xref: /openbmc/linux/drivers/ata/ahci_mvebu.c (revision 0c874100)
1 /*
2  * AHCI glue platform driver for Marvell EBU SOCs
3  *
4  * Copyright (C) 2014 Marvell
5  *
6  * Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
7  * Marcin Wojtas <mw@semihalf.com>
8  *
9  * This file is licensed under the terms of the GNU General Public
10  * License version 2.  This program is licensed "as is" without any
11  * warranty of any kind, whether express or implied.
12  */
13 
14 #include <linux/ahci_platform.h>
15 #include <linux/kernel.h>
16 #include <linux/mbus.h>
17 #include <linux/module.h>
18 #include <linux/of_device.h>
19 #include <linux/platform_device.h>
20 #include "ahci.h"
21 
22 #define DRV_NAME "ahci-mvebu"
23 
24 #define AHCI_VENDOR_SPECIFIC_0_ADDR  0xa0
25 #define AHCI_VENDOR_SPECIFIC_0_DATA  0xa4
26 
27 #define AHCI_WINDOW_CTRL(win)	(0x60 + ((win) << 4))
28 #define AHCI_WINDOW_BASE(win)	(0x64 + ((win) << 4))
29 #define AHCI_WINDOW_SIZE(win)	(0x68 + ((win) << 4))
30 
31 static void ahci_mvebu_mbus_config(struct ahci_host_priv *hpriv,
32 				   const struct mbus_dram_target_info *dram)
33 {
34 	int i;
35 
36 	for (i = 0; i < 4; i++) {
37 		writel(0, hpriv->mmio + AHCI_WINDOW_CTRL(i));
38 		writel(0, hpriv->mmio + AHCI_WINDOW_BASE(i));
39 		writel(0, hpriv->mmio + AHCI_WINDOW_SIZE(i));
40 	}
41 
42 	for (i = 0; i < dram->num_cs; i++) {
43 		const struct mbus_dram_window *cs = dram->cs + i;
44 
45 		writel((cs->mbus_attr << 8) |
46 		       (dram->mbus_dram_target_id << 4) | 1,
47 		       hpriv->mmio + AHCI_WINDOW_CTRL(i));
48 		writel(cs->base >> 16, hpriv->mmio + AHCI_WINDOW_BASE(i));
49 		writel(((cs->size - 1) & 0xffff0000),
50 		       hpriv->mmio + AHCI_WINDOW_SIZE(i));
51 	}
52 }
53 
54 static void ahci_mvebu_regret_option(struct ahci_host_priv *hpriv)
55 {
56 	/*
57 	 * Enable the regret bit to allow the SATA unit to regret a
58 	 * request that didn't receive an acknowlegde and avoid a
59 	 * deadlock
60 	 */
61 	writel(0x4, hpriv->mmio + AHCI_VENDOR_SPECIFIC_0_ADDR);
62 	writel(0x80, hpriv->mmio + AHCI_VENDOR_SPECIFIC_0_DATA);
63 }
64 
65 /**
66  * ahci_mvebu_stop_engine
67  *
68  * @ap:	Target ata port
69  *
70  * Errata Ref#226 - SATA Disk HOT swap issue when connected through
71  * Port Multiplier in FIS-based Switching mode.
72  *
73  * To avoid the issue, according to design, the bits[11:8, 0] of
74  * register PxFBS are cleared when Port Command and Status (0x18) bit[0]
75  * changes its value from 1 to 0, i.e. falling edge of Port
76  * Command and Status bit[0] sends PULSE that resets PxFBS
77  * bits[11:8; 0].
78  *
79  * This function is used to override function of "ahci_stop_engine"
80  * from libahci.c by adding the mvebu work around(WA) to save PxFBS
81  * value before the PxCMD ST write of 0, then restore PxFBS value.
82  *
83  * Return: 0 on success; Error code otherwise.
84  */
85 static int ahci_mvebu_stop_engine(struct ata_port *ap)
86 {
87 	void __iomem *port_mmio = ahci_port_base(ap);
88 	u32 tmp, port_fbs;
89 
90 	tmp = readl(port_mmio + PORT_CMD);
91 
92 	/* check if the HBA is idle */
93 	if ((tmp & (PORT_CMD_START | PORT_CMD_LIST_ON)) == 0)
94 		return 0;
95 
96 	/* save the port PxFBS register for later restore */
97 	port_fbs = readl(port_mmio + PORT_FBS);
98 
99 	/* setting HBA to idle */
100 	tmp &= ~PORT_CMD_START;
101 	writel(tmp, port_mmio + PORT_CMD);
102 
103 	/*
104 	 * bit #15 PxCMD signal doesn't clear PxFBS,
105 	 * restore the PxFBS register right after clearing the PxCMD ST,
106 	 * no need to wait for the PxCMD bit #15.
107 	 */
108 	writel(port_fbs, port_mmio + PORT_FBS);
109 
110 	/* wait for engine to stop. This could be as long as 500 msec */
111 	tmp = ata_wait_register(ap, port_mmio + PORT_CMD,
112 				PORT_CMD_LIST_ON, PORT_CMD_LIST_ON, 1, 500);
113 	if (tmp & PORT_CMD_LIST_ON)
114 		return -EIO;
115 
116 	return 0;
117 }
118 
119 #ifdef CONFIG_PM_SLEEP
120 static int ahci_mvebu_suspend(struct platform_device *pdev, pm_message_t state)
121 {
122 	return ahci_platform_suspend_host(&pdev->dev);
123 }
124 
125 static int ahci_mvebu_resume(struct platform_device *pdev)
126 {
127 	struct ata_host *host = platform_get_drvdata(pdev);
128 	struct ahci_host_priv *hpriv = host->private_data;
129 	const struct mbus_dram_target_info *dram;
130 
131 	dram = mv_mbus_dram_info();
132 	if (dram)
133 		ahci_mvebu_mbus_config(hpriv, dram);
134 
135 	ahci_mvebu_regret_option(hpriv);
136 
137 	return ahci_platform_resume_host(&pdev->dev);
138 }
139 #else
140 #define ahci_mvebu_suspend NULL
141 #define ahci_mvebu_resume NULL
142 #endif
143 
144 static const struct ata_port_info ahci_mvebu_port_info = {
145 	.flags	   = AHCI_FLAG_COMMON,
146 	.pio_mask  = ATA_PIO4,
147 	.udma_mask = ATA_UDMA6,
148 	.port_ops  = &ahci_platform_ops,
149 };
150 
151 static struct scsi_host_template ahci_platform_sht = {
152 	AHCI_SHT(DRV_NAME),
153 };
154 
155 static int ahci_mvebu_probe(struct platform_device *pdev)
156 {
157 	struct ahci_host_priv *hpriv;
158 	const struct mbus_dram_target_info *dram;
159 	int rc;
160 
161 	hpriv = ahci_platform_get_resources(pdev, 0);
162 	if (IS_ERR(hpriv))
163 		return PTR_ERR(hpriv);
164 
165 	rc = ahci_platform_enable_resources(hpriv);
166 	if (rc)
167 		return rc;
168 
169 	hpriv->stop_engine = ahci_mvebu_stop_engine;
170 
171 	if (of_device_is_compatible(pdev->dev.of_node,
172 				    "marvell,armada-380-ahci")) {
173 		dram = mv_mbus_dram_info();
174 		if (!dram)
175 			return -ENODEV;
176 
177 		ahci_mvebu_mbus_config(hpriv, dram);
178 		ahci_mvebu_regret_option(hpriv);
179 	}
180 
181 	rc = ahci_platform_init_host(pdev, hpriv, &ahci_mvebu_port_info,
182 				     &ahci_platform_sht);
183 	if (rc)
184 		goto disable_resources;
185 
186 	return 0;
187 
188 disable_resources:
189 	ahci_platform_disable_resources(hpriv);
190 	return rc;
191 }
192 
193 static const struct of_device_id ahci_mvebu_of_match[] = {
194 	{ .compatible = "marvell,armada-380-ahci", },
195 	{ .compatible = "marvell,armada-3700-ahci", },
196 	{ },
197 };
198 MODULE_DEVICE_TABLE(of, ahci_mvebu_of_match);
199 
200 /*
201  * We currently don't provide power management related operations,
202  * since there is no suspend/resume support at the platform level for
203  * Armada 38x for the moment.
204  */
205 static struct platform_driver ahci_mvebu_driver = {
206 	.probe = ahci_mvebu_probe,
207 	.remove = ata_platform_remove_one,
208 	.suspend = ahci_mvebu_suspend,
209 	.resume = ahci_mvebu_resume,
210 	.driver = {
211 		.name = DRV_NAME,
212 		.of_match_table = ahci_mvebu_of_match,
213 	},
214 };
215 module_platform_driver(ahci_mvebu_driver);
216 
217 MODULE_DESCRIPTION("Marvell EBU AHCI SATA driver");
218 MODULE_AUTHOR("Thomas Petazzoni <thomas.petazzoni@free-electrons.com>, Marcin Wojtas <mw@semihalf.com>");
219 MODULE_LICENSE("GPL");
220 MODULE_ALIAS("platform:ahci_mvebu");
221