238 lines
6.5 KiB
C
238 lines
6.5 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Aspeed AST24XX, AST25XX, and AST26XX SCU Interrupt Controller
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* Copyright 2019 IBM Corporation
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*
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* Eddie James <eajames@linux.ibm.com>
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*/
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#include <linux/bitops.h>
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#include <linux/irq.h>
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#include <linux/irqchip.h>
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#include <linux/irqchip/chained_irq.h>
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#include <linux/irqdomain.h>
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#include <linux/mfd/syscon.h>
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#include <linux/of_irq.h>
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#include <linux/regmap.h>
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#define ASPEED_SCU_IC_REG 0x018
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#define ASPEED_SCU_IC_SHIFT 0
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#define ASPEED_SCU_IC_ENABLE GENMASK(6, ASPEED_SCU_IC_SHIFT)
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#define ASPEED_SCU_IC_NUM_IRQS 7
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#define ASPEED_SCU_IC_STATUS_SHIFT 16
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#define ASPEED_AST2600_SCU_IC0_REG 0x560
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#define ASPEED_AST2600_SCU_IC0_SHIFT 0
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#define ASPEED_AST2600_SCU_IC0_ENABLE \
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GENMASK(5, ASPEED_AST2600_SCU_IC0_SHIFT)
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#define ASPEED_AST2600_SCU_IC0_NUM_IRQS 6
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#define ASPEED_AST2600_SCU_IC1_REG 0x570
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#define ASPEED_AST2600_SCU_IC1_SHIFT 4
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#define ASPEED_AST2600_SCU_IC1_ENABLE \
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GENMASK(5, ASPEED_AST2600_SCU_IC1_SHIFT)
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#define ASPEED_AST2600_SCU_IC1_NUM_IRQS 2
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struct aspeed_scu_ic {
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unsigned long irq_enable;
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unsigned long irq_shift;
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unsigned int num_irqs;
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unsigned int reg;
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struct regmap *scu;
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struct irq_domain *irq_domain;
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};
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static void aspeed_scu_ic_irq_handler(struct irq_desc *desc)
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{
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unsigned int sts;
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unsigned long bit;
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unsigned long enabled;
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unsigned long max;
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unsigned long status;
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struct aspeed_scu_ic *scu_ic = irq_desc_get_handler_data(desc);
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struct irq_chip *chip = irq_desc_get_chip(desc);
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unsigned int mask = scu_ic->irq_enable << ASPEED_SCU_IC_STATUS_SHIFT;
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chained_irq_enter(chip, desc);
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/*
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* The SCU IC has just one register to control its operation and read
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* status. The interrupt enable bits occupy the lower 16 bits of the
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* register, while the interrupt status bits occupy the upper 16 bits.
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* The status bit for a given interrupt is always 16 bits shifted from
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* the enable bit for the same interrupt.
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* Therefore, perform the IRQ operations in the enable bit space by
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* shifting the status down to get the mapping and then back up to
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* clear the bit.
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*/
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regmap_read(scu_ic->scu, scu_ic->reg, &sts);
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enabled = sts & scu_ic->irq_enable;
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status = (sts >> ASPEED_SCU_IC_STATUS_SHIFT) & enabled;
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bit = scu_ic->irq_shift;
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max = scu_ic->num_irqs + bit;
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for_each_set_bit_from(bit, &status, max) {
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generic_handle_domain_irq(scu_ic->irq_domain,
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bit - scu_ic->irq_shift);
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regmap_write_bits(scu_ic->scu, scu_ic->reg, mask,
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BIT(bit + ASPEED_SCU_IC_STATUS_SHIFT));
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}
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chained_irq_exit(chip, desc);
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}
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static void aspeed_scu_ic_irq_mask(struct irq_data *data)
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{
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struct aspeed_scu_ic *scu_ic = irq_data_get_irq_chip_data(data);
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unsigned int mask = BIT(data->hwirq + scu_ic->irq_shift) |
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(scu_ic->irq_enable << ASPEED_SCU_IC_STATUS_SHIFT);
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/*
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* Status bits are cleared by writing 1. In order to prevent the mask
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* operation from clearing the status bits, they should be under the
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* mask and written with 0.
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*/
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regmap_update_bits(scu_ic->scu, scu_ic->reg, mask, 0);
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}
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static void aspeed_scu_ic_irq_unmask(struct irq_data *data)
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{
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struct aspeed_scu_ic *scu_ic = irq_data_get_irq_chip_data(data);
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unsigned int bit = BIT(data->hwirq + scu_ic->irq_shift);
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unsigned int mask = bit |
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(scu_ic->irq_enable << ASPEED_SCU_IC_STATUS_SHIFT);
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/*
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* Status bits are cleared by writing 1. In order to prevent the unmask
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* operation from clearing the status bits, they should be under the
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* mask and written with 0.
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*/
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regmap_update_bits(scu_ic->scu, scu_ic->reg, mask, bit);
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}
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static int aspeed_scu_ic_irq_set_affinity(struct irq_data *data,
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const struct cpumask *dest,
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bool force)
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{
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return -EINVAL;
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}
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static struct irq_chip aspeed_scu_ic_chip = {
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.name = "aspeed-scu-ic",
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.irq_mask = aspeed_scu_ic_irq_mask,
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.irq_unmask = aspeed_scu_ic_irq_unmask,
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.irq_set_affinity = aspeed_scu_ic_irq_set_affinity,
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};
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static int aspeed_scu_ic_map(struct irq_domain *domain, unsigned int irq,
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irq_hw_number_t hwirq)
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{
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irq_set_chip_and_handler(irq, &aspeed_scu_ic_chip, handle_level_irq);
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irq_set_chip_data(irq, domain->host_data);
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return 0;
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}
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static const struct irq_domain_ops aspeed_scu_ic_domain_ops = {
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.map = aspeed_scu_ic_map,
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};
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static int aspeed_scu_ic_of_init_common(struct aspeed_scu_ic *scu_ic,
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struct device_node *node)
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{
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int irq;
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int rc = 0;
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if (!node->parent) {
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rc = -ENODEV;
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goto err;
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}
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scu_ic->scu = syscon_node_to_regmap(node->parent);
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if (IS_ERR(scu_ic->scu)) {
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rc = PTR_ERR(scu_ic->scu);
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goto err;
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}
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irq = irq_of_parse_and_map(node, 0);
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if (!irq) {
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rc = -EINVAL;
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goto err;
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}
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scu_ic->irq_domain = irq_domain_add_linear(node, scu_ic->num_irqs,
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&aspeed_scu_ic_domain_ops,
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scu_ic);
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if (!scu_ic->irq_domain) {
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rc = -ENOMEM;
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goto err;
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}
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irq_set_chained_handler_and_data(irq, aspeed_scu_ic_irq_handler,
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scu_ic);
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return 0;
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err:
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kfree(scu_ic);
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return rc;
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}
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static int __init aspeed_scu_ic_of_init(struct device_node *node,
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struct device_node *parent)
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{
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struct aspeed_scu_ic *scu_ic = kzalloc(sizeof(*scu_ic), GFP_KERNEL);
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if (!scu_ic)
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return -ENOMEM;
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scu_ic->irq_enable = ASPEED_SCU_IC_ENABLE;
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scu_ic->irq_shift = ASPEED_SCU_IC_SHIFT;
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scu_ic->num_irqs = ASPEED_SCU_IC_NUM_IRQS;
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scu_ic->reg = ASPEED_SCU_IC_REG;
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return aspeed_scu_ic_of_init_common(scu_ic, node);
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}
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static int __init aspeed_ast2600_scu_ic0_of_init(struct device_node *node,
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struct device_node *parent)
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{
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struct aspeed_scu_ic *scu_ic = kzalloc(sizeof(*scu_ic), GFP_KERNEL);
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if (!scu_ic)
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return -ENOMEM;
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scu_ic->irq_enable = ASPEED_AST2600_SCU_IC0_ENABLE;
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scu_ic->irq_shift = ASPEED_AST2600_SCU_IC0_SHIFT;
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scu_ic->num_irqs = ASPEED_AST2600_SCU_IC0_NUM_IRQS;
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scu_ic->reg = ASPEED_AST2600_SCU_IC0_REG;
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return aspeed_scu_ic_of_init_common(scu_ic, node);
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}
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static int __init aspeed_ast2600_scu_ic1_of_init(struct device_node *node,
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struct device_node *parent)
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{
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struct aspeed_scu_ic *scu_ic = kzalloc(sizeof(*scu_ic), GFP_KERNEL);
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if (!scu_ic)
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return -ENOMEM;
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scu_ic->irq_enable = ASPEED_AST2600_SCU_IC1_ENABLE;
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scu_ic->irq_shift = ASPEED_AST2600_SCU_IC1_SHIFT;
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scu_ic->num_irqs = ASPEED_AST2600_SCU_IC1_NUM_IRQS;
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scu_ic->reg = ASPEED_AST2600_SCU_IC1_REG;
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return aspeed_scu_ic_of_init_common(scu_ic, node);
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}
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IRQCHIP_DECLARE(ast2400_scu_ic, "aspeed,ast2400-scu-ic", aspeed_scu_ic_of_init);
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IRQCHIP_DECLARE(ast2500_scu_ic, "aspeed,ast2500-scu-ic", aspeed_scu_ic_of_init);
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IRQCHIP_DECLARE(ast2600_scu_ic0, "aspeed,ast2600-scu-ic0",
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aspeed_ast2600_scu_ic0_of_init);
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IRQCHIP_DECLARE(ast2600_scu_ic1, "aspeed,ast2600-scu-ic1",
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aspeed_ast2600_scu_ic1_of_init);
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