xref: /linux/drivers/ata/ahci_xgene.c (revision fd7d598270724cc787982ea48bbe17ad383a8b7f)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * AppliedMicro X-Gene SoC SATA Host Controller Driver
4  *
5  * Copyright (c) 2014, Applied Micro Circuits Corporation
6  * Author: Loc Ho <lho@apm.com>
7  *         Tuan Phan <tphan@apm.com>
8  *         Suman Tripathi <stripathi@apm.com>
9  *
10  * NOTE: PM support is not currently available.
11  */
12 #include <linux/acpi.h>
13 #include <linux/module.h>
14 #include <linux/platform_device.h>
15 #include <linux/ahci_platform.h>
16 #include <linux/of_address.h>
17 #include <linux/of_device.h>
18 #include <linux/of_irq.h>
19 #include <linux/phy/phy.h>
20 #include "ahci.h"
21 
22 #define DRV_NAME "xgene-ahci"
23 
24 /* Max # of disk per a controller */
25 #define MAX_AHCI_CHN_PERCTR		2
26 
27 /* MUX CSR */
28 #define SATA_ENET_CONFIG_REG		0x00000000
29 #define  CFG_SATA_ENET_SELECT_MASK	0x00000001
30 
31 /* SATA core host controller CSR */
32 #define SLVRDERRATTRIBUTES		0x00000000
33 #define SLVWRERRATTRIBUTES		0x00000004
34 #define MSTRDERRATTRIBUTES		0x00000008
35 #define MSTWRERRATTRIBUTES		0x0000000c
36 #define BUSCTLREG			0x00000014
37 #define IOFMSTRWAUX			0x00000018
38 #define INTSTATUSMASK			0x0000002c
39 #define ERRINTSTATUS			0x00000030
40 #define ERRINTSTATUSMASK		0x00000034
41 
42 /* SATA host AHCI CSR */
43 #define PORTCFG				0x000000a4
44 #define  PORTADDR_SET(dst, src) \
45 		(((dst) & ~0x0000003f) | (((u32)(src)) & 0x0000003f))
46 #define PORTPHY1CFG		0x000000a8
47 #define PORTPHY1CFG_FRCPHYRDY_SET(dst, src) \
48 		(((dst) & ~0x00100000) | (((u32)(src) << 0x14) & 0x00100000))
49 #define PORTPHY2CFG			0x000000ac
50 #define PORTPHY3CFG			0x000000b0
51 #define PORTPHY4CFG			0x000000b4
52 #define PORTPHY5CFG			0x000000b8
53 #define SCTL0				0x0000012C
54 #define PORTPHY5CFG_RTCHG_SET(dst, src) \
55 		(((dst) & ~0xfff00000) | (((u32)(src) << 0x14) & 0xfff00000))
56 #define PORTAXICFG_EN_CONTEXT_SET(dst, src) \
57 		(((dst) & ~0x01000000) | (((u32)(src) << 0x18) & 0x01000000))
58 #define PORTAXICFG			0x000000bc
59 #define PORTAXICFG_OUTTRANS_SET(dst, src) \
60 		(((dst) & ~0x00f00000) | (((u32)(src) << 0x14) & 0x00f00000))
61 #define PORTRANSCFG			0x000000c8
62 #define PORTRANSCFG_RXWM_SET(dst, src)		\
63 		(((dst) & ~0x0000007f) | (((u32)(src)) & 0x0000007f))
64 
65 /* SATA host controller AXI CSR */
66 #define INT_SLV_TMOMASK			0x00000010
67 
68 /* SATA diagnostic CSR */
69 #define CFG_MEM_RAM_SHUTDOWN		0x00000070
70 #define BLOCK_MEM_RDY			0x00000074
71 
72 /* Max retry for link down */
73 #define MAX_LINK_DOWN_RETRY 3
74 
75 enum xgene_ahci_version {
76 	XGENE_AHCI_V1 = 1,
77 	XGENE_AHCI_V2,
78 };
79 
80 struct xgene_ahci_context {
81 	struct ahci_host_priv *hpriv;
82 	struct device *dev;
83 	u8 last_cmd[MAX_AHCI_CHN_PERCTR]; /* tracking the last command issued*/
84 	u32 class[MAX_AHCI_CHN_PERCTR]; /* tracking the class of device */
85 	void __iomem *csr_core;		/* Core CSR address of IP */
86 	void __iomem *csr_diag;		/* Diag CSR address of IP */
87 	void __iomem *csr_axi;		/* AXI CSR address of IP */
88 	void __iomem *csr_mux;		/* MUX CSR address of IP */
89 };
90 
91 static int xgene_ahci_init_memram(struct xgene_ahci_context *ctx)
92 {
93 	dev_dbg(ctx->dev, "Release memory from shutdown\n");
94 	writel(0x0, ctx->csr_diag + CFG_MEM_RAM_SHUTDOWN);
95 	readl(ctx->csr_diag + CFG_MEM_RAM_SHUTDOWN); /* Force a barrier */
96 	msleep(1);	/* reset may take up to 1ms */
97 	if (readl(ctx->csr_diag + BLOCK_MEM_RDY) != 0xFFFFFFFF) {
98 		dev_err(ctx->dev, "failed to release memory from shutdown\n");
99 		return -ENODEV;
100 	}
101 	return 0;
102 }
103 
104 /**
105  * xgene_ahci_poll_reg_val- Poll a register on a specific value.
106  * @ap : ATA port of interest.
107  * @reg : Register of interest.
108  * @val : Value to be attained.
109  * @interval : waiting interval for polling.
110  * @timeout : timeout for achieving the value.
111  */
112 static int xgene_ahci_poll_reg_val(struct ata_port *ap,
113 				   void __iomem *reg, unsigned int val,
114 				   unsigned int interval, unsigned int timeout)
115 {
116 	unsigned long deadline;
117 	unsigned int tmp;
118 
119 	tmp = ioread32(reg);
120 	deadline = ata_deadline(jiffies, timeout);
121 
122 	while (tmp != val && time_before(jiffies, deadline)) {
123 		ata_msleep(ap, interval);
124 		tmp = ioread32(reg);
125 	}
126 
127 	return tmp;
128 }
129 
130 /**
131  * xgene_ahci_restart_engine - Restart the dma engine.
132  * @ap : ATA port of interest
133  *
134  * Waits for completion of multiple commands and restarts
135  * the DMA engine inside the controller.
136  */
137 static int xgene_ahci_restart_engine(struct ata_port *ap)
138 {
139 	struct ahci_host_priv *hpriv = ap->host->private_data;
140 	struct ahci_port_priv *pp = ap->private_data;
141 	void __iomem *port_mmio = ahci_port_base(ap);
142 	u32 fbs;
143 
144 	/*
145 	 * In case of PMP multiple IDENTIFY DEVICE commands can be
146 	 * issued inside PxCI. So need to poll PxCI for the
147 	 * completion of outstanding IDENTIFY DEVICE commands before
148 	 * we restart the DMA engine.
149 	 */
150 	if (xgene_ahci_poll_reg_val(ap, port_mmio +
151 				    PORT_CMD_ISSUE, 0x0, 1, 100))
152 		  return -EBUSY;
153 
154 	hpriv->stop_engine(ap);
155 	ahci_start_fis_rx(ap);
156 
157 	/*
158 	 * Enable the PxFBS.FBS_EN bit as it
159 	 * gets cleared due to stopping the engine.
160 	 */
161 	if (pp->fbs_supported) {
162 		fbs = readl(port_mmio + PORT_FBS);
163 		writel(fbs | PORT_FBS_EN, port_mmio + PORT_FBS);
164 		fbs = readl(port_mmio + PORT_FBS);
165 	}
166 
167 	hpriv->start_engine(ap);
168 
169 	return 0;
170 }
171 
172 /**
173  * xgene_ahci_qc_issue - Issue commands to the device
174  * @qc: Command to issue
175  *
176  * Due to Hardware errata for IDENTIFY DEVICE command, the controller cannot
177  * clear the BSY bit after receiving the PIO setup FIS. This results in the dma
178  * state machine goes into the CMFatalErrorUpdate state and locks up. By
179  * restarting the dma engine, it removes the controller out of lock up state.
180  *
181  * Due to H/W errata, the controller is unable to save the PMP
182  * field fetched from command header before sending the H2D FIS.
183  * When the device returns the PMP port field in the D2H FIS, there is
184  * a mismatch and results in command completion failure. The
185  * workaround is to write the pmp value to PxFBS.DEV field before issuing
186  * any command to PMP.
187  */
188 static unsigned int xgene_ahci_qc_issue(struct ata_queued_cmd *qc)
189 {
190 	struct ata_port *ap = qc->ap;
191 	struct ahci_host_priv *hpriv = ap->host->private_data;
192 	struct xgene_ahci_context *ctx = hpriv->plat_data;
193 	int rc = 0;
194 	u32 port_fbs;
195 	void __iomem *port_mmio = ahci_port_base(ap);
196 
197 	/*
198 	 * Write the pmp value to PxFBS.DEV
199 	 * for case of Port Mulitplier.
200 	 */
201 	if (ctx->class[ap->port_no] == ATA_DEV_PMP) {
202 		port_fbs = readl(port_mmio + PORT_FBS);
203 		port_fbs &= ~PORT_FBS_DEV_MASK;
204 		port_fbs |= qc->dev->link->pmp << PORT_FBS_DEV_OFFSET;
205 		writel(port_fbs, port_mmio + PORT_FBS);
206 	}
207 
208 	if (unlikely((ctx->last_cmd[ap->port_no] == ATA_CMD_ID_ATA) ||
209 	    (ctx->last_cmd[ap->port_no] == ATA_CMD_PACKET) ||
210 	    (ctx->last_cmd[ap->port_no] == ATA_CMD_SMART)))
211 		xgene_ahci_restart_engine(ap);
212 
213 	rc = ahci_qc_issue(qc);
214 
215 	/* Save the last command issued */
216 	ctx->last_cmd[ap->port_no] = qc->tf.command;
217 
218 	return rc;
219 }
220 
221 static bool xgene_ahci_is_memram_inited(struct xgene_ahci_context *ctx)
222 {
223 	void __iomem *diagcsr = ctx->csr_diag;
224 
225 	return (readl(diagcsr + CFG_MEM_RAM_SHUTDOWN) == 0 &&
226 	        readl(diagcsr + BLOCK_MEM_RDY) == 0xFFFFFFFF);
227 }
228 
229 /**
230  * xgene_ahci_read_id - Read ID data from the specified device
231  * @dev: device
232  * @tf: proposed taskfile
233  * @id: data buffer
234  *
235  * This custom read ID function is required due to the fact that the HW
236  * does not support DEVSLP.
237  */
238 static unsigned int xgene_ahci_read_id(struct ata_device *dev,
239 				       struct ata_taskfile *tf, __le16 *id)
240 {
241 	u32 err_mask;
242 
243 	err_mask = ata_do_dev_read_id(dev, tf, id);
244 	if (err_mask)
245 		return err_mask;
246 
247 	/*
248 	 * Mask reserved area. Word78 spec of Link Power Management
249 	 * bit15-8: reserved
250 	 * bit7: NCQ autosence
251 	 * bit6: Software settings preservation supported
252 	 * bit5: reserved
253 	 * bit4: In-order sata delivery supported
254 	 * bit3: DIPM requests supported
255 	 * bit2: DMA Setup FIS Auto-Activate optimization supported
256 	 * bit1: DMA Setup FIX non-Zero buffer offsets supported
257 	 * bit0: Reserved
258 	 *
259 	 * Clear reserved bit 8 (DEVSLP bit) as we don't support DEVSLP
260 	 */
261 	id[ATA_ID_FEATURE_SUPP] &= cpu_to_le16(~(1 << 8));
262 
263 	return 0;
264 }
265 
266 static void xgene_ahci_set_phy_cfg(struct xgene_ahci_context *ctx, int channel)
267 {
268 	void __iomem *mmio = ctx->hpriv->mmio;
269 	u32 val;
270 
271 	dev_dbg(ctx->dev, "port configure mmio 0x%p channel %d\n",
272 		mmio, channel);
273 	val = readl(mmio + PORTCFG);
274 	val = PORTADDR_SET(val, channel == 0 ? 2 : 3);
275 	writel(val, mmio + PORTCFG);
276 	readl(mmio + PORTCFG);  /* Force a barrier */
277 	/* Disable fix rate */
278 	writel(0x0001fffe, mmio + PORTPHY1CFG);
279 	readl(mmio + PORTPHY1CFG); /* Force a barrier */
280 	writel(0x28183219, mmio + PORTPHY2CFG);
281 	readl(mmio + PORTPHY2CFG); /* Force a barrier */
282 	writel(0x13081008, mmio + PORTPHY3CFG);
283 	readl(mmio + PORTPHY3CFG); /* Force a barrier */
284 	writel(0x00480815, mmio + PORTPHY4CFG);
285 	readl(mmio + PORTPHY4CFG); /* Force a barrier */
286 	/* Set window negotiation */
287 	val = readl(mmio + PORTPHY5CFG);
288 	val = PORTPHY5CFG_RTCHG_SET(val, 0x300);
289 	writel(val, mmio + PORTPHY5CFG);
290 	readl(mmio + PORTPHY5CFG); /* Force a barrier */
291 	val = readl(mmio + PORTAXICFG);
292 	val = PORTAXICFG_EN_CONTEXT_SET(val, 0x1); /* Enable context mgmt */
293 	val = PORTAXICFG_OUTTRANS_SET(val, 0xe); /* Set outstanding */
294 	writel(val, mmio + PORTAXICFG);
295 	readl(mmio + PORTAXICFG); /* Force a barrier */
296 	/* Set the watermark threshold of the receive FIFO */
297 	val = readl(mmio + PORTRANSCFG);
298 	val = PORTRANSCFG_RXWM_SET(val, 0x30);
299 	writel(val, mmio + PORTRANSCFG);
300 }
301 
302 /**
303  * xgene_ahci_do_hardreset - Issue the actual COMRESET
304  * @link: link to reset
305  * @deadline: deadline jiffies for the operation
306  * @online: Return value to indicate if device online
307  *
308  * Due to the limitation of the hardware PHY, a difference set of setting is
309  * required for each supported disk speed - Gen3 (6.0Gbps), Gen2 (3.0Gbps),
310  * and Gen1 (1.5Gbps). Otherwise during long IO stress test, the PHY will
311  * report disparity error and etc. In addition, during COMRESET, there can
312  * be error reported in the register PORT_SCR_ERR. For SERR_DISPARITY and
313  * SERR_10B_8B_ERR, the PHY receiver line must be reseted. Also during long
314  * reboot cycle regression, sometimes the PHY reports link down even if the
315  * device is present because of speed negotiation failure. so need to retry
316  * the COMRESET to get the link up. The following algorithm is followed to
317  * proper configure the hardware PHY during COMRESET:
318  *
319  * Alg Part 1:
320  * 1. Start the PHY at Gen3 speed (default setting)
321  * 2. Issue the COMRESET
322  * 3. If no link, go to Alg Part 3
323  * 4. If link up, determine if the negotiated speed matches the PHY
324  *    configured speed
325  * 5. If they matched, go to Alg Part 2
326  * 6. If they do not matched and first time, configure the PHY for the linked
327  *    up disk speed and repeat step 2
328  * 7. Go to Alg Part 2
329  *
330  * Alg Part 2:
331  * 1. On link up, if there are any SERR_DISPARITY and SERR_10B_8B_ERR error
332  *    reported in the register PORT_SCR_ERR, then reset the PHY receiver line
333  * 2. Go to Alg Part 4
334  *
335  * Alg Part 3:
336  * 1. Check the PORT_SCR_STAT to see whether device presence detected but PHY
337  *    communication establishment failed and maximum link down attempts are
338  *    less than Max attempts 3 then goto Alg Part 1.
339  * 2. Go to Alg Part 4.
340  *
341  * Alg Part 4:
342  * 1. Clear any pending from register PORT_SCR_ERR.
343  *
344  * NOTE: For the initial version, we will NOT support Gen1/Gen2. In addition
345  *       and until the underlying PHY supports an method to reset the receiver
346  *       line, on detection of SERR_DISPARITY or SERR_10B_8B_ERR errors,
347  *       an warning message will be printed.
348  */
349 static int xgene_ahci_do_hardreset(struct ata_link *link,
350 				   unsigned long deadline, bool *online)
351 {
352 	const unsigned int *timing = sata_ehc_deb_timing(&link->eh_context);
353 	struct ata_port *ap = link->ap;
354 	struct ahci_host_priv *hpriv = ap->host->private_data;
355 	struct xgene_ahci_context *ctx = hpriv->plat_data;
356 	struct ahci_port_priv *pp = ap->private_data;
357 	u8 *d2h_fis = pp->rx_fis + RX_FIS_D2H_REG;
358 	void __iomem *port_mmio = ahci_port_base(ap);
359 	struct ata_taskfile tf;
360 	int link_down_retry = 0;
361 	int rc;
362 	u32 val, sstatus;
363 
364 	do {
365 		/* clear D2H reception area to properly wait for D2H FIS */
366 		ata_tf_init(link->device, &tf);
367 		tf.status = ATA_BUSY;
368 		ata_tf_to_fis(&tf, 0, 0, d2h_fis);
369 		rc = sata_link_hardreset(link, timing, deadline, online,
370 				 ahci_check_ready);
371 		if (*online) {
372 			val = readl(port_mmio + PORT_SCR_ERR);
373 			if (val & (SERR_DISPARITY | SERR_10B_8B_ERR))
374 				dev_warn(ctx->dev, "link has error\n");
375 			break;
376 		}
377 
378 		sata_scr_read(link, SCR_STATUS, &sstatus);
379 	} while (link_down_retry++ < MAX_LINK_DOWN_RETRY &&
380 		 (sstatus & 0xff) == 0x1);
381 
382 	/* clear all errors if any pending */
383 	val = readl(port_mmio + PORT_SCR_ERR);
384 	writel(val, port_mmio + PORT_SCR_ERR);
385 
386 	return rc;
387 }
388 
389 static int xgene_ahci_hardreset(struct ata_link *link, unsigned int *class,
390 				unsigned long deadline)
391 {
392 	struct ata_port *ap = link->ap;
393         struct ahci_host_priv *hpriv = ap->host->private_data;
394 	void __iomem *port_mmio = ahci_port_base(ap);
395 	bool online;
396 	int rc;
397 	u32 portcmd_saved;
398 	u32 portclb_saved;
399 	u32 portclbhi_saved;
400 	u32 portrxfis_saved;
401 	u32 portrxfishi_saved;
402 
403 	/* As hardreset resets these CSR, save it to restore later */
404 	portcmd_saved = readl(port_mmio + PORT_CMD);
405 	portclb_saved = readl(port_mmio + PORT_LST_ADDR);
406 	portclbhi_saved = readl(port_mmio + PORT_LST_ADDR_HI);
407 	portrxfis_saved = readl(port_mmio + PORT_FIS_ADDR);
408 	portrxfishi_saved = readl(port_mmio + PORT_FIS_ADDR_HI);
409 
410 	hpriv->stop_engine(ap);
411 
412 	rc = xgene_ahci_do_hardreset(link, deadline, &online);
413 
414 	/* As controller hardreset clears them, restore them */
415 	writel(portcmd_saved, port_mmio + PORT_CMD);
416 	writel(portclb_saved, port_mmio + PORT_LST_ADDR);
417 	writel(portclbhi_saved, port_mmio + PORT_LST_ADDR_HI);
418 	writel(portrxfis_saved, port_mmio + PORT_FIS_ADDR);
419 	writel(portrxfishi_saved, port_mmio + PORT_FIS_ADDR_HI);
420 
421 	hpriv->start_engine(ap);
422 
423 	if (online)
424 		*class = ahci_dev_classify(ap);
425 
426 	return rc;
427 }
428 
429 static void xgene_ahci_host_stop(struct ata_host *host)
430 {
431 	struct ahci_host_priv *hpriv = host->private_data;
432 
433 	ahci_platform_disable_resources(hpriv);
434 }
435 
436 /**
437  * xgene_ahci_pmp_softreset - Issue the softreset to the drives connected
438  *                            to Port Multiplier.
439  * @link: link to reset
440  * @class: Return value to indicate class of device
441  * @deadline: deadline jiffies for the operation
442  *
443  * Due to H/W errata, the controller is unable to save the PMP
444  * field fetched from command header before sending the H2D FIS.
445  * When the device returns the PMP port field in the D2H FIS, there is
446  * a mismatch and results in command completion failure. The workaround
447  * is to write the pmp value to PxFBS.DEV field before issuing any command
448  * to PMP.
449  */
450 static int xgene_ahci_pmp_softreset(struct ata_link *link, unsigned int *class,
451 			  unsigned long deadline)
452 {
453 	int pmp = sata_srst_pmp(link);
454 	struct ata_port *ap = link->ap;
455 	u32 rc;
456 	void __iomem *port_mmio = ahci_port_base(ap);
457 	u32 port_fbs;
458 
459 	/*
460 	 * Set PxFBS.DEV field with pmp
461 	 * value.
462 	 */
463 	port_fbs = readl(port_mmio + PORT_FBS);
464 	port_fbs &= ~PORT_FBS_DEV_MASK;
465 	port_fbs |= pmp << PORT_FBS_DEV_OFFSET;
466 	writel(port_fbs, port_mmio + PORT_FBS);
467 
468 	rc = ahci_do_softreset(link, class, pmp, deadline, ahci_check_ready);
469 
470 	return rc;
471 }
472 
473 /**
474  * xgene_ahci_softreset - Issue the softreset to the drive.
475  * @link: link to reset
476  * @class: Return value to indicate class of device
477  * @deadline: deadline jiffies for the operation
478  *
479  * Due to H/W errata, the controller is unable to save the PMP
480  * field fetched from command header before sending the H2D FIS.
481  * When the device returns the PMP port field in the D2H FIS, there is
482  * a mismatch and results in command completion failure. The workaround
483  * is to write the pmp value to PxFBS.DEV field before issuing any command
484  * to PMP. Here is the algorithm to detect PMP :
485  *
486  * 1. Save the PxFBS value
487  * 2. Program PxFBS.DEV with pmp value send by framework. Framework sends
488  *    0xF for both PMP/NON-PMP initially
489  * 3. Issue softreset
490  * 4. If signature class is PMP goto 6
491  * 5. restore the original PxFBS and goto 3
492  * 6. return
493  */
494 static int xgene_ahci_softreset(struct ata_link *link, unsigned int *class,
495 			  unsigned long deadline)
496 {
497 	int pmp = sata_srst_pmp(link);
498 	struct ata_port *ap = link->ap;
499 	struct ahci_host_priv *hpriv = ap->host->private_data;
500 	struct xgene_ahci_context *ctx = hpriv->plat_data;
501 	void __iomem *port_mmio = ahci_port_base(ap);
502 	u32 port_fbs;
503 	u32 port_fbs_save;
504 	u32 retry = 1;
505 	u32 rc;
506 
507 	port_fbs_save = readl(port_mmio + PORT_FBS);
508 
509 	/*
510 	 * Set PxFBS.DEV field with pmp
511 	 * value.
512 	 */
513 	port_fbs = readl(port_mmio + PORT_FBS);
514 	port_fbs &= ~PORT_FBS_DEV_MASK;
515 	port_fbs |= pmp << PORT_FBS_DEV_OFFSET;
516 	writel(port_fbs, port_mmio + PORT_FBS);
517 
518 softreset_retry:
519 	rc = ahci_do_softreset(link, class, pmp,
520 			       deadline, ahci_check_ready);
521 
522 	ctx->class[ap->port_no] = *class;
523 	if (*class != ATA_DEV_PMP) {
524 		/*
525 		 * Retry for normal drives without
526 		 * setting PxFBS.DEV field with pmp value.
527 		 */
528 		if (retry--) {
529 			writel(port_fbs_save, port_mmio + PORT_FBS);
530 			goto softreset_retry;
531 		}
532 	}
533 
534 	return rc;
535 }
536 
537 /**
538  * xgene_ahci_handle_broken_edge_irq - Handle the broken irq.
539  * @host: Host that recieved the irq
540  * @irq_masked: HOST_IRQ_STAT value
541  *
542  * For hardware with broken edge trigger latch
543  * the HOST_IRQ_STAT register misses the edge interrupt
544  * when clearing of HOST_IRQ_STAT register and hardware
545  * reporting the PORT_IRQ_STAT register at the
546  * same clock cycle.
547  * As such, the algorithm below outlines the workaround.
548  *
549  * 1. Read HOST_IRQ_STAT register and save the state.
550  * 2. Clear the HOST_IRQ_STAT register.
551  * 3. Read back the HOST_IRQ_STAT register.
552  * 4. If HOST_IRQ_STAT register equals to zero, then
553  *    traverse the rest of port's PORT_IRQ_STAT register
554  *    to check if an interrupt is triggered at that point else
555  *    go to step 6.
556  * 5. If PORT_IRQ_STAT register of rest ports is not equal to zero
557  *    then update the state of HOST_IRQ_STAT saved in step 1.
558  * 6. Handle port interrupts.
559  * 7. Exit
560  */
561 static int xgene_ahci_handle_broken_edge_irq(struct ata_host *host,
562 					     u32 irq_masked)
563 {
564 	struct ahci_host_priv *hpriv = host->private_data;
565 	void __iomem *port_mmio;
566 	int i;
567 
568 	if (!readl(hpriv->mmio + HOST_IRQ_STAT)) {
569 		for (i = 0; i < host->n_ports; i++) {
570 			if (irq_masked & (1 << i))
571 				continue;
572 
573 			port_mmio = ahci_port_base(host->ports[i]);
574 			if (readl(port_mmio + PORT_IRQ_STAT))
575 				irq_masked |= (1 << i);
576 		}
577 	}
578 
579 	return ahci_handle_port_intr(host, irq_masked);
580 }
581 
582 static irqreturn_t xgene_ahci_irq_intr(int irq, void *dev_instance)
583 {
584 	struct ata_host *host = dev_instance;
585 	struct ahci_host_priv *hpriv;
586 	unsigned int rc = 0;
587 	void __iomem *mmio;
588 	u32 irq_stat, irq_masked;
589 
590 	hpriv = host->private_data;
591 	mmio = hpriv->mmio;
592 
593 	/* sigh.  0xffffffff is a valid return from h/w */
594 	irq_stat = readl(mmio + HOST_IRQ_STAT);
595 	if (!irq_stat)
596 		return IRQ_NONE;
597 
598 	irq_masked = irq_stat & hpriv->port_map;
599 
600 	spin_lock(&host->lock);
601 
602 	/*
603 	 * HOST_IRQ_STAT behaves as edge triggered latch meaning that
604 	 * it should be cleared before all the port events are cleared.
605 	 */
606 	writel(irq_stat, mmio + HOST_IRQ_STAT);
607 
608 	rc = xgene_ahci_handle_broken_edge_irq(host, irq_masked);
609 
610 	spin_unlock(&host->lock);
611 
612 	return IRQ_RETVAL(rc);
613 }
614 
615 static struct ata_port_operations xgene_ahci_v1_ops = {
616 	.inherits = &ahci_ops,
617 	.host_stop = xgene_ahci_host_stop,
618 	.hardreset = xgene_ahci_hardreset,
619 	.read_id = xgene_ahci_read_id,
620 	.qc_issue = xgene_ahci_qc_issue,
621 	.softreset = xgene_ahci_softreset,
622 	.pmp_softreset = xgene_ahci_pmp_softreset
623 };
624 
625 static const struct ata_port_info xgene_ahci_v1_port_info = {
626 	.flags = AHCI_FLAG_COMMON | ATA_FLAG_PMP,
627 	.pio_mask = ATA_PIO4,
628 	.udma_mask = ATA_UDMA6,
629 	.port_ops = &xgene_ahci_v1_ops,
630 };
631 
632 static struct ata_port_operations xgene_ahci_v2_ops = {
633 	.inherits = &ahci_ops,
634 	.host_stop = xgene_ahci_host_stop,
635 	.hardreset = xgene_ahci_hardreset,
636 	.read_id = xgene_ahci_read_id,
637 };
638 
639 static const struct ata_port_info xgene_ahci_v2_port_info = {
640 	.flags = AHCI_FLAG_COMMON | ATA_FLAG_PMP,
641 	.pio_mask = ATA_PIO4,
642 	.udma_mask = ATA_UDMA6,
643 	.port_ops = &xgene_ahci_v2_ops,
644 };
645 
646 static int xgene_ahci_hw_init(struct ahci_host_priv *hpriv)
647 {
648 	struct xgene_ahci_context *ctx = hpriv->plat_data;
649 	int i;
650 	int rc;
651 	u32 val;
652 
653 	/* Remove IP RAM out of shutdown */
654 	rc = xgene_ahci_init_memram(ctx);
655 	if (rc)
656 		return rc;
657 
658 	for (i = 0; i < MAX_AHCI_CHN_PERCTR; i++)
659 		xgene_ahci_set_phy_cfg(ctx, i);
660 
661 	/* AXI disable Mask */
662 	writel(0xffffffff, hpriv->mmio + HOST_IRQ_STAT);
663 	readl(hpriv->mmio + HOST_IRQ_STAT); /* Force a barrier */
664 	writel(0, ctx->csr_core + INTSTATUSMASK);
665 	val = readl(ctx->csr_core + INTSTATUSMASK); /* Force a barrier */
666 	dev_dbg(ctx->dev, "top level interrupt mask 0x%X value 0x%08X\n",
667 		INTSTATUSMASK, val);
668 
669 	writel(0x0, ctx->csr_core + ERRINTSTATUSMASK);
670 	readl(ctx->csr_core + ERRINTSTATUSMASK); /* Force a barrier */
671 	writel(0x0, ctx->csr_axi + INT_SLV_TMOMASK);
672 	readl(ctx->csr_axi + INT_SLV_TMOMASK);
673 
674 	/* Enable AXI Interrupt */
675 	writel(0xffffffff, ctx->csr_core + SLVRDERRATTRIBUTES);
676 	writel(0xffffffff, ctx->csr_core + SLVWRERRATTRIBUTES);
677 	writel(0xffffffff, ctx->csr_core + MSTRDERRATTRIBUTES);
678 	writel(0xffffffff, ctx->csr_core + MSTWRERRATTRIBUTES);
679 
680 	/* Enable coherency */
681 	val = readl(ctx->csr_core + BUSCTLREG);
682 	val &= ~0x00000002;     /* Enable write coherency */
683 	val &= ~0x00000001;     /* Enable read coherency */
684 	writel(val, ctx->csr_core + BUSCTLREG);
685 
686 	val = readl(ctx->csr_core + IOFMSTRWAUX);
687 	val |= (1 << 3);        /* Enable read coherency */
688 	val |= (1 << 9);        /* Enable write coherency */
689 	writel(val, ctx->csr_core + IOFMSTRWAUX);
690 	val = readl(ctx->csr_core + IOFMSTRWAUX);
691 	dev_dbg(ctx->dev, "coherency 0x%X value 0x%08X\n",
692 		IOFMSTRWAUX, val);
693 
694 	return rc;
695 }
696 
697 static int xgene_ahci_mux_select(struct xgene_ahci_context *ctx)
698 {
699 	u32 val;
700 
701 	/* Check for optional MUX resource */
702 	if (!ctx->csr_mux)
703 		return 0;
704 
705 	val = readl(ctx->csr_mux + SATA_ENET_CONFIG_REG);
706 	val &= ~CFG_SATA_ENET_SELECT_MASK;
707 	writel(val, ctx->csr_mux + SATA_ENET_CONFIG_REG);
708 	val = readl(ctx->csr_mux + SATA_ENET_CONFIG_REG);
709 	return val & CFG_SATA_ENET_SELECT_MASK ? -1 : 0;
710 }
711 
712 static const struct scsi_host_template ahci_platform_sht = {
713 	AHCI_SHT(DRV_NAME),
714 };
715 
716 #ifdef CONFIG_ACPI
717 static const struct acpi_device_id xgene_ahci_acpi_match[] = {
718 	{ "APMC0D0D", XGENE_AHCI_V1},
719 	{ "APMC0D32", XGENE_AHCI_V2},
720 	{},
721 };
722 MODULE_DEVICE_TABLE(acpi, xgene_ahci_acpi_match);
723 #endif
724 
725 static const struct of_device_id xgene_ahci_of_match[] = {
726 	{.compatible = "apm,xgene-ahci", .data = (void *) XGENE_AHCI_V1},
727 	{.compatible = "apm,xgene-ahci-v2", .data = (void *) XGENE_AHCI_V2},
728 	{ /* sentinel */ }
729 };
730 MODULE_DEVICE_TABLE(of, xgene_ahci_of_match);
731 
732 static int xgene_ahci_probe(struct platform_device *pdev)
733 {
734 	struct device *dev = &pdev->dev;
735 	struct ahci_host_priv *hpriv;
736 	struct xgene_ahci_context *ctx;
737 	struct resource *res;
738 	const struct of_device_id *of_devid;
739 	enum xgene_ahci_version version = XGENE_AHCI_V1;
740 	const struct ata_port_info *ppi[] = { &xgene_ahci_v1_port_info,
741 					      &xgene_ahci_v2_port_info };
742 	int rc;
743 
744 	hpriv = ahci_platform_get_resources(pdev, 0);
745 	if (IS_ERR(hpriv))
746 		return PTR_ERR(hpriv);
747 
748 	ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
749 	if (!ctx)
750 		return -ENOMEM;
751 
752 	hpriv->plat_data = ctx;
753 	ctx->hpriv = hpriv;
754 	ctx->dev = dev;
755 
756 	/* Retrieve the IP core resource */
757 	ctx->csr_core = devm_platform_ioremap_resource(pdev, 1);
758 	if (IS_ERR(ctx->csr_core))
759 		return PTR_ERR(ctx->csr_core);
760 
761 	/* Retrieve the IP diagnostic resource */
762 	ctx->csr_diag = devm_platform_ioremap_resource(pdev, 2);
763 	if (IS_ERR(ctx->csr_diag))
764 		return PTR_ERR(ctx->csr_diag);
765 
766 	/* Retrieve the IP AXI resource */
767 	ctx->csr_axi = devm_platform_ioremap_resource(pdev, 3);
768 	if (IS_ERR(ctx->csr_axi))
769 		return PTR_ERR(ctx->csr_axi);
770 
771 	/* Retrieve the optional IP mux resource */
772 	res = platform_get_resource(pdev, IORESOURCE_MEM, 4);
773 	if (res) {
774 		void __iomem *csr = devm_ioremap_resource(dev, res);
775 		if (IS_ERR(csr))
776 			return PTR_ERR(csr);
777 
778 		ctx->csr_mux = csr;
779 	}
780 
781 	of_devid = of_match_device(xgene_ahci_of_match, dev);
782 	if (of_devid) {
783 		if (of_devid->data)
784 			version = (unsigned long) of_devid->data;
785 	}
786 #ifdef CONFIG_ACPI
787 	else {
788 		const struct acpi_device_id *acpi_id;
789 		struct acpi_device_info *info;
790 		acpi_status status;
791 
792 		acpi_id = acpi_match_device(xgene_ahci_acpi_match, &pdev->dev);
793 		if (!acpi_id) {
794 			dev_warn(&pdev->dev, "No node entry in ACPI table. Assume version1\n");
795 			version = XGENE_AHCI_V1;
796 		} else if (acpi_id->driver_data) {
797 			version = (enum xgene_ahci_version) acpi_id->driver_data;
798 			status = acpi_get_object_info(ACPI_HANDLE(&pdev->dev), &info);
799 			if (ACPI_FAILURE(status)) {
800 				dev_warn(&pdev->dev, "%s: Error reading device info. Assume version1\n",
801 					__func__);
802 				version = XGENE_AHCI_V1;
803 			} else {
804 				if (info->valid & ACPI_VALID_CID)
805 					version = XGENE_AHCI_V2;
806 				kfree(info);
807 			}
808 		}
809 	}
810 #endif
811 
812 	dev_dbg(dev, "VAddr 0x%p Mmio VAddr 0x%p\n", ctx->csr_core,
813 		hpriv->mmio);
814 
815 	/* Select ATA */
816 	if ((rc = xgene_ahci_mux_select(ctx))) {
817 		dev_err(dev, "SATA mux selection failed error %d\n", rc);
818 		return -ENODEV;
819 	}
820 
821 	if (xgene_ahci_is_memram_inited(ctx)) {
822 		dev_info(dev, "skip clock and PHY initialization\n");
823 		goto skip_clk_phy;
824 	}
825 
826 	/* Due to errata, HW requires full toggle transition */
827 	rc = ahci_platform_enable_clks(hpriv);
828 	if (rc)
829 		goto disable_resources;
830 	ahci_platform_disable_clks(hpriv);
831 
832 	rc = ahci_platform_enable_resources(hpriv);
833 	if (rc)
834 		goto disable_resources;
835 
836 	/* Configure the host controller */
837 	xgene_ahci_hw_init(hpriv);
838 skip_clk_phy:
839 
840 	switch (version) {
841 	case XGENE_AHCI_V1:
842 		hpriv->flags = AHCI_HFLAG_NO_NCQ;
843 		break;
844 	case XGENE_AHCI_V2:
845 		hpriv->flags |= AHCI_HFLAG_YES_FBS;
846 		hpriv->irq_handler = xgene_ahci_irq_intr;
847 		break;
848 	default:
849 		break;
850 	}
851 
852 	rc = ahci_platform_init_host(pdev, hpriv, ppi[version - 1],
853 				     &ahci_platform_sht);
854 	if (rc)
855 		goto disable_resources;
856 
857 	dev_dbg(dev, "X-Gene SATA host controller initialized\n");
858 	return 0;
859 
860 disable_resources:
861 	ahci_platform_disable_resources(hpriv);
862 	return rc;
863 }
864 
865 static struct platform_driver xgene_ahci_driver = {
866 	.probe = xgene_ahci_probe,
867 	.remove_new = ata_platform_remove_one,
868 	.driver = {
869 		.name = DRV_NAME,
870 		.of_match_table = xgene_ahci_of_match,
871 		.acpi_match_table = ACPI_PTR(xgene_ahci_acpi_match),
872 	},
873 };
874 
875 module_platform_driver(xgene_ahci_driver);
876 
877 MODULE_DESCRIPTION("APM X-Gene AHCI SATA driver");
878 MODULE_AUTHOR("Loc Ho <lho@apm.com>");
879 MODULE_LICENSE("GPL");
880 MODULE_VERSION("0.4");
881