1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (c) 2011-2014, The Linux Foundation. All rights reserved.
4 * Copyright (c) 2014,2015, Linaro Ltd.
5 *
6 * SAW power controller driver
7 */
8
9 #include <linux/kernel.h>
10 #include <linux/init.h>
11 #include <linux/io.h>
12 #include <linux/slab.h>
13 #include <linux/of.h>
14 #include <linux/of_address.h>
15 #include <linux/of_device.h>
16 #include <linux/err.h>
17 #include <linux/platform_device.h>
18 #include <linux/cpuidle.h>
19 #include <linux/cpu_pm.h>
20 #include <linux/qcom_scm.h>
21
22 #include <asm/proc-fns.h>
23 #include <asm/suspend.h>
24
25 #include "dt_idle_states.h"
26
27 #define MAX_PMIC_DATA 2
28 #define MAX_SEQ_DATA 64
29 #define SPM_CTL_INDEX 0x7f
30 #define SPM_CTL_INDEX_SHIFT 4
31 #define SPM_CTL_EN BIT(0)
32
33 enum pm_sleep_mode {
34 PM_SLEEP_MODE_STBY,
35 PM_SLEEP_MODE_RET,
36 PM_SLEEP_MODE_SPC,
37 PM_SLEEP_MODE_PC,
38 PM_SLEEP_MODE_NR,
39 };
40
41 enum spm_reg {
42 SPM_REG_CFG,
43 SPM_REG_SPM_CTL,
44 SPM_REG_DLY,
45 SPM_REG_PMIC_DLY,
46 SPM_REG_PMIC_DATA_0,
47 SPM_REG_PMIC_DATA_1,
48 SPM_REG_VCTL,
49 SPM_REG_SEQ_ENTRY,
50 SPM_REG_SPM_STS,
51 SPM_REG_PMIC_STS,
52 SPM_REG_NR,
53 };
54
55 struct spm_reg_data {
56 const u8 *reg_offset;
57 u32 spm_cfg;
58 u32 spm_dly;
59 u32 pmic_dly;
60 u32 pmic_data[MAX_PMIC_DATA];
61 u8 seq[MAX_SEQ_DATA];
62 u8 start_index[PM_SLEEP_MODE_NR];
63 };
64
65 struct spm_driver_data {
66 struct cpuidle_driver cpuidle_driver;
67 void __iomem *reg_base;
68 const struct spm_reg_data *reg_data;
69 };
70
71 static const u8 spm_reg_offset_v2_1[SPM_REG_NR] = {
72 [SPM_REG_CFG] = 0x08,
73 [SPM_REG_SPM_CTL] = 0x30,
74 [SPM_REG_DLY] = 0x34,
75 [SPM_REG_SEQ_ENTRY] = 0x80,
76 };
77
78 /* SPM register data for 8974, 8084 */
79 static const struct spm_reg_data spm_reg_8974_8084_cpu = {
80 .reg_offset = spm_reg_offset_v2_1,
81 .spm_cfg = 0x1,
82 .spm_dly = 0x3C102800,
83 .seq = { 0x03, 0x0B, 0x0F, 0x00, 0x20, 0x80, 0x10, 0xE8, 0x5B, 0x03,
84 0x3B, 0xE8, 0x5B, 0x82, 0x10, 0x0B, 0x30, 0x06, 0x26, 0x30,
85 0x0F },
86 .start_index[PM_SLEEP_MODE_STBY] = 0,
87 .start_index[PM_SLEEP_MODE_SPC] = 3,
88 };
89
90 static const u8 spm_reg_offset_v1_1[SPM_REG_NR] = {
91 [SPM_REG_CFG] = 0x08,
92 [SPM_REG_SPM_CTL] = 0x20,
93 [SPM_REG_PMIC_DLY] = 0x24,
94 [SPM_REG_PMIC_DATA_0] = 0x28,
95 [SPM_REG_PMIC_DATA_1] = 0x2C,
96 [SPM_REG_SEQ_ENTRY] = 0x80,
97 };
98
99 /* SPM register data for 8064 */
100 static const struct spm_reg_data spm_reg_8064_cpu = {
101 .reg_offset = spm_reg_offset_v1_1,
102 .spm_cfg = 0x1F,
103 .pmic_dly = 0x02020004,
104 .pmic_data[0] = 0x0084009C,
105 .pmic_data[1] = 0x00A4001C,
106 .seq = { 0x03, 0x0F, 0x00, 0x24, 0x54, 0x10, 0x09, 0x03, 0x01,
107 0x10, 0x54, 0x30, 0x0C, 0x24, 0x30, 0x0F },
108 .start_index[PM_SLEEP_MODE_STBY] = 0,
109 .start_index[PM_SLEEP_MODE_SPC] = 2,
110 };
111
spm_register_write(struct spm_driver_data * drv,enum spm_reg reg,u32 val)112 static inline void spm_register_write(struct spm_driver_data *drv,
113 enum spm_reg reg, u32 val)
114 {
115 if (drv->reg_data->reg_offset[reg])
116 writel_relaxed(val, drv->reg_base +
117 drv->reg_data->reg_offset[reg]);
118 }
119
120 /* Ensure a guaranteed write, before return */
spm_register_write_sync(struct spm_driver_data * drv,enum spm_reg reg,u32 val)121 static inline void spm_register_write_sync(struct spm_driver_data *drv,
122 enum spm_reg reg, u32 val)
123 {
124 u32 ret;
125
126 if (!drv->reg_data->reg_offset[reg])
127 return;
128
129 do {
130 writel_relaxed(val, drv->reg_base +
131 drv->reg_data->reg_offset[reg]);
132 ret = readl_relaxed(drv->reg_base +
133 drv->reg_data->reg_offset[reg]);
134 if (ret == val)
135 break;
136 cpu_relax();
137 } while (1);
138 }
139
spm_register_read(struct spm_driver_data * drv,enum spm_reg reg)140 static inline u32 spm_register_read(struct spm_driver_data *drv,
141 enum spm_reg reg)
142 {
143 return readl_relaxed(drv->reg_base + drv->reg_data->reg_offset[reg]);
144 }
145
spm_set_low_power_mode(struct spm_driver_data * drv,enum pm_sleep_mode mode)146 static void spm_set_low_power_mode(struct spm_driver_data *drv,
147 enum pm_sleep_mode mode)
148 {
149 u32 start_index;
150 u32 ctl_val;
151
152 start_index = drv->reg_data->start_index[mode];
153
154 ctl_val = spm_register_read(drv, SPM_REG_SPM_CTL);
155 ctl_val &= ~(SPM_CTL_INDEX << SPM_CTL_INDEX_SHIFT);
156 ctl_val |= start_index << SPM_CTL_INDEX_SHIFT;
157 ctl_val |= SPM_CTL_EN;
158 spm_register_write_sync(drv, SPM_REG_SPM_CTL, ctl_val);
159 }
160
qcom_pm_collapse(unsigned long int unused)161 static int qcom_pm_collapse(unsigned long int unused)
162 {
163 qcom_scm_cpu_power_down(QCOM_SCM_CPU_PWR_DOWN_L2_ON);
164
165 /*
166 * Returns here only if there was a pending interrupt and we did not
167 * power down as a result.
168 */
169 return -1;
170 }
171
qcom_cpu_spc(struct spm_driver_data * drv)172 static int qcom_cpu_spc(struct spm_driver_data *drv)
173 {
174 int ret;
175
176 spm_set_low_power_mode(drv, PM_SLEEP_MODE_SPC);
177 ret = cpu_suspend(0, qcom_pm_collapse);
178 /*
179 * ARM common code executes WFI without calling into our driver and
180 * if the SPM mode is not reset, then we may accidently power down the
181 * cpu when we intended only to gate the cpu clock.
182 * Ensure the state is set to standby before returning.
183 */
184 spm_set_low_power_mode(drv, PM_SLEEP_MODE_STBY);
185
186 return ret;
187 }
188
spm_enter_idle_state(struct cpuidle_device * dev,struct cpuidle_driver * drv,int idx)189 static int spm_enter_idle_state(struct cpuidle_device *dev,
190 struct cpuidle_driver *drv, int idx)
191 {
192 struct spm_driver_data *data = container_of(drv, struct spm_driver_data,
193 cpuidle_driver);
194
195 return CPU_PM_CPU_IDLE_ENTER_PARAM(qcom_cpu_spc, idx, data);
196 }
197
198 static struct cpuidle_driver qcom_spm_idle_driver = {
199 .name = "qcom_spm",
200 .owner = THIS_MODULE,
201 .states[0] = {
202 .enter = spm_enter_idle_state,
203 .exit_latency = 1,
204 .target_residency = 1,
205 .power_usage = UINT_MAX,
206 .name = "WFI",
207 .desc = "ARM WFI",
208 }
209 };
210
211 static const struct of_device_id qcom_idle_state_match[] = {
212 { .compatible = "qcom,idle-state-spc", .data = spm_enter_idle_state },
213 { },
214 };
215
spm_cpuidle_init(struct cpuidle_driver * drv,int cpu)216 static int spm_cpuidle_init(struct cpuidle_driver *drv, int cpu)
217 {
218 int ret;
219
220 memcpy(drv, &qcom_spm_idle_driver, sizeof(*drv));
221 drv->cpumask = (struct cpumask *)cpumask_of(cpu);
222
223 /* Parse idle states from device tree */
224 ret = dt_init_idle_driver(drv, qcom_idle_state_match, 1);
225 if (ret <= 0)
226 return ret ? : -ENODEV;
227
228 /* We have atleast one power down mode */
229 return qcom_scm_set_warm_boot_addr(cpu_resume_arm, drv->cpumask);
230 }
231
spm_get_drv(struct platform_device * pdev,int * spm_cpu)232 static struct spm_driver_data *spm_get_drv(struct platform_device *pdev,
233 int *spm_cpu)
234 {
235 struct spm_driver_data *drv = NULL;
236 struct device_node *cpu_node, *saw_node;
237 int cpu;
238 bool found = 0;
239
240 for_each_possible_cpu(cpu) {
241 cpu_node = of_cpu_device_node_get(cpu);
242 if (!cpu_node)
243 continue;
244 saw_node = of_parse_phandle(cpu_node, "qcom,saw", 0);
245 found = (saw_node == pdev->dev.of_node);
246 of_node_put(saw_node);
247 of_node_put(cpu_node);
248 if (found)
249 break;
250 }
251
252 if (found) {
253 drv = devm_kzalloc(&pdev->dev, sizeof(*drv), GFP_KERNEL);
254 if (drv)
255 *spm_cpu = cpu;
256 }
257
258 return drv;
259 }
260
261 static const struct of_device_id spm_match_table[] = {
262 { .compatible = "qcom,msm8974-saw2-v2.1-cpu",
263 .data = &spm_reg_8974_8084_cpu },
264 { .compatible = "qcom,apq8084-saw2-v2.1-cpu",
265 .data = &spm_reg_8974_8084_cpu },
266 { .compatible = "qcom,apq8064-saw2-v1.1-cpu",
267 .data = &spm_reg_8064_cpu },
268 { },
269 };
270
spm_dev_probe(struct platform_device * pdev)271 static int spm_dev_probe(struct platform_device *pdev)
272 {
273 struct spm_driver_data *drv;
274 struct resource *res;
275 const struct of_device_id *match_id;
276 void __iomem *addr;
277 int cpu, ret;
278
279 if (!qcom_scm_is_available())
280 return -EPROBE_DEFER;
281
282 drv = spm_get_drv(pdev, &cpu);
283 if (!drv)
284 return -EINVAL;
285 platform_set_drvdata(pdev, drv);
286
287 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
288 drv->reg_base = devm_ioremap_resource(&pdev->dev, res);
289 if (IS_ERR(drv->reg_base))
290 return PTR_ERR(drv->reg_base);
291
292 match_id = of_match_node(spm_match_table, pdev->dev.of_node);
293 if (!match_id)
294 return -ENODEV;
295
296 drv->reg_data = match_id->data;
297
298 ret = spm_cpuidle_init(&drv->cpuidle_driver, cpu);
299 if (ret)
300 return ret;
301
302 /* Write the SPM sequences first.. */
303 addr = drv->reg_base + drv->reg_data->reg_offset[SPM_REG_SEQ_ENTRY];
304 __iowrite32_copy(addr, drv->reg_data->seq,
305 ARRAY_SIZE(drv->reg_data->seq) / 4);
306
307 /*
308 * ..and then the control registers.
309 * On some SoC if the control registers are written first and if the
310 * CPU was held in reset, the reset signal could trigger the SPM state
311 * machine, before the sequences are completely written.
312 */
313 spm_register_write(drv, SPM_REG_CFG, drv->reg_data->spm_cfg);
314 spm_register_write(drv, SPM_REG_DLY, drv->reg_data->spm_dly);
315 spm_register_write(drv, SPM_REG_PMIC_DLY, drv->reg_data->pmic_dly);
316 spm_register_write(drv, SPM_REG_PMIC_DATA_0,
317 drv->reg_data->pmic_data[0]);
318 spm_register_write(drv, SPM_REG_PMIC_DATA_1,
319 drv->reg_data->pmic_data[1]);
320
321 /* Set up Standby as the default low power mode */
322 spm_set_low_power_mode(drv, PM_SLEEP_MODE_STBY);
323
324 return cpuidle_register(&drv->cpuidle_driver, NULL);
325 }
326
spm_dev_remove(struct platform_device * pdev)327 static int spm_dev_remove(struct platform_device *pdev)
328 {
329 struct spm_driver_data *drv = platform_get_drvdata(pdev);
330
331 cpuidle_unregister(&drv->cpuidle_driver);
332 return 0;
333 }
334
335 static struct platform_driver spm_driver = {
336 .probe = spm_dev_probe,
337 .remove = spm_dev_remove,
338 .driver = {
339 .name = "saw",
340 .of_match_table = spm_match_table,
341 },
342 };
343
344 builtin_platform_driver(spm_driver);
345