1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2020, Broadcom */
3
4 #include <linux/clk.h>
5 #include <linux/dma-mapping.h>
6 #include <linux/err.h>
7 #include <linux/kernel.h>
8 #include <linux/io.h>
9 #include <linux/module.h>
10 #include <linux/platform_device.h>
11 #include <linux/usb.h>
12 #include <linux/usb/hcd.h>
13 #include <linux/iopoll.h>
14
15 #include "ehci.h"
16
17 #define hcd_to_ehci_priv(h) ((struct brcm_priv *)hcd_to_ehci(h)->priv)
18
19 struct brcm_priv {
20 struct clk *clk;
21 };
22
23 /*
24 * ehci_brcm_wait_for_sof
25 * Wait for start of next microframe, then wait extra delay microseconds
26 */
ehci_brcm_wait_for_sof(struct ehci_hcd * ehci,u32 delay)27 static inline void ehci_brcm_wait_for_sof(struct ehci_hcd *ehci, u32 delay)
28 {
29 u32 frame_idx = ehci_readl(ehci, &ehci->regs->frame_index);
30 u32 val;
31 int res;
32
33 /* Wait for next microframe (every 125 usecs) */
34 res = readl_relaxed_poll_timeout(&ehci->regs->frame_index, val,
35 val != frame_idx, 1, 130);
36 if (res)
37 ehci_err(ehci, "Error waiting for SOF\n");
38 udelay(delay);
39 }
40
41 /*
42 * ehci_brcm_hub_control
43 * The EHCI controller has a bug where it can violate the SOF
44 * interval between the first two SOF's transmitted after resume
45 * if the resume occurs near the end of the microframe. This causees
46 * the controller to detect babble on the suspended port and
47 * will eventually cause the controller to reset the port.
48 * The fix is to Intercept the echi-hcd request to complete RESUME and
49 * align it to the start of the next microframe.
50 * See SWLINUX-1909 for more details
51 */
ehci_brcm_hub_control(struct usb_hcd * hcd,u16 typeReq,u16 wValue,u16 wIndex,char * buf,u16 wLength)52 static int ehci_brcm_hub_control(
53 struct usb_hcd *hcd,
54 u16 typeReq,
55 u16 wValue,
56 u16 wIndex,
57 char *buf,
58 u16 wLength)
59 {
60 struct ehci_hcd *ehci = hcd_to_ehci(hcd);
61 int ports = HCS_N_PORTS(ehci->hcs_params);
62 u32 __iomem *status_reg;
63 unsigned long flags;
64 int retval, irq_disabled = 0;
65 u32 temp;
66
67 temp = (wIndex & 0xff) - 1;
68 if (temp >= HCS_N_PORTS_MAX) /* Avoid index-out-of-bounds warning */
69 temp = 0;
70 status_reg = &ehci->regs->port_status[temp];
71
72 /*
73 * RESUME is cleared when GetPortStatus() is called 20ms after start
74 * of RESUME
75 */
76 if ((typeReq == GetPortStatus) &&
77 (wIndex && wIndex <= ports) &&
78 ehci->reset_done[wIndex-1] &&
79 time_after_eq(jiffies, ehci->reset_done[wIndex-1]) &&
80 (ehci_readl(ehci, status_reg) & PORT_RESUME)) {
81
82 /*
83 * to make sure we are not interrupted until RESUME bit
84 * is cleared, disable interrupts on current CPU
85 */
86 ehci_dbg(ehci, "SOF alignment workaround\n");
87 irq_disabled = 1;
88 local_irq_save(flags);
89 ehci_brcm_wait_for_sof(ehci, 5);
90 }
91 retval = ehci_hub_control(hcd, typeReq, wValue, wIndex, buf, wLength);
92 if (irq_disabled)
93 local_irq_restore(flags);
94 return retval;
95 }
96
ehci_brcm_reset(struct usb_hcd * hcd)97 static int ehci_brcm_reset(struct usb_hcd *hcd)
98 {
99 struct ehci_hcd *ehci = hcd_to_ehci(hcd);
100 int len;
101
102 ehci->big_endian_mmio = 1;
103
104 ehci->caps = (void __iomem *)hcd->regs;
105 len = HC_LENGTH(ehci, ehci_readl(ehci, &ehci->caps->hc_capbase));
106 ehci->regs = (void __iomem *)(hcd->regs + len);
107
108 /* This fixes the lockup during reboot due to prior interrupts */
109 ehci_writel(ehci, CMD_RESET, &ehci->regs->command);
110 mdelay(10);
111
112 /*
113 * SWLINUX-1705: Avoid OUT packet underflows during high memory
114 * bus usage
115 */
116 ehci_writel(ehci, 0x00800040, &ehci->regs->brcm_insnreg[1]);
117 ehci_writel(ehci, 0x00000001, &ehci->regs->brcm_insnreg[3]);
118
119 return ehci_setup(hcd);
120 }
121
122 static struct hc_driver __read_mostly ehci_brcm_hc_driver;
123
124 static const struct ehci_driver_overrides brcm_overrides __initconst = {
125 .reset = ehci_brcm_reset,
126 .extra_priv_size = sizeof(struct brcm_priv),
127 };
128
ehci_brcm_probe(struct platform_device * pdev)129 static int ehci_brcm_probe(struct platform_device *pdev)
130 {
131 struct device *dev = &pdev->dev;
132 struct resource *res_mem;
133 struct brcm_priv *priv;
134 struct usb_hcd *hcd;
135 int irq;
136 int err;
137
138 err = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32));
139 if (err)
140 return err;
141
142 irq = platform_get_irq(pdev, 0);
143 if (irq < 0)
144 return irq;
145
146 /* Hook the hub control routine to work around a bug */
147 ehci_brcm_hc_driver.hub_control = ehci_brcm_hub_control;
148
149 /* initialize hcd */
150 hcd = usb_create_hcd(&ehci_brcm_hc_driver, dev, dev_name(dev));
151 if (!hcd)
152 return -ENOMEM;
153
154 platform_set_drvdata(pdev, hcd);
155 priv = hcd_to_ehci_priv(hcd);
156
157 priv->clk = devm_clk_get_optional(dev, NULL);
158 if (IS_ERR(priv->clk)) {
159 err = PTR_ERR(priv->clk);
160 goto err_hcd;
161 }
162
163 err = clk_prepare_enable(priv->clk);
164 if (err)
165 goto err_hcd;
166
167 hcd->regs = devm_platform_get_and_ioremap_resource(pdev, 0, &res_mem);
168 if (IS_ERR(hcd->regs)) {
169 err = PTR_ERR(hcd->regs);
170 goto err_clk;
171 }
172 hcd->rsrc_start = res_mem->start;
173 hcd->rsrc_len = resource_size(res_mem);
174 err = usb_add_hcd(hcd, irq, IRQF_SHARED);
175 if (err)
176 goto err_clk;
177
178 device_wakeup_enable(hcd->self.controller);
179 device_enable_async_suspend(hcd->self.controller);
180
181 return 0;
182
183 err_clk:
184 clk_disable_unprepare(priv->clk);
185 err_hcd:
186 usb_put_hcd(hcd);
187
188 return err;
189 }
190
ehci_brcm_remove(struct platform_device * dev)191 static void ehci_brcm_remove(struct platform_device *dev)
192 {
193 struct usb_hcd *hcd = platform_get_drvdata(dev);
194 struct brcm_priv *priv = hcd_to_ehci_priv(hcd);
195
196 usb_remove_hcd(hcd);
197 clk_disable_unprepare(priv->clk);
198 usb_put_hcd(hcd);
199 }
200
ehci_brcm_suspend(struct device * dev)201 static int __maybe_unused ehci_brcm_suspend(struct device *dev)
202 {
203 int ret;
204 struct usb_hcd *hcd = dev_get_drvdata(dev);
205 struct brcm_priv *priv = hcd_to_ehci_priv(hcd);
206 bool do_wakeup = device_may_wakeup(dev);
207
208 ret = ehci_suspend(hcd, do_wakeup);
209 if (ret)
210 return ret;
211 clk_disable_unprepare(priv->clk);
212 return 0;
213 }
214
ehci_brcm_resume(struct device * dev)215 static int __maybe_unused ehci_brcm_resume(struct device *dev)
216 {
217 struct usb_hcd *hcd = dev_get_drvdata(dev);
218 struct ehci_hcd *ehci = hcd_to_ehci(hcd);
219 struct brcm_priv *priv = hcd_to_ehci_priv(hcd);
220 int err;
221
222 err = clk_prepare_enable(priv->clk);
223 if (err)
224 return err;
225 /*
226 * SWLINUX-1705: Avoid OUT packet underflows during high memory
227 * bus usage
228 */
229 ehci_writel(ehci, 0x00800040, &ehci->regs->brcm_insnreg[1]);
230 ehci_writel(ehci, 0x00000001, &ehci->regs->brcm_insnreg[3]);
231
232 ehci_resume(hcd, false);
233
234 pm_runtime_disable(dev);
235 pm_runtime_set_active(dev);
236 pm_runtime_enable(dev);
237
238 return 0;
239 }
240
241 static SIMPLE_DEV_PM_OPS(ehci_brcm_pm_ops, ehci_brcm_suspend,
242 ehci_brcm_resume);
243
244 static const struct of_device_id brcm_ehci_of_match[] = {
245 { .compatible = "brcm,ehci-brcm-v2", },
246 { .compatible = "brcm,bcm7445-ehci", },
247 {}
248 };
249
250 static struct platform_driver ehci_brcm_driver = {
251 .probe = ehci_brcm_probe,
252 .remove_new = ehci_brcm_remove,
253 .shutdown = usb_hcd_platform_shutdown,
254 .driver = {
255 .name = "ehci-brcm",
256 .pm = &ehci_brcm_pm_ops,
257 .of_match_table = brcm_ehci_of_match,
258 }
259 };
260
ehci_brcm_init(void)261 static int __init ehci_brcm_init(void)
262 {
263 if (usb_disabled())
264 return -ENODEV;
265
266 ehci_init_driver(&ehci_brcm_hc_driver, &brcm_overrides);
267 return platform_driver_register(&ehci_brcm_driver);
268 }
269 module_init(ehci_brcm_init);
270
ehci_brcm_exit(void)271 static void __exit ehci_brcm_exit(void)
272 {
273 platform_driver_unregister(&ehci_brcm_driver);
274 }
275 module_exit(ehci_brcm_exit);
276
277 MODULE_ALIAS("platform:ehci-brcm");
278 MODULE_DESCRIPTION("EHCI Broadcom STB driver");
279 MODULE_AUTHOR("Al Cooper");
280 MODULE_LICENSE("GPL");
281
