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
66 status_reg = &ehci->regs->port_status[(wIndex & 0xff) - 1];
67
68 /*
69 * RESUME is cleared when GetPortStatus() is called 20ms after start
70 * of RESUME
71 */
72 if ((typeReq == GetPortStatus) &&
73 (wIndex && wIndex <= ports) &&
74 ehci->reset_done[wIndex-1] &&
75 time_after_eq(jiffies, ehci->reset_done[wIndex-1]) &&
76 (ehci_readl(ehci, status_reg) & PORT_RESUME)) {
77
78 /*
79 * to make sure we are not interrupted until RESUME bit
80 * is cleared, disable interrupts on current CPU
81 */
82 ehci_dbg(ehci, "SOF alignment workaround\n");
83 irq_disabled = 1;
84 local_irq_save(flags);
85 ehci_brcm_wait_for_sof(ehci, 5);
86 }
87 retval = ehci_hub_control(hcd, typeReq, wValue, wIndex, buf, wLength);
88 if (irq_disabled)
89 local_irq_restore(flags);
90 return retval;
91 }
92
ehci_brcm_reset(struct usb_hcd * hcd)93 static int ehci_brcm_reset(struct usb_hcd *hcd)
94 {
95 struct ehci_hcd *ehci = hcd_to_ehci(hcd);
96 int len;
97
98 ehci->big_endian_mmio = 1;
99
100 ehci->caps = (void __iomem *)hcd->regs;
101 len = HC_LENGTH(ehci, ehci_readl(ehci, &ehci->caps->hc_capbase));
102 ehci->regs = (void __iomem *)(hcd->regs + len);
103
104 /* This fixes the lockup during reboot due to prior interrupts */
105 ehci_writel(ehci, CMD_RESET, &ehci->regs->command);
106 mdelay(10);
107
108 /*
109 * SWLINUX-1705: Avoid OUT packet underflows during high memory
110 * bus usage
111 * port_status[0x0f] = Broadcom-proprietary USB_EHCI_INSNREG00 @ 0x90
112 */
113 ehci_writel(ehci, 0x00800040, &ehci->regs->port_status[0x10]);
114 ehci_writel(ehci, 0x00000001, &ehci->regs->port_status[0x12]);
115
116 return ehci_setup(hcd);
117 }
118
119 static struct hc_driver __read_mostly ehci_brcm_hc_driver;
120
121 static const struct ehci_driver_overrides brcm_overrides __initconst = {
122 .reset = ehci_brcm_reset,
123 .extra_priv_size = sizeof(struct brcm_priv),
124 };
125
ehci_brcm_probe(struct platform_device * pdev)126 static int ehci_brcm_probe(struct platform_device *pdev)
127 {
128 struct device *dev = &pdev->dev;
129 struct resource *res_mem;
130 struct brcm_priv *priv;
131 struct usb_hcd *hcd;
132 int irq;
133 int err;
134
135 err = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32));
136 if (err)
137 return err;
138
139 irq = platform_get_irq(pdev, 0);
140 if (irq <= 0)
141 return irq ? irq : -EINVAL;
142
143 /* Hook the hub control routine to work around a bug */
144 ehci_brcm_hc_driver.hub_control = ehci_brcm_hub_control;
145
146 /* initialize hcd */
147 hcd = usb_create_hcd(&ehci_brcm_hc_driver, dev, dev_name(dev));
148 if (!hcd)
149 return -ENOMEM;
150
151 platform_set_drvdata(pdev, hcd);
152 priv = hcd_to_ehci_priv(hcd);
153
154 priv->clk = devm_clk_get_optional(dev, NULL);
155 if (IS_ERR(priv->clk)) {
156 err = PTR_ERR(priv->clk);
157 goto err_hcd;
158 }
159
160 err = clk_prepare_enable(priv->clk);
161 if (err)
162 goto err_hcd;
163
164 hcd->regs = devm_platform_get_and_ioremap_resource(pdev, 0, &res_mem);
165 if (IS_ERR(hcd->regs)) {
166 err = PTR_ERR(hcd->regs);
167 goto err_clk;
168 }
169 hcd->rsrc_start = res_mem->start;
170 hcd->rsrc_len = resource_size(res_mem);
171 err = usb_add_hcd(hcd, irq, IRQF_SHARED);
172 if (err)
173 goto err_clk;
174
175 device_wakeup_enable(hcd->self.controller);
176 device_enable_async_suspend(hcd->self.controller);
177
178 return 0;
179
180 err_clk:
181 clk_disable_unprepare(priv->clk);
182 err_hcd:
183 usb_put_hcd(hcd);
184
185 return err;
186 }
187
ehci_brcm_remove(struct platform_device * dev)188 static int ehci_brcm_remove(struct platform_device *dev)
189 {
190 struct usb_hcd *hcd = platform_get_drvdata(dev);
191 struct brcm_priv *priv = hcd_to_ehci_priv(hcd);
192
193 usb_remove_hcd(hcd);
194 clk_disable_unprepare(priv->clk);
195 usb_put_hcd(hcd);
196 return 0;
197 }
198
ehci_brcm_suspend(struct device * dev)199 static int __maybe_unused ehci_brcm_suspend(struct device *dev)
200 {
201 int ret;
202 struct usb_hcd *hcd = dev_get_drvdata(dev);
203 struct brcm_priv *priv = hcd_to_ehci_priv(hcd);
204 bool do_wakeup = device_may_wakeup(dev);
205
206 ret = ehci_suspend(hcd, do_wakeup);
207 if (ret)
208 return ret;
209 clk_disable_unprepare(priv->clk);
210 return 0;
211 }
212
ehci_brcm_resume(struct device * dev)213 static int __maybe_unused ehci_brcm_resume(struct device *dev)
214 {
215 struct usb_hcd *hcd = dev_get_drvdata(dev);
216 struct ehci_hcd *ehci = hcd_to_ehci(hcd);
217 struct brcm_priv *priv = hcd_to_ehci_priv(hcd);
218 int err;
219
220 err = clk_prepare_enable(priv->clk);
221 if (err)
222 return err;
223 /*
224 * SWLINUX-1705: Avoid OUT packet underflows during high memory
225 * bus usage
226 * port_status[0x0f] = Broadcom-proprietary USB_EHCI_INSNREG00
227 * @ 0x90
228 */
229 ehci_writel(ehci, 0x00800040, &ehci->regs->port_status[0x10]);
230 ehci_writel(ehci, 0x00000001, &ehci->regs->port_status[0x12]);
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 = 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