1// SPDX-License-Identifier: GPL-2.0+
  2/*
  3 * Driver for the external-charger IRQ pass-through function of the
  4 * Intel Bay Trail Crystal Cove PMIC.
  5 *
  6 * Note this is NOT a power_supply class driver, it just deals with IRQ
  7 * pass-through, this requires a separate driver because the PMIC's
  8 * level 2 interrupt for this must be explicitly acked.
  9 */
 10
 11#include <linux/interrupt.h>
 12#include <linux/irq.h>
 13#include <linux/irqdomain.h>
 14#include <linux/mfd/intel_soc_pmic.h>
 15#include <linux/module.h>
 16#include <linux/platform_device.h>
 17#include <linux/regmap.h>
 18
 19#define CHGRIRQ_REG					0x0a
 20#define MCHGRIRQ_REG					0x17
 21
 22struct crystal_cove_charger_data {
 23	struct mutex buslock; /* irq_bus_lock */
 24	struct irq_chip irqchip;
 25	struct regmap *regmap;
 26	struct irq_domain *irq_domain;
 27	int irq;
 28	int charger_irq;
 29	u8 mask;
 30	u8 new_mask;
 31};
 32
 33static irqreturn_t crystal_cove_charger_irq(int irq, void *data)
 34{
 35	struct crystal_cove_charger_data *charger = data;
 36
 37	/* No need to read CHGRIRQ_REG as there is only 1 IRQ */
 38	handle_nested_irq(charger->charger_irq);
 39
 40	/* Ack CHGRIRQ 0 */
 41	regmap_write(charger->regmap, CHGRIRQ_REG, BIT(0));
 42
 43	return IRQ_HANDLED;
 44}
 45
 46static void crystal_cove_charger_irq_bus_lock(struct irq_data *data)
 47{
 48	struct crystal_cove_charger_data *charger = irq_data_get_irq_chip_data(data);
 49
 50	mutex_lock(&charger->buslock);
 51}
 52
 53static void crystal_cove_charger_irq_bus_sync_unlock(struct irq_data *data)
 54{
 55	struct crystal_cove_charger_data *charger = irq_data_get_irq_chip_data(data);
 56
 57	if (charger->mask != charger->new_mask) {
 58		regmap_write(charger->regmap, MCHGRIRQ_REG, charger->new_mask);
 59		charger->mask = charger->new_mask;
 60	}
 61
 62	mutex_unlock(&charger->buslock);
 63}
 64
 65static void crystal_cove_charger_irq_unmask(struct irq_data *data)
 66{
 67	struct crystal_cove_charger_data *charger = irq_data_get_irq_chip_data(data);
 68
 69	charger->new_mask &= ~BIT(data->hwirq);
 70}
 71
 72static void crystal_cove_charger_irq_mask(struct irq_data *data)
 73{
 74	struct crystal_cove_charger_data *charger = irq_data_get_irq_chip_data(data);
 75
 76	charger->new_mask |= BIT(data->hwirq);
 77}
 78
 79static void crystal_cove_charger_rm_irq_domain(void *data)
 80{
 81	struct crystal_cove_charger_data *charger = data;
 82
 83	irq_domain_remove(charger->irq_domain);
 84}
 85
 86static int crystal_cove_charger_probe(struct platform_device *pdev)
 87{
 88	struct intel_soc_pmic *pmic = dev_get_drvdata(pdev->dev.parent);
 89	struct crystal_cove_charger_data *charger;
 90	int ret;
 91
 92	charger = devm_kzalloc(&pdev->dev, sizeof(*charger), GFP_KERNEL);
 93	if (!charger)
 94		return -ENOMEM;
 95
 96	charger->regmap = pmic->regmap;
 97	mutex_init(&charger->buslock);
 98
 99	charger->irq = platform_get_irq(pdev, 0);
100	if (charger->irq < 0)
101		return charger->irq;
102
103	charger->irq_domain = irq_domain_create_linear(dev_fwnode(pdev->dev.parent), 1,
104						       &irq_domain_simple_ops, NULL);
105	if (!charger->irq_domain)
106		return -ENOMEM;
107
108	/* Distuingish IRQ domain from others sharing (MFD) the same fwnode */
109	irq_domain_update_bus_token(charger->irq_domain, DOMAIN_BUS_WAKEUP);
110
111	ret = devm_add_action_or_reset(&pdev->dev, crystal_cove_charger_rm_irq_domain, charger);
112	if (ret)
113		return ret;
114
115	charger->charger_irq = irq_create_mapping(charger->irq_domain, 0);
116	if (!charger->charger_irq)
117		return -ENOMEM;
118
119	charger->irqchip.name = KBUILD_MODNAME;
120	charger->irqchip.irq_unmask = crystal_cove_charger_irq_unmask;
121	charger->irqchip.irq_mask = crystal_cove_charger_irq_mask;
122	charger->irqchip.irq_bus_lock = crystal_cove_charger_irq_bus_lock;
123	charger->irqchip.irq_bus_sync_unlock = crystal_cove_charger_irq_bus_sync_unlock;
124
125	irq_set_chip_data(charger->charger_irq, charger);
126	irq_set_chip_and_handler(charger->charger_irq, &charger->irqchip, handle_simple_irq);
127	irq_set_nested_thread(charger->charger_irq, true);
128	irq_set_noprobe(charger->charger_irq);
129
130	/* Mask the single 2nd level IRQ before enabling the 1st level IRQ */
131	charger->mask = charger->new_mask = BIT(0);
132	regmap_write(charger->regmap, MCHGRIRQ_REG, charger->mask);
133
134	ret = devm_request_threaded_irq(&pdev->dev, charger->irq, NULL,
135					crystal_cove_charger_irq,
136					IRQF_ONESHOT, KBUILD_MODNAME, charger);
137	if (ret)
138		return dev_err_probe(&pdev->dev, ret, "requesting irq\n");
139
140	return 0;
141}
142
143static struct platform_driver crystal_cove_charger_driver = {
144	.probe = crystal_cove_charger_probe,
145	.driver = {
146		.name = "crystal_cove_charger",
147	},
148};
149module_platform_driver(crystal_cove_charger_driver);
150
151MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com");
152MODULE_DESCRIPTION("Intel Bay Trail Crystal Cove external charger IRQ pass-through");
153MODULE_LICENSE("GPL");