1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * The Vendor OEM extension for System Control and Power Interface (SCMI)
4 * Protocol based clock driver
5 *
6 * Copyright 2025 NXP
7 */
8
9 #include <linux/clk-provider.h>
10 #include <linux/of.h>
11 #include <linux/scmi_imx_protocol.h>
12 #include <linux/scmi_protocol.h>
13
14 #include "clk-scmi.h"
15
16 #define SCMI_CLOCK_CFG_IMX_SSC 0x80
17 #define SCMI_CLOCK_IMX_SS_PERCENTAGE_MASK GENMASK(7, 0)
18 #define SCMI_CLOCK_IMX_SS_MOD_FREQ_MASK GENMASK(23, 8)
19 #define SCMI_CLOCK_IMX_SS_ENABLE_MASK BIT(24)
20
21 /*
22 * Selection is based on SCMI vendor_id/sub_vendor_id and optional machine
23 * compatible string, without involving impl_ver. impl_ver‑specific behavior
24 * should be considered a bug and handled via SCMI Quirk framework.
25 */
26 struct scmi_clk_oem_info {
27 char *vendor_id;
28 char *sub_vendor_id;
29 char *compatible;
30 const void *data;
31 };
32
33 static int
scmi_clk_imx_set_spread_spectrum(struct clk_hw * hw,const struct clk_spread_spectrum * ss_conf)34 scmi_clk_imx_set_spread_spectrum(struct clk_hw *hw,
35 const struct clk_spread_spectrum *ss_conf)
36 {
37 struct scmi_clk *clk = to_scmi_clk(hw);
38 int ret;
39 u32 val;
40
41 /*
42 * extConfigValue[7:0] - spread percentage (%)
43 * extConfigValue[23:8] - Modulation Frequency
44 * extConfigValue[24] - Enable/Disable
45 * extConfigValue[31:25] - Reserved
46 */
47 val = FIELD_PREP(SCMI_CLOCK_IMX_SS_PERCENTAGE_MASK, ss_conf->spread_bp / 10000);
48 val |= FIELD_PREP(SCMI_CLOCK_IMX_SS_MOD_FREQ_MASK, ss_conf->modfreq_hz);
49 if (ss_conf->method != CLK_SPREAD_NO)
50 val |= SCMI_CLOCK_IMX_SS_ENABLE_MASK;
51 ret = scmi_proto_clk_ops->config_oem_set(clk->ph, clk->id,
52 SCMI_CLOCK_CFG_IMX_SSC,
53 val, false);
54 if (ret)
55 dev_warn(clk->dev,
56 "Failed to set spread spectrum(%u,%u,%u) for clock ID %d\n",
57 ss_conf->modfreq_hz, ss_conf->spread_bp, ss_conf->method,
58 clk->id);
59
60 return ret;
61 }
62
63 static int
scmi_clk_imx_query_oem_feats(const struct scmi_protocol_handle * ph,u32 id,unsigned int * feats_key)64 scmi_clk_imx_query_oem_feats(const struct scmi_protocol_handle *ph, u32 id,
65 unsigned int *feats_key)
66 {
67 int ret;
68 u32 val;
69
70 ret = scmi_proto_clk_ops->config_oem_get(ph, id,
71 SCMI_CLOCK_CFG_IMX_SSC,
72 &val, NULL, false);
73 if (!ret)
74 *feats_key |= BIT(SCMI_CLK_EXT_OEM_SSC_SUPPORTED);
75
76 return 0;
77 }
78
79 static const struct scmi_clk_oem scmi_clk_oem_imx = {
80 .query_ext_oem_feats = scmi_clk_imx_query_oem_feats,
81 .set_spread_spectrum = scmi_clk_imx_set_spread_spectrum,
82 };
83
84 static const struct scmi_clk_oem_info info[] = {
85 { SCMI_IMX_VENDOR, SCMI_IMX_SUBVENDOR, NULL, &scmi_clk_oem_imx },
86 };
87
scmi_clk_oem_init(struct scmi_device * sdev)88 int scmi_clk_oem_init(struct scmi_device *sdev)
89 {
90 const struct scmi_handle *handle = sdev->handle;
91 int i, size = ARRAY_SIZE(info);
92
93 for (i = 0; i < size; i++) {
94 if (strcmp(handle->version->vendor_id, info[i].vendor_id) ||
95 strcmp(handle->version->sub_vendor_id, info[i].sub_vendor_id))
96 continue;
97 if (info[i].compatible &&
98 !of_machine_is_compatible(info[i].compatible))
99 continue;
100
101 break;
102 }
103
104 if (i < size)
105 dev_set_drvdata(&sdev->dev, (void *)info[i].data);
106
107 return 0;
108 }
109