1*65c8a798SAndreas Dannenberg // SPDX-License-Identifier: GPL-2.0+
2*65c8a798SAndreas Dannenberg /*
3*65c8a798SAndreas Dannenberg * Texas Instruments System Control Interface (TI SCI) reset driver
4*65c8a798SAndreas Dannenberg *
5*65c8a798SAndreas Dannenberg * Copyright (C) 2018 Texas Instruments Incorporated - http://www.ti.com/
6*65c8a798SAndreas Dannenberg * Andreas Dannenberg <dannenberg@ti.com>
7*65c8a798SAndreas Dannenberg *
8*65c8a798SAndreas Dannenberg * Loosely based on Linux kernel reset-ti-sci.c...
9*65c8a798SAndreas Dannenberg */
10*65c8a798SAndreas Dannenberg
11*65c8a798SAndreas Dannenberg #include <common.h>
12*65c8a798SAndreas Dannenberg #include <dm.h>
13*65c8a798SAndreas Dannenberg #include <errno.h>
14*65c8a798SAndreas Dannenberg #include <reset-uclass.h>
15*65c8a798SAndreas Dannenberg #include <linux/soc/ti/ti_sci_protocol.h>
16*65c8a798SAndreas Dannenberg
17*65c8a798SAndreas Dannenberg /**
18*65c8a798SAndreas Dannenberg * struct ti_sci_reset_data - reset controller information structure
19*65c8a798SAndreas Dannenberg * @sci: TI SCI handle used for communication with system controller
20*65c8a798SAndreas Dannenberg */
21*65c8a798SAndreas Dannenberg struct ti_sci_reset_data {
22*65c8a798SAndreas Dannenberg const struct ti_sci_handle *sci;
23*65c8a798SAndreas Dannenberg };
24*65c8a798SAndreas Dannenberg
ti_sci_reset_probe(struct udevice * dev)25*65c8a798SAndreas Dannenberg static int ti_sci_reset_probe(struct udevice *dev)
26*65c8a798SAndreas Dannenberg {
27*65c8a798SAndreas Dannenberg struct ti_sci_reset_data *data = dev_get_priv(dev);
28*65c8a798SAndreas Dannenberg
29*65c8a798SAndreas Dannenberg debug("%s(dev=%p)\n", __func__, dev);
30*65c8a798SAndreas Dannenberg
31*65c8a798SAndreas Dannenberg if (!data)
32*65c8a798SAndreas Dannenberg return -ENOMEM;
33*65c8a798SAndreas Dannenberg
34*65c8a798SAndreas Dannenberg /* Store handle for communication with the system controller */
35*65c8a798SAndreas Dannenberg data->sci = ti_sci_get_handle(dev);
36*65c8a798SAndreas Dannenberg if (IS_ERR(data->sci))
37*65c8a798SAndreas Dannenberg return PTR_ERR(data->sci);
38*65c8a798SAndreas Dannenberg
39*65c8a798SAndreas Dannenberg return 0;
40*65c8a798SAndreas Dannenberg }
41*65c8a798SAndreas Dannenberg
ti_sci_reset_of_xlate(struct reset_ctl * rst,struct ofnode_phandle_args * args)42*65c8a798SAndreas Dannenberg static int ti_sci_reset_of_xlate(struct reset_ctl *rst,
43*65c8a798SAndreas Dannenberg struct ofnode_phandle_args *args)
44*65c8a798SAndreas Dannenberg {
45*65c8a798SAndreas Dannenberg debug("%s(rst=%p, args_count=%d)\n", __func__, rst, args->args_count);
46*65c8a798SAndreas Dannenberg
47*65c8a798SAndreas Dannenberg if (args->args_count != 2) {
48*65c8a798SAndreas Dannenberg debug("Invalid args_count: %d\n", args->args_count);
49*65c8a798SAndreas Dannenberg return -EINVAL;
50*65c8a798SAndreas Dannenberg }
51*65c8a798SAndreas Dannenberg
52*65c8a798SAndreas Dannenberg /*
53*65c8a798SAndreas Dannenberg * On TI SCI-based devices, the reset provider id field is used as a
54*65c8a798SAndreas Dannenberg * device ID, and the data field is used as the associated reset mask.
55*65c8a798SAndreas Dannenberg */
56*65c8a798SAndreas Dannenberg rst->id = args->args[0];
57*65c8a798SAndreas Dannenberg rst->data = args->args[1];
58*65c8a798SAndreas Dannenberg
59*65c8a798SAndreas Dannenberg return 0;
60*65c8a798SAndreas Dannenberg }
61*65c8a798SAndreas Dannenberg
ti_sci_reset_request(struct reset_ctl * rst)62*65c8a798SAndreas Dannenberg static int ti_sci_reset_request(struct reset_ctl *rst)
63*65c8a798SAndreas Dannenberg {
64*65c8a798SAndreas Dannenberg debug("%s(rst=%p)\n", __func__, rst);
65*65c8a798SAndreas Dannenberg return 0;
66*65c8a798SAndreas Dannenberg }
67*65c8a798SAndreas Dannenberg
ti_sci_reset_free(struct reset_ctl * rst)68*65c8a798SAndreas Dannenberg static int ti_sci_reset_free(struct reset_ctl *rst)
69*65c8a798SAndreas Dannenberg {
70*65c8a798SAndreas Dannenberg debug("%s(rst=%p)\n", __func__, rst);
71*65c8a798SAndreas Dannenberg return 0;
72*65c8a798SAndreas Dannenberg }
73*65c8a798SAndreas Dannenberg
74*65c8a798SAndreas Dannenberg /**
75*65c8a798SAndreas Dannenberg * ti_sci_reset_set() - program a device's reset
76*65c8a798SAndreas Dannenberg * @rst: Handle to a single reset signal
77*65c8a798SAndreas Dannenberg * @assert: boolean flag to indicate assert or deassert
78*65c8a798SAndreas Dannenberg *
79*65c8a798SAndreas Dannenberg * This is a common internal function used to assert or deassert a device's
80*65c8a798SAndreas Dannenberg * reset using the TI SCI protocol. The device's reset is asserted if the
81*65c8a798SAndreas Dannenberg * @assert argument is true, or deasserted if @assert argument is false.
82*65c8a798SAndreas Dannenberg * The mechanism itself is a read-modify-write procedure, the current device
83*65c8a798SAndreas Dannenberg * reset register is read using a TI SCI device operation, the new value is
84*65c8a798SAndreas Dannenberg * set or un-set using the reset's mask, and the new reset value written by
85*65c8a798SAndreas Dannenberg * using another TI SCI device operation.
86*65c8a798SAndreas Dannenberg *
87*65c8a798SAndreas Dannenberg * Return: 0 for successful request, else a corresponding error value
88*65c8a798SAndreas Dannenberg */
ti_sci_reset_set(struct reset_ctl * rst,bool assert)89*65c8a798SAndreas Dannenberg static int ti_sci_reset_set(struct reset_ctl *rst, bool assert)
90*65c8a798SAndreas Dannenberg {
91*65c8a798SAndreas Dannenberg struct ti_sci_reset_data *data = dev_get_priv(rst->dev);
92*65c8a798SAndreas Dannenberg const struct ti_sci_handle *sci = data->sci;
93*65c8a798SAndreas Dannenberg const struct ti_sci_dev_ops *dops = &sci->ops.dev_ops;
94*65c8a798SAndreas Dannenberg u32 reset_state;
95*65c8a798SAndreas Dannenberg int ret;
96*65c8a798SAndreas Dannenberg
97*65c8a798SAndreas Dannenberg ret = dops->get_device_resets(sci, rst->id, &reset_state);
98*65c8a798SAndreas Dannenberg if (ret) {
99*65c8a798SAndreas Dannenberg dev_err(rst->dev, "%s: get_device_resets failed (%d)\n",
100*65c8a798SAndreas Dannenberg __func__, ret);
101*65c8a798SAndreas Dannenberg return ret;
102*65c8a798SAndreas Dannenberg }
103*65c8a798SAndreas Dannenberg
104*65c8a798SAndreas Dannenberg if (assert)
105*65c8a798SAndreas Dannenberg reset_state |= rst->data;
106*65c8a798SAndreas Dannenberg else
107*65c8a798SAndreas Dannenberg reset_state &= ~rst->data;
108*65c8a798SAndreas Dannenberg
109*65c8a798SAndreas Dannenberg ret = dops->set_device_resets(sci, rst->id, reset_state);
110*65c8a798SAndreas Dannenberg if (ret) {
111*65c8a798SAndreas Dannenberg dev_err(rst->dev, "%s: set_device_resets failed (%d)\n",
112*65c8a798SAndreas Dannenberg __func__, ret);
113*65c8a798SAndreas Dannenberg return ret;
114*65c8a798SAndreas Dannenberg }
115*65c8a798SAndreas Dannenberg
116*65c8a798SAndreas Dannenberg return 0;
117*65c8a798SAndreas Dannenberg }
118*65c8a798SAndreas Dannenberg
119*65c8a798SAndreas Dannenberg /**
120*65c8a798SAndreas Dannenberg * ti_sci_reset_assert() - assert device reset
121*65c8a798SAndreas Dannenberg * @rst: Handle to a single reset signal
122*65c8a798SAndreas Dannenberg *
123*65c8a798SAndreas Dannenberg * This function implements the reset driver op to assert a device's reset
124*65c8a798SAndreas Dannenberg * using the TI SCI protocol. This invokes the function ti_sci_reset_set()
125*65c8a798SAndreas Dannenberg * with the corresponding parameters as passed in, but with the @assert
126*65c8a798SAndreas Dannenberg * argument set to true for asserting the reset.
127*65c8a798SAndreas Dannenberg *
128*65c8a798SAndreas Dannenberg * Return: 0 for successful request, else a corresponding error value
129*65c8a798SAndreas Dannenberg */
ti_sci_reset_assert(struct reset_ctl * rst)130*65c8a798SAndreas Dannenberg static int ti_sci_reset_assert(struct reset_ctl *rst)
131*65c8a798SAndreas Dannenberg {
132*65c8a798SAndreas Dannenberg debug("%s(rst=%p)\n", __func__, rst);
133*65c8a798SAndreas Dannenberg return ti_sci_reset_set(rst, true);
134*65c8a798SAndreas Dannenberg }
135*65c8a798SAndreas Dannenberg
136*65c8a798SAndreas Dannenberg /**
137*65c8a798SAndreas Dannenberg * ti_sci_reset_deassert() - deassert device reset
138*65c8a798SAndreas Dannenberg * @rst: Handle to a single reset signal
139*65c8a798SAndreas Dannenberg *
140*65c8a798SAndreas Dannenberg * This function implements the reset driver op to deassert a device's reset
141*65c8a798SAndreas Dannenberg * using the TI SCI protocol. This invokes the function ti_sci_reset_set()
142*65c8a798SAndreas Dannenberg * with the corresponding parameters as passed in, but with the @assert
143*65c8a798SAndreas Dannenberg * argument set to false for deasserting the reset.
144*65c8a798SAndreas Dannenberg *
145*65c8a798SAndreas Dannenberg * Return: 0 for successful request, else a corresponding error value
146*65c8a798SAndreas Dannenberg */
ti_sci_reset_deassert(struct reset_ctl * rst)147*65c8a798SAndreas Dannenberg static int ti_sci_reset_deassert(struct reset_ctl *rst)
148*65c8a798SAndreas Dannenberg {
149*65c8a798SAndreas Dannenberg debug("%s(rst=%p)\n", __func__, rst);
150*65c8a798SAndreas Dannenberg return ti_sci_reset_set(rst, false);
151*65c8a798SAndreas Dannenberg }
152*65c8a798SAndreas Dannenberg
153*65c8a798SAndreas Dannenberg /**
154*65c8a798SAndreas Dannenberg * ti_sci_reset_status() - check device reset status
155*65c8a798SAndreas Dannenberg * @rst: Handle to a single reset signal
156*65c8a798SAndreas Dannenberg *
157*65c8a798SAndreas Dannenberg * This function implements the reset driver op to return the status of a
158*65c8a798SAndreas Dannenberg * device's reset using the TI SCI protocol. The reset register value is read
159*65c8a798SAndreas Dannenberg * by invoking the TI SCI device operation .get_device_resets(), and the
160*65c8a798SAndreas Dannenberg * status of the specific reset is extracted and returned using this reset's
161*65c8a798SAndreas Dannenberg * reset mask.
162*65c8a798SAndreas Dannenberg *
163*65c8a798SAndreas Dannenberg * Return: 0 if reset is deasserted, or a non-zero value if reset is asserted
164*65c8a798SAndreas Dannenberg */
ti_sci_reset_status(struct reset_ctl * rst)165*65c8a798SAndreas Dannenberg static int ti_sci_reset_status(struct reset_ctl *rst)
166*65c8a798SAndreas Dannenberg {
167*65c8a798SAndreas Dannenberg struct ti_sci_reset_data *data = dev_get_priv(rst->dev);
168*65c8a798SAndreas Dannenberg const struct ti_sci_handle *sci = data->sci;
169*65c8a798SAndreas Dannenberg const struct ti_sci_dev_ops *dops = &sci->ops.dev_ops;
170*65c8a798SAndreas Dannenberg u32 reset_state;
171*65c8a798SAndreas Dannenberg int ret;
172*65c8a798SAndreas Dannenberg
173*65c8a798SAndreas Dannenberg debug("%s(rst=%p)\n", __func__, rst);
174*65c8a798SAndreas Dannenberg
175*65c8a798SAndreas Dannenberg ret = dops->get_device_resets(sci, rst->id, &reset_state);
176*65c8a798SAndreas Dannenberg if (ret) {
177*65c8a798SAndreas Dannenberg dev_err(rst->dev, "%s: get_device_resets failed (%d)\n",
178*65c8a798SAndreas Dannenberg __func__, ret);
179*65c8a798SAndreas Dannenberg return ret;
180*65c8a798SAndreas Dannenberg }
181*65c8a798SAndreas Dannenberg
182*65c8a798SAndreas Dannenberg return reset_state & rst->data;
183*65c8a798SAndreas Dannenberg }
184*65c8a798SAndreas Dannenberg
185*65c8a798SAndreas Dannenberg static const struct udevice_id ti_sci_reset_of_match[] = {
186*65c8a798SAndreas Dannenberg { .compatible = "ti,sci-reset", },
187*65c8a798SAndreas Dannenberg { /* sentinel */ },
188*65c8a798SAndreas Dannenberg };
189*65c8a798SAndreas Dannenberg
190*65c8a798SAndreas Dannenberg static struct reset_ops ti_sci_reset_ops = {
191*65c8a798SAndreas Dannenberg .of_xlate = ti_sci_reset_of_xlate,
192*65c8a798SAndreas Dannenberg .request = ti_sci_reset_request,
193*65c8a798SAndreas Dannenberg .free = ti_sci_reset_free,
194*65c8a798SAndreas Dannenberg .rst_assert = ti_sci_reset_assert,
195*65c8a798SAndreas Dannenberg .rst_deassert = ti_sci_reset_deassert,
196*65c8a798SAndreas Dannenberg .rst_status = ti_sci_reset_status,
197*65c8a798SAndreas Dannenberg };
198*65c8a798SAndreas Dannenberg
199*65c8a798SAndreas Dannenberg U_BOOT_DRIVER(ti_sci_reset) = {
200*65c8a798SAndreas Dannenberg .name = "ti-sci-reset",
201*65c8a798SAndreas Dannenberg .id = UCLASS_RESET,
202*65c8a798SAndreas Dannenberg .of_match = ti_sci_reset_of_match,
203*65c8a798SAndreas Dannenberg .probe = ti_sci_reset_probe,
204*65c8a798SAndreas Dannenberg .priv_auto_alloc_size = sizeof(struct ti_sci_reset_data),
205*65c8a798SAndreas Dannenberg .ops = &ti_sci_reset_ops,
206*65c8a798SAndreas Dannenberg };
207