2 * omap-rng.c - RNG driver for TI OMAP CPU family
4 * Author: Deepak Saxena <dsaxena@plexity.net>
6 * Copyright 2005 (c) MontaVista Software, Inc.
8 * Mostly based on original driver:
10 * Copyright (C) 2005 Nokia Corporation
11 * Author: Juha Yrjölä <juha.yrjola@nokia.com>
13 * This file is licensed under the terms of the GNU General Public
14 * License version 2. This program is licensed "as is" without any
15 * warranty of any kind, whether express or implied.
18 #include <linux/module.h>
19 #include <linux/init.h>
20 #include <linux/random.h>
21 #include <linux/err.h>
22 #include <linux/platform_device.h>
23 #include <linux/hw_random.h>
24 #include <linux/delay.h>
25 #include <linux/slab.h>
26 #include <linux/pm_runtime.h>
28 #include <linux/of_device.h>
29 #include <linux/of_address.h>
30 #include <linux/interrupt.h>
31 #include <linux/clk.h>
35 #define RNG_REG_STATUS_RDY (1 << 0)
37 #define RNG_REG_INTACK_RDY_MASK (1 << 0)
38 #define RNG_REG_INTACK_SHUTDOWN_OFLO_MASK (1 << 1)
39 #define RNG_SHUTDOWN_OFLO_MASK (1 << 1)
41 #define RNG_CONTROL_STARTUP_CYCLES_SHIFT 16
42 #define RNG_CONTROL_STARTUP_CYCLES_MASK (0xffff << 16)
43 #define RNG_CONTROL_ENABLE_TRNG_SHIFT 10
44 #define RNG_CONTROL_ENABLE_TRNG_MASK (1 << 10)
46 #define RNG_CONFIG_MAX_REFIL_CYCLES_SHIFT 16
47 #define RNG_CONFIG_MAX_REFIL_CYCLES_MASK (0xffff << 16)
48 #define RNG_CONFIG_MIN_REFIL_CYCLES_SHIFT 0
49 #define RNG_CONFIG_MIN_REFIL_CYCLES_MASK (0xff << 0)
51 #define RNG_CONTROL_STARTUP_CYCLES 0xff
52 #define RNG_CONFIG_MIN_REFIL_CYCLES 0x21
53 #define RNG_CONFIG_MAX_REFIL_CYCLES 0x22
55 #define RNG_ALARMCNT_ALARM_TH_SHIFT 0x0
56 #define RNG_ALARMCNT_ALARM_TH_MASK (0xff << 0)
57 #define RNG_ALARMCNT_SHUTDOWN_TH_SHIFT 16
58 #define RNG_ALARMCNT_SHUTDOWN_TH_MASK (0x1f << 16)
59 #define RNG_ALARM_THRESHOLD 0xff
60 #define RNG_SHUTDOWN_THRESHOLD 0x4
62 #define RNG_REG_FROENABLE_MASK 0xffffff
63 #define RNG_REG_FRODETUNE_MASK 0xffffff
65 #define OMAP2_RNG_OUTPUT_SIZE 0x4
66 #define OMAP4_RNG_OUTPUT_SIZE 0x8
67 #define EIP76_RNG_OUTPUT_SIZE 0x10
70 * EIP76 RNG takes approx. 700us to produce 16 bytes of output data
71 * as per testing results. And to account for the lack of udelay()'s
72 * reliability, we keep the timeout as 1000us.
74 #define RNG_DATA_FILL_TIMEOUT 100
95 static const u16 reg_map_omap2
[] = {
96 [RNG_OUTPUT_0_REG
] = 0x0,
97 [RNG_STATUS_REG
] = 0x4,
98 [RNG_CONFIG_REG
] = 0x28,
100 [RNG_SYSCONFIG_REG
] = 0x40,
103 static const u16 reg_map_omap4
[] = {
104 [RNG_OUTPUT_0_REG
] = 0x0,
105 [RNG_OUTPUT_1_REG
] = 0x4,
106 [RNG_STATUS_REG
] = 0x8,
107 [RNG_INTMASK_REG
] = 0xc,
108 [RNG_INTACK_REG
] = 0x10,
109 [RNG_CONTROL_REG
] = 0x14,
110 [RNG_CONFIG_REG
] = 0x18,
111 [RNG_ALARMCNT_REG
] = 0x1c,
112 [RNG_FROENABLE_REG
] = 0x20,
113 [RNG_FRODETUNE_REG
] = 0x24,
114 [RNG_ALARMMASK_REG
] = 0x28,
115 [RNG_ALARMSTOP_REG
] = 0x2c,
116 [RNG_REV_REG
] = 0x1FE0,
117 [RNG_SYSCONFIG_REG
] = 0x1FE4,
120 static const u16 reg_map_eip76
[] = {
121 [RNG_OUTPUT_0_REG
] = 0x0,
122 [RNG_OUTPUT_1_REG
] = 0x4,
123 [RNG_OUTPUT_2_REG
] = 0x8,
124 [RNG_OUTPUT_3_REG
] = 0xc,
125 [RNG_STATUS_REG
] = 0x10,
126 [RNG_INTACK_REG
] = 0x10,
127 [RNG_CONTROL_REG
] = 0x14,
128 [RNG_CONFIG_REG
] = 0x18,
129 [RNG_ALARMCNT_REG
] = 0x1c,
130 [RNG_FROENABLE_REG
] = 0x20,
131 [RNG_FRODETUNE_REG
] = 0x24,
132 [RNG_ALARMMASK_REG
] = 0x28,
133 [RNG_ALARMSTOP_REG
] = 0x2c,
134 [RNG_REV_REG
] = 0x7c,
139 * struct omap_rng_pdata - RNG IP block-specific data
140 * @regs: Pointer to the register offsets structure.
141 * @data_size: No. of bytes in RNG output.
142 * @data_present: Callback to determine if data is available.
143 * @init: Callback for IP specific initialization sequence.
144 * @cleanup: Callback for IP specific cleanup sequence.
146 struct omap_rng_pdata
{
149 u32 (*data_present
)(struct omap_rng_dev
*priv
);
150 int (*init
)(struct omap_rng_dev
*priv
);
151 void (*cleanup
)(struct omap_rng_dev
*priv
);
154 struct omap_rng_dev
{
157 const struct omap_rng_pdata
*pdata
;
162 static inline u32
omap_rng_read(struct omap_rng_dev
*priv
, u16 reg
)
164 return __raw_readl(priv
->base
+ priv
->pdata
->regs
[reg
]);
167 static inline void omap_rng_write(struct omap_rng_dev
*priv
, u16 reg
,
170 __raw_writel(val
, priv
->base
+ priv
->pdata
->regs
[reg
]);
174 static int omap_rng_do_read(struct hwrng
*rng
, void *data
, size_t max
,
177 struct omap_rng_dev
*priv
;
180 priv
= (struct omap_rng_dev
*)rng
->priv
;
182 if (max
< priv
->pdata
->data_size
)
185 for (i
= 0; i
< RNG_DATA_FILL_TIMEOUT
; i
++) {
186 present
= priv
->pdata
->data_present(priv
);
187 if (present
|| !wait
)
195 memcpy_fromio(data
, priv
->base
+ priv
->pdata
->regs
[RNG_OUTPUT_0_REG
],
196 priv
->pdata
->data_size
);
198 if (priv
->pdata
->regs
[RNG_INTACK_REG
])
199 omap_rng_write(priv
, RNG_INTACK_REG
, RNG_REG_INTACK_RDY_MASK
);
201 return priv
->pdata
->data_size
;
204 static int omap_rng_init(struct hwrng
*rng
)
206 struct omap_rng_dev
*priv
;
208 priv
= (struct omap_rng_dev
*)rng
->priv
;
209 return priv
->pdata
->init(priv
);
212 static void omap_rng_cleanup(struct hwrng
*rng
)
214 struct omap_rng_dev
*priv
;
216 priv
= (struct omap_rng_dev
*)rng
->priv
;
217 priv
->pdata
->cleanup(priv
);
221 static inline u32
omap2_rng_data_present(struct omap_rng_dev
*priv
)
223 return omap_rng_read(priv
, RNG_STATUS_REG
) ? 0 : 1;
226 static int omap2_rng_init(struct omap_rng_dev
*priv
)
228 omap_rng_write(priv
, RNG_SYSCONFIG_REG
, 0x1);
232 static void omap2_rng_cleanup(struct omap_rng_dev
*priv
)
234 omap_rng_write(priv
, RNG_SYSCONFIG_REG
, 0x0);
237 static struct omap_rng_pdata omap2_rng_pdata
= {
238 .regs
= (u16
*)reg_map_omap2
,
239 .data_size
= OMAP2_RNG_OUTPUT_SIZE
,
240 .data_present
= omap2_rng_data_present
,
241 .init
= omap2_rng_init
,
242 .cleanup
= omap2_rng_cleanup
,
245 #if defined(CONFIG_OF)
246 static inline u32
omap4_rng_data_present(struct omap_rng_dev
*priv
)
248 return omap_rng_read(priv
, RNG_STATUS_REG
) & RNG_REG_STATUS_RDY
;
251 static int eip76_rng_init(struct omap_rng_dev
*priv
)
255 /* Return if RNG is already running. */
256 if (omap_rng_read(priv
, RNG_CONTROL_REG
) & RNG_CONTROL_ENABLE_TRNG_MASK
)
259 /* Number of 512 bit blocks of raw Noise Source output data that must
260 * be processed by either the Conditioning Function or the
261 * SP 800-90 DRBG ‘BC_DF’ functionality to yield a ‘full entropy’
264 val
= 0x5 << RNG_CONFIG_MIN_REFIL_CYCLES_SHIFT
;
266 /* Number of FRO samples that are XOR-ed together into one bit to be
267 * shifted into the main shift register
269 val
|= RNG_CONFIG_MAX_REFIL_CYCLES
<< RNG_CONFIG_MAX_REFIL_CYCLES_SHIFT
;
270 omap_rng_write(priv
, RNG_CONFIG_REG
, val
);
272 /* Enable all available FROs */
273 omap_rng_write(priv
, RNG_FRODETUNE_REG
, 0x0);
274 omap_rng_write(priv
, RNG_FROENABLE_REG
, RNG_REG_FROENABLE_MASK
);
277 val
= RNG_CONTROL_ENABLE_TRNG_MASK
;
278 omap_rng_write(priv
, RNG_CONTROL_REG
, val
);
283 static int omap4_rng_init(struct omap_rng_dev
*priv
)
287 /* Return if RNG is already running. */
288 if (omap_rng_read(priv
, RNG_CONTROL_REG
) & RNG_CONTROL_ENABLE_TRNG_MASK
)
291 val
= RNG_CONFIG_MIN_REFIL_CYCLES
<< RNG_CONFIG_MIN_REFIL_CYCLES_SHIFT
;
292 val
|= RNG_CONFIG_MAX_REFIL_CYCLES
<< RNG_CONFIG_MAX_REFIL_CYCLES_SHIFT
;
293 omap_rng_write(priv
, RNG_CONFIG_REG
, val
);
295 omap_rng_write(priv
, RNG_FRODETUNE_REG
, 0x0);
296 omap_rng_write(priv
, RNG_FROENABLE_REG
, RNG_REG_FROENABLE_MASK
);
297 val
= RNG_ALARM_THRESHOLD
<< RNG_ALARMCNT_ALARM_TH_SHIFT
;
298 val
|= RNG_SHUTDOWN_THRESHOLD
<< RNG_ALARMCNT_SHUTDOWN_TH_SHIFT
;
299 omap_rng_write(priv
, RNG_ALARMCNT_REG
, val
);
301 val
= RNG_CONTROL_STARTUP_CYCLES
<< RNG_CONTROL_STARTUP_CYCLES_SHIFT
;
302 val
|= RNG_CONTROL_ENABLE_TRNG_MASK
;
303 omap_rng_write(priv
, RNG_CONTROL_REG
, val
);
308 static void omap4_rng_cleanup(struct omap_rng_dev
*priv
)
312 val
= omap_rng_read(priv
, RNG_CONTROL_REG
);
313 val
&= ~RNG_CONTROL_ENABLE_TRNG_MASK
;
314 omap_rng_write(priv
, RNG_CONTROL_REG
, val
);
317 static irqreturn_t
omap4_rng_irq(int irq
, void *dev_id
)
319 struct omap_rng_dev
*priv
= dev_id
;
320 u32 fro_detune
, fro_enable
;
323 * Interrupt raised by a fro shutdown threshold, do the following:
324 * 1. Clear the alarm events.
325 * 2. De tune the FROs which are shutdown.
326 * 3. Re enable the shutdown FROs.
328 omap_rng_write(priv
, RNG_ALARMMASK_REG
, 0x0);
329 omap_rng_write(priv
, RNG_ALARMSTOP_REG
, 0x0);
331 fro_enable
= omap_rng_read(priv
, RNG_FROENABLE_REG
);
332 fro_detune
= ~fro_enable
& RNG_REG_FRODETUNE_MASK
;
333 fro_detune
= fro_detune
| omap_rng_read(priv
, RNG_FRODETUNE_REG
);
334 fro_enable
= RNG_REG_FROENABLE_MASK
;
336 omap_rng_write(priv
, RNG_FRODETUNE_REG
, fro_detune
);
337 omap_rng_write(priv
, RNG_FROENABLE_REG
, fro_enable
);
339 omap_rng_write(priv
, RNG_INTACK_REG
, RNG_REG_INTACK_SHUTDOWN_OFLO_MASK
);
344 static struct omap_rng_pdata omap4_rng_pdata
= {
345 .regs
= (u16
*)reg_map_omap4
,
346 .data_size
= OMAP4_RNG_OUTPUT_SIZE
,
347 .data_present
= omap4_rng_data_present
,
348 .init
= omap4_rng_init
,
349 .cleanup
= omap4_rng_cleanup
,
352 static struct omap_rng_pdata eip76_rng_pdata
= {
353 .regs
= (u16
*)reg_map_eip76
,
354 .data_size
= EIP76_RNG_OUTPUT_SIZE
,
355 .data_present
= omap4_rng_data_present
,
356 .init
= eip76_rng_init
,
357 .cleanup
= omap4_rng_cleanup
,
360 static const struct of_device_id omap_rng_of_match
[] = {
362 .compatible
= "ti,omap2-rng",
363 .data
= &omap2_rng_pdata
,
366 .compatible
= "ti,omap4-rng",
367 .data
= &omap4_rng_pdata
,
370 .compatible
= "inside-secure,safexcel-eip76",
371 .data
= &eip76_rng_pdata
,
375 MODULE_DEVICE_TABLE(of
, omap_rng_of_match
);
377 static int of_get_omap_rng_device_details(struct omap_rng_dev
*priv
,
378 struct platform_device
*pdev
)
380 const struct of_device_id
*match
;
381 struct device
*dev
= &pdev
->dev
;
384 match
= of_match_device(of_match_ptr(omap_rng_of_match
), dev
);
386 dev_err(dev
, "no compatible OF match\n");
389 priv
->pdata
= match
->data
;
391 if (of_device_is_compatible(dev
->of_node
, "ti,omap4-rng") ||
392 of_device_is_compatible(dev
->of_node
, "inside-secure,safexcel-eip76")) {
393 irq
= platform_get_irq(pdev
, 0);
395 dev_err(dev
, "%s: error getting IRQ resource - %d\n",
400 err
= devm_request_irq(dev
, irq
, omap4_rng_irq
,
401 IRQF_TRIGGER_NONE
, dev_name(dev
), priv
);
403 dev_err(dev
, "unable to request irq %d, err = %d\n",
409 * On OMAP4, enabling the shutdown_oflo interrupt is
410 * done in the interrupt mask register. There is no
411 * such register on EIP76, and it's enabled by the
412 * same bit in the control register
414 if (priv
->pdata
->regs
[RNG_INTMASK_REG
])
415 omap_rng_write(priv
, RNG_INTMASK_REG
,
416 RNG_SHUTDOWN_OFLO_MASK
);
418 omap_rng_write(priv
, RNG_CONTROL_REG
,
419 RNG_SHUTDOWN_OFLO_MASK
);
424 static int of_get_omap_rng_device_details(struct omap_rng_dev
*omap_rng
,
425 struct platform_device
*pdev
)
431 static int get_omap_rng_device_details(struct omap_rng_dev
*omap_rng
)
433 /* Only OMAP2/3 can be non-DT */
434 omap_rng
->pdata
= &omap2_rng_pdata
;
438 static int omap_rng_probe(struct platform_device
*pdev
)
440 struct omap_rng_dev
*priv
;
441 struct resource
*res
;
442 struct device
*dev
= &pdev
->dev
;
445 priv
= devm_kzalloc(dev
, sizeof(struct omap_rng_dev
), GFP_KERNEL
);
449 priv
->rng
.read
= omap_rng_do_read
;
450 priv
->rng
.init
= omap_rng_init
;
451 priv
->rng
.cleanup
= omap_rng_cleanup
;
452 priv
->rng
.quality
= 900;
454 priv
->rng
.priv
= (unsigned long)priv
;
455 platform_set_drvdata(pdev
, priv
);
458 res
= platform_get_resource(pdev
, IORESOURCE_MEM
, 0);
459 priv
->base
= devm_ioremap_resource(dev
, res
);
460 if (IS_ERR(priv
->base
)) {
461 ret
= PTR_ERR(priv
->base
);
465 priv
->rng
.name
= devm_kstrdup(dev
, dev_name(dev
), GFP_KERNEL
);
466 if (!priv
->rng
.name
) {
471 pm_runtime_enable(&pdev
->dev
);
472 ret
= pm_runtime_get_sync(&pdev
->dev
);
474 dev_err(&pdev
->dev
, "Failed to runtime_get device: %d\n", ret
);
475 pm_runtime_put_noidle(&pdev
->dev
);
479 priv
->clk
= devm_clk_get(&pdev
->dev
, NULL
);
480 if (IS_ERR(priv
->clk
) && PTR_ERR(priv
->clk
) == -EPROBE_DEFER
)
481 return -EPROBE_DEFER
;
482 if (!IS_ERR(priv
->clk
)) {
483 ret
= clk_prepare_enable(priv
->clk
);
486 "Unable to enable the clk: %d\n", ret
);
491 ret
= (dev
->of_node
) ? of_get_omap_rng_device_details(priv
, pdev
) :
492 get_omap_rng_device_details(priv
);
496 ret
= hwrng_register(&priv
->rng
);
500 dev_info(&pdev
->dev
, "Random Number Generator ver. %02x\n",
501 omap_rng_read(priv
, RNG_REV_REG
));
507 pm_runtime_put_sync(&pdev
->dev
);
508 pm_runtime_disable(&pdev
->dev
);
510 if (!IS_ERR(priv
->clk
))
511 clk_disable_unprepare(priv
->clk
);
513 dev_err(dev
, "initialization failed.\n");
517 static int omap_rng_remove(struct platform_device
*pdev
)
519 struct omap_rng_dev
*priv
= platform_get_drvdata(pdev
);
521 hwrng_unregister(&priv
->rng
);
523 priv
->pdata
->cleanup(priv
);
525 pm_runtime_put_sync(&pdev
->dev
);
526 pm_runtime_disable(&pdev
->dev
);
528 if (!IS_ERR(priv
->clk
))
529 clk_disable_unprepare(priv
->clk
);
534 static int __maybe_unused
omap_rng_suspend(struct device
*dev
)
536 struct omap_rng_dev
*priv
= dev_get_drvdata(dev
);
538 priv
->pdata
->cleanup(priv
);
539 pm_runtime_put_sync(dev
);
544 static int __maybe_unused
omap_rng_resume(struct device
*dev
)
546 struct omap_rng_dev
*priv
= dev_get_drvdata(dev
);
549 ret
= pm_runtime_get_sync(dev
);
551 dev_err(dev
, "Failed to runtime_get device: %d\n", ret
);
552 pm_runtime_put_noidle(dev
);
556 priv
->pdata
->init(priv
);
561 static SIMPLE_DEV_PM_OPS(omap_rng_pm
, omap_rng_suspend
, omap_rng_resume
);
563 static struct platform_driver omap_rng_driver
= {
567 .of_match_table
= of_match_ptr(omap_rng_of_match
),
569 .probe
= omap_rng_probe
,
570 .remove
= omap_rng_remove
,
573 module_platform_driver(omap_rng_driver
);
574 MODULE_ALIAS("platform:omap_rng");
575 MODULE_AUTHOR("Deepak Saxena (and others)");
576 MODULE_LICENSE("GPL");