raspberrypi-power.c

  1// SPDX-License-Identifier: GPL-2.0
  2/* (C) 2015 Pengutronix, Alexander Aring <aar@pengutronix.de>
  3 *
  4 * Authors:
  5 * Alexander Aring <aar@pengutronix.de>
  6 * Eric Anholt <eric@anholt.net>
  7 */
  8
  9#include <linux/module.h>
 10#include <linux/of.h>
 11#include <linux/platform_device.h>
 12#include <linux/pm_domain.h>
 13#include <dt-bindings/power/raspberrypi-power.h>
 14#include <soc/bcm2835/raspberrypi-firmware.h>
 15
 16/*
 17 * Firmware indices for the old power domains interface.  Only a few
 18 * of them were actually implemented.
 19 */
 20#define RPI_OLD_POWER_DOMAIN_USB		3
 21#define RPI_OLD_POWER_DOMAIN_V3D		10
 22
 23struct rpi_power_domain {
 24	u32 domain;
 25	bool enabled;
 26	bool old_interface;
 27	struct generic_pm_domain base;
 28	struct rpi_firmware *fw;
 29};
 30
 31struct rpi_power_domains {
 32	bool has_new_interface;
 33	struct genpd_onecell_data xlate;
 34	struct rpi_firmware *fw;
 35	struct rpi_power_domain domains[RPI_POWER_DOMAIN_COUNT];
 36};
 37
 38/*
 39 * Packet definition used by RPI_FIRMWARE_SET_POWER_STATE and
 40 * RPI_FIRMWARE_SET_DOMAIN_STATE
 41 */
 42struct rpi_power_domain_packet {
 43	u32 domain;
 44	u32 state;
 45};
 46
 47/*
 48 * Asks the firmware to enable or disable power on a specific power
 49 * domain.
 50 */
 51static int rpi_firmware_set_power(struct generic_pm_domain *domain, bool on)
 52{
 53	struct rpi_power_domain *rpi_domain =
 54		container_of(domain, struct rpi_power_domain, base);
 55	bool old_interface = rpi_domain->old_interface;
 56	struct rpi_power_domain_packet packet;
 57	int ret;
 58
 59	packet.domain = rpi_domain->domain;
 60	packet.state = on;
 61
 62	ret = rpi_firmware_property(rpi_domain->fw, old_interface ?
 63				    RPI_FIRMWARE_SET_POWER_STATE :
 64				    RPI_FIRMWARE_SET_DOMAIN_STATE,
 65				    &packet, sizeof(packet));
 66	if (ret)
 67		dev_err(&domain->dev, "Failed to set %s to %u (%d)\n",
 68			old_interface ? "power" : "domain", on, ret);
 69	else
 70		dev_dbg(&domain->dev, "Set %s to %u\n",
 71			old_interface ? "power" : "domain", on);
 72
 73	return ret;
 74}
 75
 76static int rpi_domain_off(struct generic_pm_domain *domain)
 77{
 78	return rpi_firmware_set_power(domain, false);
 79}
 80
 81static int rpi_domain_on(struct generic_pm_domain *domain)
 82{
 83	return rpi_firmware_set_power(domain, true);
 84}
 85
 86static void rpi_common_init_power_domain(struct rpi_power_domains *rpi_domains,
 87					 int xlate_index, const char *name)
 88{
 89	struct rpi_power_domain *dom = &rpi_domains->domains[xlate_index];
 90
 91	dom->fw = rpi_domains->fw;
 92
 93	dom->base.name = name;
 94	dom->base.flags = GENPD_FLAG_ACTIVE_WAKEUP;
 95	dom->base.power_on = rpi_domain_on;
 96	dom->base.power_off = rpi_domain_off;
 97
 98	/*
 99	 * Treat all power domains as off at boot.
100	 *
101	 * The firmware itself may be keeping some domains on, but
102	 * from Linux's perspective all we control is the refcounts
103	 * that we give to the firmware, and we can't ask the firmware
104	 * to turn off something that we haven't ourselves turned on.
105	 */
106	pm_genpd_init(&dom->base, NULL, true);
107
108	rpi_domains->xlate.domains[xlate_index] = &dom->base;
109}
110
111static void rpi_init_power_domain(struct rpi_power_domains *rpi_domains,
112				  int xlate_index, const char *name)
113{
114	struct rpi_power_domain *dom = &rpi_domains->domains[xlate_index];
115
116	if (!rpi_domains->has_new_interface)
117		return;
118
119	/* The DT binding index is the firmware's domain index minus one. */
120	dom->domain = xlate_index + 1;
121
122	rpi_common_init_power_domain(rpi_domains, xlate_index, name);
123}
124
125static void rpi_init_old_power_domain(struct rpi_power_domains *rpi_domains,
126				      int xlate_index, int domain,
127				      const char *name)
128{
129	struct rpi_power_domain *dom = &rpi_domains->domains[xlate_index];
130
131	dom->old_interface = true;
132	dom->domain = domain;
133
134	rpi_common_init_power_domain(rpi_domains, xlate_index, name);
135}
136
137/*
138 * Detects whether the firmware supports the new power domains interface.
139 *
140 * The firmware doesn't actually return an error on an unknown tag,
141 * and just skips over it, so we do the detection by putting an
142 * unexpected value in the return field and checking if it was
143 * unchanged.
144 */
145static bool
146rpi_has_new_domain_support(struct rpi_power_domains *rpi_domains)
147{
148	struct rpi_power_domain_packet packet;
149	int ret;
150
151	packet.domain = RPI_POWER_DOMAIN_ARM;
152	packet.state = ~0;
153
154	ret = rpi_firmware_property(rpi_domains->fw,
155				    RPI_FIRMWARE_GET_DOMAIN_STATE,
156				    &packet, sizeof(packet));
157
158	return ret == 0 && packet.state != ~0;
159}
160
161static int rpi_power_probe(struct platform_device *pdev)
162{
163	struct device_node *fw_np;
164	struct device *dev = &pdev->dev;
165	struct rpi_power_domains *rpi_domains;
166
167	rpi_domains = devm_kzalloc(dev, sizeof(*rpi_domains), GFP_KERNEL);
168	if (!rpi_domains)
169		return -ENOMEM;
170
171	rpi_domains->xlate.domains =
172		devm_kcalloc(dev,
173			     RPI_POWER_DOMAIN_COUNT,
174			     sizeof(*rpi_domains->xlate.domains),
175			     GFP_KERNEL);
176	if (!rpi_domains->xlate.domains)
177		return -ENOMEM;
178
179	rpi_domains->xlate.num_domains = RPI_POWER_DOMAIN_COUNT;
180
181	fw_np = of_parse_phandle(pdev->dev.of_node, "firmware", 0);
182	if (!fw_np) {
183		dev_err(&pdev->dev, "no firmware node\n");
184		return -ENODEV;
185	}
186
187	rpi_domains->fw = devm_rpi_firmware_get(&pdev->dev, fw_np);
188	of_node_put(fw_np);
189	if (!rpi_domains->fw)
190		return -EPROBE_DEFER;
191
192	rpi_domains->has_new_interface =
193		rpi_has_new_domain_support(rpi_domains);
194
195	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_I2C0, "I2C0");
196	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_I2C1, "I2C1");
197	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_I2C2, "I2C2");
198	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_VIDEO_SCALER,
199			      "VIDEO_SCALER");
200	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_VPU1, "VPU1");
201	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_HDMI, "HDMI");
202
203	/*
204	 * Use the old firmware interface for USB power, so that we
205	 * can turn it on even if the firmware hasn't been updated.
206	 */
207	rpi_init_old_power_domain(rpi_domains, RPI_POWER_DOMAIN_USB,
208				  RPI_OLD_POWER_DOMAIN_USB, "USB");
209
210	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_VEC, "VEC");
211	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_JPEG, "JPEG");
212	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_H264, "H264");
213	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_V3D, "V3D");
214	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_ISP, "ISP");
215	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_UNICAM0, "UNICAM0");
216	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_UNICAM1, "UNICAM1");
217	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CCP2RX, "CCP2RX");
218	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CSI2, "CSI2");
219	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CPI, "CPI");
220	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_DSI0, "DSI0");
221	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_DSI1, "DSI1");
222	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_TRANSPOSER,
223			      "TRANSPOSER");
224	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CCP2TX, "CCP2TX");
225	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CDP, "CDP");
226	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_ARM, "ARM");
227
228	of_genpd_add_provider_onecell(dev->of_node, &rpi_domains->xlate);
229
230	platform_set_drvdata(pdev, rpi_domains);
231
232	return 0;
233}
234
235static const struct of_device_id rpi_power_of_match[] = {
236	{ .compatible = "raspberrypi,bcm2835-power", },
237	{},
238};
239MODULE_DEVICE_TABLE(of, rpi_power_of_match);
240
241static struct platform_driver rpi_power_driver = {
242	.driver = {
243		.name = "raspberrypi-power",
244		.of_match_table = rpi_power_of_match,
245	},
246	.probe		= rpi_power_probe,
247};
248builtin_platform_driver(rpi_power_driver);
249
250MODULE_AUTHOR("Alexander Aring <aar@pengutronix.de>");
251MODULE_AUTHOR("Eric Anholt <eric@anholt.net>");
252MODULE_DESCRIPTION("Raspberry Pi power domain driver");