forked from ~ljy/RK356X_SDK_RELEASE
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hc
2024-02-20 ea08eeccae9297f7aabd2ef7f0c2517ac4549acc 
 kernel/drivers/clocksource/sh_cmt.c
....@@ -13,6 +13,7 @@
1313 #include <linux/init.h>
1414 #include <linux/interrupt.h>
1515 #include <linux/io.h>
16
+#include <linux/iopoll.h>
1617 #include <linux/ioport.h>
1718 #include <linux/irq.h>
1819 #include <linux/module.h>
....@@ -116,6 +117,7 @@
116117 	void __iomem *mapbase;
117118 	struct clk *clk;
118119 	unsigned long rate;
120
+	unsigned int reg_delay;
119121 
120122 	raw_spinlock_t lock; /* Protect the shared start/stop register */
121123 
....@@ -235,6 +237,8 @@
235237 #define CMCNT 1 /* channel register */
236238 #define CMCOR 2 /* channel register */
237239 
240
+#define CMCLKE	0x1000	/* CLK Enable Register (R-Car Gen2) */
241
+
238242 static inline u32 sh_cmt_read_cmstr(struct sh_cmt_channel *ch)
239243 {
240244 	if (ch->iostart)
....@@ -245,10 +249,17 @@
245249 
246250 static inline void sh_cmt_write_cmstr(struct sh_cmt_channel *ch, u32 value)
247251 {
248
-	if (ch->iostart)
249
-		ch->cmt->info->write_control(ch->iostart, 0, value);
250
-	else
251
-		ch->cmt->info->write_control(ch->cmt->mapbase, 0, value);
252
+	u32 old_value = sh_cmt_read_cmstr(ch);
253
+
254
+	if (value != old_value) {
255
+		if (ch->iostart) {
256
+			ch->cmt->info->write_control(ch->iostart, 0, value);
257
+			udelay(ch->cmt->reg_delay);
258
+		} else {
259
+			ch->cmt->info->write_control(ch->cmt->mapbase, 0, value);
260
+			udelay(ch->cmt->reg_delay);
261
+		}
262
+	}
252263 }
253264 
254265 static inline u32 sh_cmt_read_cmcsr(struct sh_cmt_channel *ch)
....@@ -258,7 +269,12 @@
258269 
259270 static inline void sh_cmt_write_cmcsr(struct sh_cmt_channel *ch, u32 value)
260271 {
261
-	ch->cmt->info->write_control(ch->ioctrl, CMCSR, value);
272
+	u32 old_value = sh_cmt_read_cmcsr(ch);
273
+
274
+	if (value != old_value) {
275
+		ch->cmt->info->write_control(ch->ioctrl, CMCSR, value);
276
+		udelay(ch->cmt->reg_delay);
277
+	}
262278 }
263279 
264280 static inline u32 sh_cmt_read_cmcnt(struct sh_cmt_channel *ch)
....@@ -266,14 +282,33 @@
266282 	return ch->cmt->info->read_count(ch->ioctrl, CMCNT);
267283 }
268284 
269
-static inline void sh_cmt_write_cmcnt(struct sh_cmt_channel *ch, u32 value)
285
+static inline int sh_cmt_write_cmcnt(struct sh_cmt_channel *ch, u32 value)
270286 {
287
+	/* Tests showed that we need to wait 3 clocks here */
288
+	unsigned int cmcnt_delay = DIV_ROUND_UP(3 * ch->cmt->reg_delay, 2);
289
+	u32 reg;
290
+
291
+	if (ch->cmt->info->model > SH_CMT_16BIT) {
292
+		int ret = read_poll_timeout_atomic(sh_cmt_read_cmcsr, reg,
293
+						   !(reg & SH_CMT32_CMCSR_WRFLG),
294
+						   1, cmcnt_delay, false, ch);
295
+		if (ret < 0)
296
+			return ret;
297
+	}
298
+
271299 	ch->cmt->info->write_count(ch->ioctrl, CMCNT, value);
300
+	udelay(cmcnt_delay);
301
+	return 0;
272302 }
273303 
274304 static inline void sh_cmt_write_cmcor(struct sh_cmt_channel *ch, u32 value)
275305 {
276
-	ch->cmt->info->write_count(ch->ioctrl, CMCOR, value);
306
+	u32 old_value = ch->cmt->info->read_count(ch->ioctrl, CMCOR);
307
+
308
+	if (value != old_value) {
309
+		ch->cmt->info->write_count(ch->ioctrl, CMCOR, value);
310
+		udelay(ch->cmt->reg_delay);
311
+	}
277312 }
278313 
279314 static u32 sh_cmt_get_counter(struct sh_cmt_channel *ch, u32 *has_wrapped)
....@@ -317,7 +352,7 @@
317352 
318353 static int sh_cmt_enable(struct sh_cmt_channel *ch)
319354 {
320
-	int k, ret;
355
+	int ret;
321356 
322357 	pm_runtime_get_sync(&ch->cmt->pdev->dev);
323358 	dev_pm_syscore_device(&ch->cmt->pdev->dev, true);
....@@ -345,26 +380,9 @@
345380 	}
346381 
347382 	sh_cmt_write_cmcor(ch, 0xffffffff);
348
-	sh_cmt_write_cmcnt(ch, 0);
383
+	ret = sh_cmt_write_cmcnt(ch, 0);
349384 
350
-	/*
351
-	 * According to the sh73a0 user's manual, as CMCNT can be operated
352
-	 * only by the RCLK (Pseudo 32 kHz), there's one restriction on
353
-	 * modifying CMCNT register; two RCLK cycles are necessary before
354
-	 * this register is either read or any modification of the value
355
-	 * it holds is reflected in the LSI's actual operation.
356
-	 *
357
-	 * While at it, we're supposed to clear out the CMCNT as of this
358
-	 * moment, so make sure it's processed properly here.  This will
359
-	 * take RCLKx2 at maximum.
360
-	 */
361
-	for (k = 0; k < 100; k++) {
362
-		if (!sh_cmt_read_cmcnt(ch))
363
-			break;
364
-		udelay(1);
365
-	}
366
-
367
-	if (sh_cmt_read_cmcnt(ch)) {
385
+	if (ret || sh_cmt_read_cmcnt(ch)) {
368386 		dev_err(&ch->cmt->pdev->dev, "ch%u: cannot clear CMCNT\n",
369387 			ch->index);
370388 		ret = -ETIMEDOUT;
....@@ -849,6 +867,7 @@
849867 				unsigned int hwidx, bool clockevent,
850868 				bool clocksource, struct sh_cmt_device *cmt)
851869 {
870
+	u32 value;
852871 	int ret;
853872 
854873 	/* Skip unused channels. */
....@@ -878,6 +897,11 @@
878897 		ch->iostart = cmt->mapbase + ch->hwidx * 0x100;
879898 		ch->ioctrl = ch->iostart + 0x10;
880899 		ch->timer_bit = 0;
900
+
901
+		/* Enable the clock supply to the channel */
902
+		value = ioread32(cmt->mapbase + CMCLKE);
903
+		value |= BIT(hwidx);
904
+		iowrite32(value, cmt->mapbase + CMCLKE);
881905 		break;
882906 	}
883907 
....@@ -968,8 +992,8 @@
968992 
969993 static int sh_cmt_setup(struct sh_cmt_device *cmt, struct platform_device *pdev)
970994 {
971
-	unsigned int mask;
972
-	unsigned int i;
995
+	unsigned int mask, i;
996
+	unsigned long rate;
973997 	int ret;
974998 
975999 	cmt->pdev = pdev;
....@@ -1005,17 +1029,21 @@
10051029 	if (ret < 0)
10061030 		goto err_clk_unprepare;
10071031 
1008
-	if (cmt->info->width == 16)
1009
-		cmt->rate = clk_get_rate(cmt->clk) / 512;
1010
-	else
1011
-		cmt->rate = clk_get_rate(cmt->clk) / 8;
1032
+	rate = clk_get_rate(cmt->clk);
1033
+	if (!rate) {
1034
+		ret = -EINVAL;
1035
+		goto err_clk_disable;
1036
+	}
10121037 
1013
-	clk_disable(cmt->clk);
1038
+	/* We shall wait 2 input clks after register writes */
1039
+	if (cmt->info->model >= SH_CMT_48BIT)
1040
+		cmt->reg_delay = DIV_ROUND_UP(2UL * USEC_PER_SEC, rate);
1041
+	cmt->rate = rate / (cmt->info->width == 16 ? 512 : 8);
10141042 
10151043 	/* Map the memory resource(s). */
10161044 	ret = sh_cmt_map_memory(cmt);
10171045 	if (ret < 0)
1018
-		goto err_clk_unprepare;
1046
+		goto err_clk_disable;
10191047 
10201048 	/* Allocate and setup the channels. */
10211049 	cmt->num_channels = hweight8(cmt->hw_channels);
....@@ -1043,6 +1071,8 @@
10431071 		mask &= ~(1 << hwidx);
10441072 	}
10451073 
1074
+	clk_disable(cmt->clk);
1075
+
10461076 	platform_set_drvdata(pdev, cmt);
10471077 
10481078 	return 0;
....@@ -1050,6 +1080,8 @@
10501080 err_unmap:
10511081 	kfree(cmt->channels);
10521082 	iounmap(cmt->mapbase);
1083
+err_clk_disable:
1084
+	clk_disable(cmt->clk);
10531085 err_clk_unprepare:
10541086 	clk_unprepare(cmt->clk);
10551087 err_clk_put: