IC_FLAG_CLEAR_LO    0x00
0027 #define IC_FLAG_CLEAR_XLO   0x04
0028 #define IC_INT0ENABLE_LO    0x10
0029 #define IC_INT0ENABLE_XLO   0x14
0030 #define IC_INT0STATUS_LO    0x18
0031 #define IC_INT0STATUS_XLO   0x1c
0032
0033 static struct irq_domain *digicolor_irq_domain;
0034
0035 static void __exception_irq_entry digicolor_handle_irq(struct pt_regs *regs)
0036 {
0037     struct irq_domain_chip_generic *dgc = digicolor_irq_domain->gc;
0038     struct irq_chip_generic *gc = dgc->gc[0];
0039     u32 status, hwirq;
0040
0041     do {
0042         status = irq_reg_readl(gc, IC_INT0STATUS_LO);
0043         if (status) {
0044             hwirq = ffs(status) - 1;
0045         } else {
0046             status = irq_reg_readl(gc, IC_INT0STATUS_XLO);
0047             if (status)
0048                 hwirq = ffs(status) - 1 + 32;
0049             else
0050                 return;
0051         }
0052
0053         generic_handle_domain_irq(digicolor_irq_domain, hwirq);
0054     } while (1);
0055 }
0056
0057 static void __init digicolor_set_gc(void __iomem *reg_base, unsigned irq_base,
0058                     unsigned en_reg, unsigned ack_reg)
0059 {
0060     struct irq_chip_generic *gc;
0061
0062     gc = irq_get_domain_generic_chip(digicolor_irq_domain, irq_base);
0063     gc->reg_base = reg_base;
0064     gc->chip_types[0].regs.ack = ack_reg;
0065     gc->chip_types[0].regs.mask = en_reg;
0066     gc->chip_types[0].chip.irq_ack = irq_gc_ack_set_bit;
0067     gc->chip_types[0].chip.irq_mask = irq_gc_mask_clr_bit;
0068     gc->chip_types[0].chip.irq_unmask = irq_gc_mask_set_bit;
0069 }
0070
0071 static int __init digicolor_of_init(struct device_node *node,
0072                 struct device_node *parent)
0073 {
0074     void __iomem *reg_base;
0075     unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
0076     struct regmap *ucregs;
0077     int ret;
0078
0079     reg_base = of_iomap(node, 0);
0080     if (!reg_base) {
0081         pr_err("%pOF: unable to map IC registers\n", node);
0082         return -ENXIO;
0083     }
0084
0085     /* disable all interrupts */
0086     writel(0, reg_base + IC_INT0ENABLE_LO);
0087     writel(0, reg_base + IC_INT0ENABLE_XLO);
0088
0089     ucregs = syscon_regmap_lookup_by_phandle(node, "syscon");
0090     if (IS_ERR(ucregs)) {
0091         pr_err("%pOF: unable to map UC registers\n", node);
0092         return PTR_ERR(ucregs);
0093     }
0094     /* channel 1, regular IRQs */
0095     regmap_write(ucregs, UC_IRQ_CONTROL, 1);
0096
0097     digicolor_irq_domain =
0098         irq_domain_add_linear(node, 64, &irq_generic_chip_ops, NULL);
0099     if (!digicolor_irq_domain) {
0100         pr_err("%pOF: unable to create IRQ domain\n", node);
0101         return -ENOMEM;
0102     }
0103
0104     ret = irq_alloc_domain_generic_chips(digicolor_irq_domain, 32, 1,
0105                          "digicolor_irq", handle_level_irq,
0106                          clr, 0, 0);
0107     if (ret) {
0108         pr_err("%pOF: unable to allocate IRQ gc\n", node);
0109         return ret;
0110     }
0111
0112     digicolor_set_gc(reg_base, 0, IC_INT0ENABLE_LO, IC_FLAG_CLEAR_LO);
0113     digicolor_set_gc(reg_base, 32, IC_INT0ENABLE_XLO, IC_FLAG_CLEAR_XLO);
0114
0115     set_handle_irq(digicolor_handle_irq);
0116
0117     return 0;
0118 }
0119 IRQCHIP_DECLARE(conexant_digicolor_ic, "cnxt,cx92755-ic", digicolor_of_init);