drivers: power: Introduce TI coprocessor driver

All the coprocessors may not be used in all the system usecase scenarios, so we need a driver that can initialize the coprocessors based on the current system usecase. In a scenario where the user knows ahead what's the target OPP for a usecase and which doesnt change during runtime, using devfreq would be an overkill. Introduce a simple driver to configure the initial Operating frequency an dvoltage (OPP) for co processors in a SoC. TI co-processor driver makes use of voltage domain manager for handling the clock frequency changes and corresponding voltage handling thus it can still work seamlessly in a ganged rail scenario where the voltage rails of more than one coprocssor are ganged up. Change-Id: If8c4afba833cf972e080f81c9e02f3126703b96c Signed-off-by: Ravikumar Kattekola <rk@ti.com>

drivers: power: Introduce TI coprocessor driver
All the coprocessors may not be used in all the system usecase scenarios, so we need a driver that can initialize the coprocessors based on the current system usecase. In a scenario where the user knows ahead what's the target OPP for a usecase and which doesnt change during runtime, using devfreq would be an overkill. Introduce a simple driver to configure the initial Operating frequency an dvoltage (OPP) for co processors in a SoC. TI co-processor driver makes use of voltage domain manager for handling the clock frequency changes and corresponding voltage handling thus it can still work seamlessly in a ganged rail scenario where the voltage rails of more than one coprocssor are ganged up. Change-Id: If8c4afba833cf972e080f81c9e02f3126703b96c Signed-off-by: Ravikumar Kattekola <rk@ti.com>
Ravikumar Kattekola · Jacob Stiffler
1 parent 053aa6ec56
Showing 6 changed files with 275 additions and 0 deletions Side-by-side Diff
Documentation/devicetree/bindings/power/coproc/ti-coproc.txt
drivers/power/Kconfig
drivers/power/Makefile
drivers/power/coproc/Kconfig
drivers/power/coproc/Makefile
drivers/power/coproc/ti-coproc.c
+Texas Instruments co-processor driver
+
+A co-processor device is a non-cpu processor found on an SoC.
+
+This document describes the clock and voltage configuration
+used by co-processors/devices typically found on Texas Instrument SoCs.
+
+Required properties
+- compatible: should be
+	"ti,coproc"
+- clocks: <functional clock>, <dpll clock>
+	dpll clock is optional
+- clock-names: "fclk", "dpll"
+	if you change names here, go chnage the driver too
+- clock-target-frequency: Mention your target frequency here
+- operating-points: all OPPs applicable for this device/coprocessor
+- coproc-voltdm: phandle of the Voltage domain associated with this device/coproc
+- voltage-tolerance: Specify a voltage tolerance allowed for this voltage domain
+as per datamanual limits
+
+Example:
+iva_coproc {
+	compatible = "ti,coproc";
+	clocks = <&dpll_iva_m2_ck>, <&dpll_iva_ck>;
+	clock-names = "fclk", "dpll";
+	clock-target-frequency = <532000000>;
+	operating-points = <
+		388200  1055000
+		430000	1150000
+		532000  1250000
+		>;
+	coproc-voltdm = <&voltdm_ivahd>;
+	voltage-tolerance = <1>;
+};
@@ -395,4 +395,5 @@
  
 source "drivers/power/avs/Kconfig"
 source "drivers/power/voltdm/Kconfig"
+source "drivers/power/coproc/Kconfig"
@@ -59,4 +59,5 @@
 obj-$(CONFIG_CHARGER_TPS65090)	+= tps65090-charger.o
 obj-$(CONFIG_POWER_RESET)	+= reset/
 obj-$(CONFIG_VOLTAGE_DOMAIN)	+= voltdm/
+obj-$(CONFIG_TI_COPROC)		+= coproc/
+config TI_COPROC
+	tristate "TI Co-processor driversupport"
+	depends on VOLTAGE_DOMAIN_OMAP
+	help
+		TI Coprocessor driver helps initialize a coprocessor to
+		a particular Operating performance point.
+#Texas Instruments co-processor init driver
+obj-${CONFIG_TI_COPROC}	+= ti-coproc.o
+/*
+ * OMAP SoC COPROC  driver
+ *
+ * Copyright (C) 2014 Texas Instruments Incorporated - http://www.ti.com/
+ *		Carlos Hernandez <ceh@ti.com>
+ *		Nishanth Menon <nm@ti.com>
+ *		Ravikumar Kattekola <rk@ti.com>
+ * 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.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+#include <linux/io.h>
+#include <linux/slab.h>
+#include <linux/mutex.h>
+#include <linux/suspend.h>
+#include <linux/pm_opp.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
+#include <linux/module.h>
+#include <linux/clk.h>
+#include <linux/pm_voltage_domain.h>
+
+/**
+ * struct coproc_data - Co processor private data
+ * @profile:   profile specific for this device
+ * @dev:  device pointer
+ * @:   for this device
+ * @stat: my current statistics
+ * @dev_clk: my device clk
+ * @dpll_clk: my dpll clk
+ * @nb:	my notifier block
+ */
+struct coproc_data {
+	struct device *dev;
+	struct clk *dev_clk;
+	struct clk *dpll_clk;
+	struct notifier_block *clk_nb;
+};
+
+/**
+ * DOC:
+ * clock-names should be defined in dts file, e.g.
+ * coproc {
+ *
+ *  compatible = "ti,coproc";
+ *  clocks = <&dpll_iva_m2_ck>, <&dpll_iva_ck>;
+ *  clock-names = "fclk", "dpll";
+ *  clock-target-frequency = <532000000>;
+ *  operating-points = <
+ *    388200  1055000
+ *    500000  1150000
+ *    532000  1250000
+ *  >;
+ *  coproc-voltdm = <&voltdm_ivahd>;
+ *  voltage-tolerance = <1>;
+ *
+ * };
+ */
+#define DEV_CLK_NAME "fclk"
+#define DPLL_CLK_NAME "dpll"
+
+static int coproc_probe(struct platform_device *pdev)
+{
+	struct coproc_data *d;
+	unsigned int voltage_latency;
+	u32 target_freq = 0;
+	int err = 0;
+	struct device *dev = &pdev->dev;
+	struct device_node *np = of_node_get(dev->of_node);
+	bool noset_dpll_as_rate;
+
+	dev_info(dev, "probe\n");
+
+	of_property_read_u32(np, "clock-target-frequency", &target_freq);
+	if (!target_freq) {
+		dev_err(dev, "%s: Invalid/no target frequency found in dt.\n",
+			__func__);
+		return -EINVAL;
+	}
+
+	noset_dpll_as_rate = of_property_read_bool(np, "noset-dpll-rate");
+
+	d = devm_kzalloc(dev, sizeof(*d), GFP_KERNEL);
+	if (d == NULL) {
+		dev_err(dev, "%s: Cannot allocate memory.\n", __func__);
+		err = -ENOMEM;
+		goto out;
+	}
+	platform_set_drvdata(pdev, d);
+
+	d->dpll_clk = devm_clk_get(dev, DPLL_CLK_NAME);
+	if (IS_ERR(d->dpll_clk)) {
+		err = PTR_ERR(d->dpll_clk);
+		dev_err(dev, "%s: Cannot get dpll clk(%d).\n", __func__, err);
+		d->dpll_clk = NULL;
+	}
+
+	d->dev_clk = devm_clk_get(dev, DEV_CLK_NAME);
+	if (IS_ERR(d->dev_clk)) {
+		err = PTR_ERR(d->dpll_clk);
+		dev_err(dev, "%s: Cannot get func clk(%d).\n", __func__, err);
+		goto out;
+	}
+
+	if (noset_dpll_as_rate)
+		d->dpll_clk = NULL;
+
+	err = of_init_opp_table(dev);
+	if (err) {
+		dev_err(dev, "%s: Cannot initialize opp table(%d).\n", __func__,
+			err);
+		goto out;
+	}
+	d->dev = dev;
+
+	/* Register voltage domain notifier */
+	d->clk_nb = of_pm_voltdm_notifier_register(dev, np, d->dev_clk,
+						   "coproc",
+						   &voltage_latency);
+	if (IS_ERR(d->clk_nb)) {
+		err = PTR_ERR(d->clk_nb);
+		/* defer probe if regulator is not yet registered */
+		if (err == -EPROBE_DEFER) {
+			dev_err(dev,
+				"coproc clock notifier not ready, retry\n");
+		} else {
+			dev_err(dev,
+				"Failed to register coproc clk notifier: %d\n",
+				err);
+		}
+		goto out;
+	}
+
+	if (target_freq) {
+		if (d->dpll_clk) {
+			err = clk_set_rate(d->dpll_clk, target_freq);
+			if (err) {
+				dev_err(dev, "%s: Cannot set dpll clock rate(%d).\n",
+					__func__, err);
+				goto out;
+			}
+		}
+
+		err = clk_set_rate(d->dev_clk, target_freq);
+		if (err) {
+			dev_err(dev, "%s: Cannot set func clock rate(%d).\n",
+				__func__, err);
+			goto out;
+		}
+	}
+
+	/* All good.. */
+	goto out;
+
+out:
+	dev_info(dev, "%s result=%d", __func__, err);
+	return err;
+}
+
+static int coproc_remove(struct platform_device *pdev)
+{
+	struct coproc_data *d = platform_get_drvdata(pdev);
+	struct device *dev = &pdev->dev;
+
+	dev_info(dev, "remove\n");
+
+	of_pm_voltdm_notifier_unregister(d->clk_nb);
+
+	dev_info(dev, "%s Removed\n", __func__);
+	return 0;
+}
+
+/**
+ * coproc_suspend() - dummy hook for suspend
+ * @dev: device pointer
+ *
+ * Return: 0
+ */
+static int coproc_suspend(struct device *dev)
+{
+	dev_info(dev, "suspend\n");
+	return 0;
+}
+
+/**
+ * coproc_resume() - dummy hook for resume
+ * @dev: device pointer
+ *
+ * Return: 0
+ */
+static int coproc_resume(struct device *dev)
+{
+	dev_info(dev, "resume\n");
+	return 0;
+}
+
+/* Device power management hooks */
+static SIMPLE_DEV_PM_OPS(coproc_pm,
+			 coproc_suspend,
+			 coproc_resume);
+
+static struct of_device_id of_coproc_match[] = {
+	{.compatible = "ti,coproc"},
+	{},
+};
+
+MODULE_DEVICE_TABLE(of, of_coproc_match);
+
+static struct platform_driver coproc_driver = {
+	.probe = coproc_probe,
+	.remove = coproc_remove,
+	.driver = {
+		   .name = "coproc",
+		   .owner = THIS_MODULE,
+		   .of_match_table = of_match_ptr(of_coproc_match),
+		   .pm = &coproc_pm,
+		   },
+};
+module_platform_driver(coproc_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("OMAP Co-processor Driver");
+MODULE_AUTHOR("Texas Instruments Inc.");
	1	+Texas Instruments co-processor driver
	2	+
	3	+A co-processor device is a non-cpu processor found on an SoC.
	4	+
	5	+This document describes the clock and voltage configuration
	6	+used by co-processors/devices typically found on Texas Instrument SoCs.
	7	+
	8	+Required properties
	9	+- compatible: should be
	10	+ "ti,coproc"
	11	+- clocks: <functional clock>, <dpll clock>
	12	+ dpll clock is optional
	13	+- clock-names: "fclk", "dpll"
	14	+ if you change names here, go chnage the driver too
	15	+- clock-target-frequency: Mention your target frequency here
	16	+- operating-points: all OPPs applicable for this device/coprocessor
	17	+- coproc-voltdm: phandle of the Voltage domain associated with this device/coproc
	18	+- voltage-tolerance: Specify a voltage tolerance allowed for this voltage domain
	19	+as per datamanual limits
	20	+
	21	+Example:
	22	+iva_coproc {
	23	+ compatible = "ti,coproc";
	24	+ clocks = <&dpll_iva_m2_ck>, <&dpll_iva_ck>;
	25	+ clock-names = "fclk", "dpll";
	26	+ clock-target-frequency = <532000000>;
	27	+ operating-points = <
	28	+ 388200 1055000
	29	+ 430000 1150000
	30	+ 532000 1250000
	31	+ >;
	32	+ coproc-voltdm = <&voltdm_ivahd>;
	33	+ voltage-tolerance = <1>;
	34	+};
...	...	@@ -395,4 +395,5 @@
395	395
396	396	source "drivers/power/avs/Kconfig"
397	397	source "drivers/power/voltdm/Kconfig"
	398	+source "drivers/power/coproc/Kconfig"
...	...	@@ -59,4 +59,5 @@
59	59	obj-$(CONFIG_CHARGER_TPS65090) += tps65090-charger.o
60	60	obj-$(CONFIG_POWER_RESET) += reset/
61	61	obj-$(CONFIG_VOLTAGE_DOMAIN) += voltdm/
	62	+obj-$(CONFIG_TI_COPROC) += coproc/
	1	+config TI_COPROC
	2	+ tristate "TI Co-processor driversupport"
	3	+ depends on VOLTAGE_DOMAIN_OMAP
	4	+ help
	5	+ TI Coprocessor driver helps initialize a coprocessor to
	6	+ a particular Operating performance point.
	1	+#Texas Instruments co-processor init driver
	2	+obj-${CONFIG_TI_COPROC} += ti-coproc.o
	1	+/*
	2	+ * OMAP SoC COPROC driver
	3	+ *
	4	+ * Copyright (C) 2014 Texas Instruments Incorporated - http://www.ti.com/
	5	+ * Carlos Hernandez <ceh@ti.com>
	6	+ * Nishanth Menon <nm@ti.com>
	7	+ * Ravikumar Kattekola <rk@ti.com>
	8	+ * This program is free software; you can redistribute it and/or modify
	9	+ * it under the terms of the GNU General Public License version 2 as
	10	+ * published by the Free Software Foundation.
	11	+ *
	12	+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
	13	+ * kind, whether express or implied; without even the implied warranty
	14	+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	15	+ * GNU General Public License for more details.
	16	+ */
	17	+#include <linux/io.h>
	18	+#include <linux/slab.h>
	19	+#include <linux/mutex.h>
	20	+#include <linux/suspend.h>
	21	+#include <linux/pm_opp.h>
	22	+#include <linux/of.h>
	23	+#include <linux/platform_device.h>
	24	+#include <linux/regulator/consumer.h>
	25	+#include <linux/module.h>
	26	+#include <linux/clk.h>
	27	+#include <linux/pm_voltage_domain.h>
	28	+
	29	+/**
	30	+ * struct coproc_data - Co processor private data
	31	+ * @profile: profile specific for this device
	32	+ * @dev: device pointer
	33	+ * @: for this device
	34	+ * @stat: my current statistics
	35	+ * @dev_clk: my device clk
	36	+ * @dpll_clk: my dpll clk
	37	+ * @nb: my notifier block
	38	+ */
	39	+struct coproc_data {
	40	+ struct device *dev;
	41	+ struct clk *dev_clk;
	42	+ struct clk *dpll_clk;
	43	+ struct notifier_block *clk_nb;
	44	+};
	45	+
	46	+/**
	47	+ * DOC:
	48	+ * clock-names should be defined in dts file, e.g.
	49	+ * coproc {
	50	+ *
	51	+ * compatible = "ti,coproc";
	52	+ * clocks = <&dpll_iva_m2_ck>, <&dpll_iva_ck>;
	53	+ * clock-names = "fclk", "dpll";
	54	+ * clock-target-frequency = <532000000>;
	55	+ * operating-points = <
	56	+ * 388200 1055000
	57	+ * 500000 1150000
	58	+ * 532000 1250000
	59	+ * >;
	60	+ * coproc-voltdm = <&voltdm_ivahd>;
	61	+ * voltage-tolerance = <1>;
	62	+ *
	63	+ * };
	64	+ */
	65	+#define DEV_CLK_NAME "fclk"
	66	+#define DPLL_CLK_NAME "dpll"
	67	+
	68	+static int coproc_probe(struct platform_device *pdev)
	69	+{
	70	+ struct coproc_data *d;
	71	+ unsigned int voltage_latency;
	72	+ u32 target_freq = 0;
	73	+ int err = 0;
	74	+ struct device *dev = &pdev->dev;
	75	+ struct device_node *np = of_node_get(dev->of_node);
	76	+ bool noset_dpll_as_rate;
	77	+
	78	+ dev_info(dev, "probe\n");
	79	+
	80	+ of_property_read_u32(np, "clock-target-frequency", &target_freq);
	81	+ if (!target_freq) {
	82	+ dev_err(dev, "%s: Invalid/no target frequency found in dt.\n",
	83	+ __func__);
	84	+ return -EINVAL;
	85	+ }
	86	+
	87	+ noset_dpll_as_rate = of_property_read_bool(np, "noset-dpll-rate");
	88	+
	89	+ d = devm_kzalloc(dev, sizeof(*d), GFP_KERNEL);
	90	+ if (d == NULL) {
	91	+ dev_err(dev, "%s: Cannot allocate memory.\n", __func__);
	92	+ err = -ENOMEM;
	93	+ goto out;
	94	+ }
	95	+ platform_set_drvdata(pdev, d);
	96	+
	97	+ d->dpll_clk = devm_clk_get(dev, DPLL_CLK_NAME);
	98	+ if (IS_ERR(d->dpll_clk)) {
	99	+ err = PTR_ERR(d->dpll_clk);
	100	+ dev_err(dev, "%s: Cannot get dpll clk(%d).\n", __func__, err);
	101	+ d->dpll_clk = NULL;
	102	+ }
	103	+
	104	+ d->dev_clk = devm_clk_get(dev, DEV_CLK_NAME);
	105	+ if (IS_ERR(d->dev_clk)) {
	106	+ err = PTR_ERR(d->dpll_clk);
	107	+ dev_err(dev, "%s: Cannot get func clk(%d).\n", __func__, err);
	108	+ goto out;
	109	+ }
	110	+
	111	+ if (noset_dpll_as_rate)
	112	+ d->dpll_clk = NULL;
	113	+
	114	+ err = of_init_opp_table(dev);
	115	+ if (err) {
	116	+ dev_err(dev, "%s: Cannot initialize opp table(%d).\n", __func__,
	117	+ err);
	118	+ goto out;
	119	+ }
	120	+ d->dev = dev;
	121	+
	122	+ /* Register voltage domain notifier */
	123	+ d->clk_nb = of_pm_voltdm_notifier_register(dev, np, d->dev_clk,
	124	+ "coproc",
	125	+ &voltage_latency);
	126	+ if (IS_ERR(d->clk_nb)) {
	127	+ err = PTR_ERR(d->clk_nb);
	128	+ /* defer probe if regulator is not yet registered */
	129	+ if (err == -EPROBE_DEFER) {
	130	+ dev_err(dev,
	131	+ "coproc clock notifier not ready, retry\n");
	132	+ } else {
	133	+ dev_err(dev,
	134	+ "Failed to register coproc clk notifier: %d\n",
	135	+ err);
	136	+ }
	137	+ goto out;
	138	+ }
	139	+
	140	+ if (target_freq) {
	141	+ if (d->dpll_clk) {
	142	+ err = clk_set_rate(d->dpll_clk, target_freq);
	143	+ if (err) {
	144	+ dev_err(dev, "%s: Cannot set dpll clock rate(%d).\n",
	145	+ __func__, err);
	146	+ goto out;
	147	+ }
	148	+ }
	149	+
	150	+ err = clk_set_rate(d->dev_clk, target_freq);
	151	+ if (err) {
	152	+ dev_err(dev, "%s: Cannot set func clock rate(%d).\n",
	153	+ __func__, err);
	154	+ goto out;
	155	+ }
	156	+ }
	157	+
	158	+ /* All good.. */
	159	+ goto out;
	160	+
	161	+out:
	162	+ dev_info(dev, "%s result=%d", __func__, err);
	163	+ return err;
	164	+}
	165	+
	166	+static int coproc_remove(struct platform_device *pdev)
	167	+{
	168	+ struct coproc_data *d = platform_get_drvdata(pdev);
	169	+ struct device *dev = &pdev->dev;
	170	+
	171	+ dev_info(dev, "remove\n");
	172	+
	173	+ of_pm_voltdm_notifier_unregister(d->clk_nb);
	174	+
	175	+ dev_info(dev, "%s Removed\n", __func__);
	176	+ return 0;
	177	+}
	178	+
	179	+/**
	180	+ * coproc_suspend() - dummy hook for suspend
	181	+ * @dev: device pointer
	182	+ *
	183	+ * Return: 0
	184	+ */
	185	+static int coproc_suspend(struct device *dev)
	186	+{
	187	+ dev_info(dev, "suspend\n");
	188	+ return 0;
	189	+}
	190	+
	191	+/**
	192	+ * coproc_resume() - dummy hook for resume
	193	+ * @dev: device pointer
	194	+ *
	195	+ * Return: 0
	196	+ */
	197	+static int coproc_resume(struct device *dev)
	198	+{
	199	+ dev_info(dev, "resume\n");
	200	+ return 0;
	201	+}
	202	+
	203	+/* Device power management hooks */
	204	+static SIMPLE_DEV_PM_OPS(coproc_pm,
	205	+ coproc_suspend,
	206	+ coproc_resume);
	207	+
	208	+static struct of_device_id of_coproc_match[] = {
	209	+ {.compatible = "ti,coproc"},
	210	+ {},
	211	+};
	212	+
	213	+MODULE_DEVICE_TABLE(of, of_coproc_match);
	214	+
	215	+static struct platform_driver coproc_driver = {
	216	+ .probe = coproc_probe,
	217	+ .remove = coproc_remove,
	218	+ .driver = {
	219	+ .name = "coproc",
	220	+ .owner = THIS_MODULE,
	221	+ .of_match_table = of_match_ptr(of_coproc_match),
	222	+ .pm = &coproc_pm,
	223	+ },
	224	+};
	225	+module_platform_driver(coproc_driver);
	226	+
	227	+MODULE_LICENSE("GPL v2");
	228	+MODULE_DESCRIPTION("OMAP Co-processor Driver");
	229	+MODULE_AUTHOR("Texas Instruments Inc.");