1 files changed, 247 insertions, 0 deletions

diff --git a/drivers/soc/bcm/raspberrypi-power.c b/drivers/soc/bcm/raspberrypi-power.c
new file mode 100644
index 000000000000..fe96a8b956fb
--- /dev/null
+++ b/drivers/soc/bcm/raspberrypi-power.c
@@ -0,0 +1,247 @@
+/* (C) 2015 Pengutronix, Alexander Aring <aar@pengutronix.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Authors:
+ * Alexander Aring <aar@pengutronix.de>
+ * Eric Anholt <eric@anholt.net>
+ */
+
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/pm_domain.h>
+#include <dt-bindings/power/raspberrypi-power.h>
+#include <soc/bcm2835/raspberrypi-firmware.h>
+
+/*
+ * Firmware indices for the old power domains interface.  Only a few
+ * of them were actually implemented.
+ */
+#define RPI_OLD_POWER_DOMAIN_USB		3
+#define RPI_OLD_POWER_DOMAIN_V3D		10
+
+struct rpi_power_domain {
+	u32 domain;
+	bool enabled;
+	bool old_interface;
+	struct generic_pm_domain base;
+	struct rpi_firmware *fw;
+};
+
+struct rpi_power_domains {
+	bool has_new_interface;
+	struct genpd_onecell_data xlate;
+	struct rpi_firmware *fw;
+	struct rpi_power_domain domains[RPI_POWER_DOMAIN_COUNT];
+};
+
+/*
+ * Packet definition used by RPI_FIRMWARE_SET_POWER_STATE and
+ * RPI_FIRMWARE_SET_DOMAIN_STATE
+ */
+struct rpi_power_domain_packet {
+	u32 domain;
+	u32 on;
+} __packet;
+
+/*
+ * Asks the firmware to enable or disable power on a specific power
+ * domain.
+ */
+static int rpi_firmware_set_power(struct rpi_power_domain *rpi_domain, bool on)
+{
+	struct rpi_power_domain_packet packet;
+
+	packet.domain = rpi_domain->domain;
+	packet.on = on;
+	return rpi_firmware_property(rpi_domain->fw,
+				     rpi_domain->old_interface ?
+				     RPI_FIRMWARE_SET_POWER_STATE :
+				     RPI_FIRMWARE_SET_DOMAIN_STATE,
+				     &packet, sizeof(packet));
+}
+
+static int rpi_domain_off(struct generic_pm_domain *domain)
+{
+	struct rpi_power_domain *rpi_domain =
+		container_of(domain, struct rpi_power_domain, base);
+
+	return rpi_firmware_set_power(rpi_domain, false);
+}
+
+static int rpi_domain_on(struct generic_pm_domain *domain)
+{
+	struct rpi_power_domain *rpi_domain =
+		container_of(domain, struct rpi_power_domain, base);
+
+	return rpi_firmware_set_power(rpi_domain, true);
+}
+
+static void rpi_common_init_power_domain(struct rpi_power_domains *rpi_domains,
+					 int xlate_index, const char *name)
+{
+	struct rpi_power_domain *dom = &rpi_domains->domains[xlate_index];
+
+	dom->fw = rpi_domains->fw;
+
+	dom->base.name = name;
+	dom->base.power_on = rpi_domain_on;
+	dom->base.power_off = rpi_domain_off;
+
+	/*
+	 * Treat all power domains as off at boot.
+	 *
+	 * The firmware itself may be keeping some domains on, but
+	 * from Linux's perspective all we control is the refcounts
+	 * that we give to the firmware, and we can't ask the firmware
+	 * to turn off something that we haven't ourselves turned on.
+	 */
+	pm_genpd_init(&dom->base, NULL, true);
+
+	rpi_domains->xlate.domains[xlate_index] = &dom->base;
+}
+
+static void rpi_init_power_domain(struct rpi_power_domains *rpi_domains,
+				  int xlate_index, const char *name)
+{
+	struct rpi_power_domain *dom = &rpi_domains->domains[xlate_index];
+
+	if (!rpi_domains->has_new_interface)
+		return;
+
+	/* The DT binding index is the firmware's domain index minus one. */
+	dom->domain = xlate_index + 1;
+
+	rpi_common_init_power_domain(rpi_domains, xlate_index, name);
+}
+
+static void rpi_init_old_power_domain(struct rpi_power_domains *rpi_domains,
+				      int xlate_index, int domain,
+				      const char *name)
+{
+	struct rpi_power_domain *dom = &rpi_domains->domains[xlate_index];
+
+	dom->old_interface = true;
+	dom->domain = domain;
+
+	rpi_common_init_power_domain(rpi_domains, xlate_index, name);
+}
+
+/*
+ * Detects whether the firmware supports the new power domains interface.
+ *
+ * The firmware doesn't actually return an error on an unknown tag,
+ * and just skips over it, so we do the detection by putting an
+ * unexpected value in the return field and checking if it was
+ * unchanged.
+ */
+static bool
+rpi_has_new_domain_support(struct rpi_power_domains *rpi_domains)
+{
+	struct rpi_power_domain_packet packet;
+	int ret;
+
+	packet.domain = RPI_POWER_DOMAIN_ARM;
+	packet.on = ~0;
+
+	ret = rpi_firmware_property(rpi_domains->fw,
+				    RPI_FIRMWARE_GET_DOMAIN_STATE,
+				    &packet, sizeof(packet));
+
+	return ret == 0 && packet.on != ~0;
+}
+
+static int rpi_power_probe(struct platform_device *pdev)
+{
+	struct device_node *fw_np;
+	struct device *dev = &pdev->dev;
+	struct rpi_power_domains *rpi_domains;
+
+	rpi_domains = devm_kzalloc(dev, sizeof(*rpi_domains), GFP_KERNEL);
+	if (!rpi_domains)
+		return -ENOMEM;
+
+	rpi_domains->xlate.domains =
+		devm_kzalloc(dev, sizeof(*rpi_domains->xlate.domains) *
+			     RPI_POWER_DOMAIN_COUNT, GFP_KERNEL);
+	if (!rpi_domains->xlate.domains)
+		return -ENOMEM;
+
+	rpi_domains->xlate.num_domains = RPI_POWER_DOMAIN_COUNT;
+
+	fw_np = of_parse_phandle(pdev->dev.of_node, "firmware", 0);
+	if (!fw_np) {
+		dev_err(&pdev->dev, "no firmware node\n");
+		return -ENODEV;
+	}
+
+	rpi_domains->fw = rpi_firmware_get(fw_np);
+	of_node_put(fw_np);
+	if (!rpi_domains->fw)
+		return -EPROBE_DEFER;
+
+	rpi_domains->has_new_interface =
+		rpi_has_new_domain_support(rpi_domains);
+
+	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_I2C0, "I2C0");
+	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_I2C1, "I2C1");
+	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_I2C2, "I2C2");
+	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_VIDEO_SCALER,
+			      "VIDEO_SCALER");
+	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_VPU1, "VPU1");
+	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_HDMI, "HDMI");
+
+	/*
+	 * Use the old firmware interface for USB power, so that we
+	 * can turn it on even if the firmware hasn't been updated.
+	 */
+	rpi_init_old_power_domain(rpi_domains, RPI_POWER_DOMAIN_USB,
+				  RPI_OLD_POWER_DOMAIN_USB, "USB");
+
+	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_VEC, "VEC");
+	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_JPEG, "JPEG");
+	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_H264, "H264");
+	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_V3D, "V3D");
+	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_ISP, "ISP");
+	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_UNICAM0, "UNICAM0");
+	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_UNICAM1, "UNICAM1");
+	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CCP2RX, "CCP2RX");
+	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CSI2, "CSI2");
+	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CPI, "CPI");
+	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_DSI0, "DSI0");
+	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_DSI1, "DSI1");
+	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_TRANSPOSER,
+			      "TRANSPOSER");
+	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CCP2TX, "CCP2TX");
+	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CDP, "CDP");
+	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_ARM, "ARM");
+
+	of_genpd_add_provider_onecell(dev->of_node, &rpi_domains->xlate);
+
+	platform_set_drvdata(pdev, rpi_domains);
+
+	return 0;
+}
+
+static const struct of_device_id rpi_power_of_match[] = {
+	{ .compatible = "raspberrypi,bcm2835-power", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, rpi_power_of_match);
+
+static struct platform_driver rpi_power_driver = {
+	.driver = {
+		.name = "raspberrypi-power",
+		.of_match_table = rpi_power_of_match,
+	},
+	.probe		= rpi_power_probe,
+};
+builtin_platform_driver(rpi_power_driver);
+
+MODULE_AUTHOR("Alexander Aring <aar@pengutronix.de>");
+MODULE_AUTHOR("Eric Anholt <eric@anholt.net>");
+MODULE_DESCRIPTION("Raspberry Pi power domain driver");
+MODULE_LICENSE("GPL v2");