247 lines
		
	
	
		
			7.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			247 lines
		
	
	
		
			7.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
// SPDX-License-Identifier: GPL-2.0
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/* (C) 2015 Pengutronix, Alexander Aring <aar@pengutronix.de>
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 *
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 * Authors:
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 * Alexander Aring <aar@pengutronix.de>
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 * Eric Anholt <eric@anholt.net>
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 */
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#include <linux/module.h>
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#include <linux/of_platform.h>
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#include <linux/platform_device.h>
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#include <linux/pm_domain.h>
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#include <dt-bindings/power/raspberrypi-power.h>
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#include <soc/bcm2835/raspberrypi-firmware.h>
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/*
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 * Firmware indices for the old power domains interface.  Only a few
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 * of them were actually implemented.
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 */
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#define RPI_OLD_POWER_DOMAIN_USB		3
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#define RPI_OLD_POWER_DOMAIN_V3D		10
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struct rpi_power_domain {
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	u32 domain;
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	bool enabled;
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	bool old_interface;
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	struct generic_pm_domain base;
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	struct rpi_firmware *fw;
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};
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struct rpi_power_domains {
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	bool has_new_interface;
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	struct genpd_onecell_data xlate;
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	struct rpi_firmware *fw;
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	struct rpi_power_domain domains[RPI_POWER_DOMAIN_COUNT];
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};
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/*
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 * Packet definition used by RPI_FIRMWARE_SET_POWER_STATE and
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 * RPI_FIRMWARE_SET_DOMAIN_STATE
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 */
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struct rpi_power_domain_packet {
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	u32 domain;
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	u32 on;
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};
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/*
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 * Asks the firmware to enable or disable power on a specific power
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 * domain.
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 */
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static int rpi_firmware_set_power(struct rpi_power_domain *rpi_domain, bool on)
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{
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	struct rpi_power_domain_packet packet;
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	packet.domain = rpi_domain->domain;
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	packet.on = on;
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	return rpi_firmware_property(rpi_domain->fw,
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				     rpi_domain->old_interface ?
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				     RPI_FIRMWARE_SET_POWER_STATE :
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				     RPI_FIRMWARE_SET_DOMAIN_STATE,
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				     &packet, sizeof(packet));
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}
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static int rpi_domain_off(struct generic_pm_domain *domain)
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{
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	struct rpi_power_domain *rpi_domain =
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		container_of(domain, struct rpi_power_domain, base);
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	return rpi_firmware_set_power(rpi_domain, false);
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}
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static int rpi_domain_on(struct generic_pm_domain *domain)
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{
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	struct rpi_power_domain *rpi_domain =
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		container_of(domain, struct rpi_power_domain, base);
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	return rpi_firmware_set_power(rpi_domain, true);
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}
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static void rpi_common_init_power_domain(struct rpi_power_domains *rpi_domains,
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					 int xlate_index, const char *name)
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{
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	struct rpi_power_domain *dom = &rpi_domains->domains[xlate_index];
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	dom->fw = rpi_domains->fw;
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	dom->base.name = name;
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	dom->base.power_on = rpi_domain_on;
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	dom->base.power_off = rpi_domain_off;
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	/*
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	 * Treat all power domains as off at boot.
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	 *
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	 * The firmware itself may be keeping some domains on, but
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	 * from Linux's perspective all we control is the refcounts
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	 * that we give to the firmware, and we can't ask the firmware
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	 * to turn off something that we haven't ourselves turned on.
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	 */
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	pm_genpd_init(&dom->base, NULL, true);
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	rpi_domains->xlate.domains[xlate_index] = &dom->base;
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}
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static void rpi_init_power_domain(struct rpi_power_domains *rpi_domains,
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				  int xlate_index, const char *name)
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{
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	struct rpi_power_domain *dom = &rpi_domains->domains[xlate_index];
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	if (!rpi_domains->has_new_interface)
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		return;
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	/* The DT binding index is the firmware's domain index minus one. */
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	dom->domain = xlate_index + 1;
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	rpi_common_init_power_domain(rpi_domains, xlate_index, name);
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}
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static void rpi_init_old_power_domain(struct rpi_power_domains *rpi_domains,
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				      int xlate_index, int domain,
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				      const char *name)
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{
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	struct rpi_power_domain *dom = &rpi_domains->domains[xlate_index];
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	dom->old_interface = true;
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	dom->domain = domain;
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	rpi_common_init_power_domain(rpi_domains, xlate_index, name);
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}
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/*
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 * Detects whether the firmware supports the new power domains interface.
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 *
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 * The firmware doesn't actually return an error on an unknown tag,
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 * and just skips over it, so we do the detection by putting an
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 * unexpected value in the return field and checking if it was
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 * unchanged.
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 */
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static bool
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rpi_has_new_domain_support(struct rpi_power_domains *rpi_domains)
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{
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	struct rpi_power_domain_packet packet;
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	int ret;
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	packet.domain = RPI_POWER_DOMAIN_ARM;
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	packet.on = ~0;
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	ret = rpi_firmware_property(rpi_domains->fw,
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				    RPI_FIRMWARE_GET_DOMAIN_STATE,
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				    &packet, sizeof(packet));
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	return ret == 0 && packet.on != ~0;
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}
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static int rpi_power_probe(struct platform_device *pdev)
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{
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	struct device_node *fw_np;
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	struct device *dev = &pdev->dev;
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	struct rpi_power_domains *rpi_domains;
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	rpi_domains = devm_kzalloc(dev, sizeof(*rpi_domains), GFP_KERNEL);
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	if (!rpi_domains)
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		return -ENOMEM;
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	rpi_domains->xlate.domains =
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		devm_kcalloc(dev,
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			     RPI_POWER_DOMAIN_COUNT,
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			     sizeof(*rpi_domains->xlate.domains),
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			     GFP_KERNEL);
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	if (!rpi_domains->xlate.domains)
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		return -ENOMEM;
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	rpi_domains->xlate.num_domains = RPI_POWER_DOMAIN_COUNT;
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	fw_np = of_parse_phandle(pdev->dev.of_node, "firmware", 0);
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	if (!fw_np) {
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		dev_err(&pdev->dev, "no firmware node\n");
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		return -ENODEV;
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	}
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	rpi_domains->fw = devm_rpi_firmware_get(&pdev->dev, fw_np);
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	of_node_put(fw_np);
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	if (!rpi_domains->fw)
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		return -EPROBE_DEFER;
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	rpi_domains->has_new_interface =
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		rpi_has_new_domain_support(rpi_domains);
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	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_I2C0, "I2C0");
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	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_I2C1, "I2C1");
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	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_I2C2, "I2C2");
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	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_VIDEO_SCALER,
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			      "VIDEO_SCALER");
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	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_VPU1, "VPU1");
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	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_HDMI, "HDMI");
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	/*
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	 * Use the old firmware interface for USB power, so that we
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	 * can turn it on even if the firmware hasn't been updated.
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	 */
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	rpi_init_old_power_domain(rpi_domains, RPI_POWER_DOMAIN_USB,
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				  RPI_OLD_POWER_DOMAIN_USB, "USB");
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	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_VEC, "VEC");
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	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_JPEG, "JPEG");
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	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_H264, "H264");
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	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_V3D, "V3D");
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	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_ISP, "ISP");
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	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_UNICAM0, "UNICAM0");
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	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_UNICAM1, "UNICAM1");
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	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CCP2RX, "CCP2RX");
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	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CSI2, "CSI2");
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	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CPI, "CPI");
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	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_DSI0, "DSI0");
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	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_DSI1, "DSI1");
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	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_TRANSPOSER,
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			      "TRANSPOSER");
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	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CCP2TX, "CCP2TX");
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	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CDP, "CDP");
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	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_ARM, "ARM");
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	of_genpd_add_provider_onecell(dev->of_node, &rpi_domains->xlate);
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	platform_set_drvdata(pdev, rpi_domains);
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	return 0;
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}
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static const struct of_device_id rpi_power_of_match[] = {
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	{ .compatible = "raspberrypi,bcm2835-power", },
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	{},
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};
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MODULE_DEVICE_TABLE(of, rpi_power_of_match);
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static struct platform_driver rpi_power_driver = {
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	.driver = {
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		.name = "raspberrypi-power",
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		.of_match_table = rpi_power_of_match,
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	},
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	.probe		= rpi_power_probe,
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};
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builtin_platform_driver(rpi_power_driver);
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MODULE_AUTHOR("Alexander Aring <aar@pengutronix.de>");
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MODULE_AUTHOR("Eric Anholt <eric@anholt.net>");
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MODULE_DESCRIPTION("Raspberry Pi power domain driver");
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MODULE_LICENSE("GPL v2");
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