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 */
112 ehci_writel(ehci, 0x00800040, &ehci->regs->brcm_insnreg[1]);
113 ehci_writel(ehci, 0x00000001, &ehci->regs->brcm_insnreg[3]);
114
115 return ehci_setup(hcd);
116 }
117
118 static struct hc_driver __read_mostly ehci_brcm_hc_driver;
119
120 static const struct ehci_driver_overrides brcm_overrides __initconst = {
121 .reset = ehci_brcm_reset,
122 .extra_priv_size = sizeof(struct brcm_priv),
123 };
124
ehci_brcm_probe(struct platform_device * pdev)125 static int ehci_brcm_probe(struct platform_device *pdev)
126 {
127 struct device *dev = &pdev->dev;
128 struct resource *res_mem;
129 struct brcm_priv *priv;
130 struct usb_hcd *hcd;
131 int irq;
132 int err;
133
134 err = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32));
135 if (err)
136 return err;
137
138 irq = platform_get_irq(pdev, 0);
139 if (irq <= 0)
140 return irq ? irq : -EINVAL;
141
142 /* Hook the hub control routine to work around a bug */
143 ehci_brcm_hc_driver.hub_control = ehci_brcm_hub_control;
144
145 /* initialize hcd */
146 hcd = usb_create_hcd(&ehci_brcm_hc_driver, dev, dev_name(dev));
147 if (!hcd)
148 return -ENOMEM;
149
150 platform_set_drvdata(pdev, hcd);
151 priv = hcd_to_ehci_priv(hcd);
152
153 priv->clk = devm_clk_get_optional(dev, NULL);
154 if (IS_ERR(priv->clk)) {
155 err = PTR_ERR(priv->clk);
156 goto err_hcd;
157 }
158
159 err = clk_prepare_enable(priv->clk);
160 if (err)
161 goto err_hcd;
162
163 hcd->regs = devm_platform_get_and_ioremap_resource(pdev, 0, &res_mem);
164 if (IS_ERR(hcd->regs)) {
165 err = PTR_ERR(hcd->regs);
166 goto err_clk;
167 }
168 hcd->rsrc_start = res_mem->start;
169 hcd->rsrc_len = resource_size(res_mem);
170 err = usb_add_hcd(hcd, irq, IRQF_SHARED);
171 if (err)
172 goto err_clk;
173
174 device_wakeup_enable(hcd->self.controller);
175 device_enable_async_suspend(hcd->self.controller);
176
177 return 0;
178
179 err_clk:
180 clk_disable_unprepare(priv->clk);
181 err_hcd:
182 usb_put_hcd(hcd);
183
184 return err;
185 }
186
ehci_brcm_remove(struct platform_device * dev)187 static int ehci_brcm_remove(struct platform_device *dev)
188 {
189 struct usb_hcd *hcd = platform_get_drvdata(dev);
190 struct brcm_priv *priv = hcd_to_ehci_priv(hcd);
191
192 usb_remove_hcd(hcd);
193 clk_disable_unprepare(priv->clk);
194 usb_put_hcd(hcd);
195 return 0;
196 }
197
ehci_brcm_suspend(struct device * dev)198 static int __maybe_unused ehci_brcm_suspend(struct device *dev)
199 {
200 int ret;
201 struct usb_hcd *hcd = dev_get_drvdata(dev);
202 struct brcm_priv *priv = hcd_to_ehci_priv(hcd);
203 bool do_wakeup = device_may_wakeup(dev);
204
205 ret = ehci_suspend(hcd, do_wakeup);
206 if (ret)
207 return ret;
208 clk_disable_unprepare(priv->clk);
209 return 0;
210 }
211
ehci_brcm_resume(struct device * dev)212 static int __maybe_unused ehci_brcm_resume(struct device *dev)
213 {
214 struct usb_hcd *hcd = dev_get_drvdata(dev);
215 struct ehci_hcd *ehci = hcd_to_ehci(hcd);
216 struct brcm_priv *priv = hcd_to_ehci_priv(hcd);
217 int err;
218
219 err = clk_prepare_enable(priv->clk);
220 if (err)
221 return err;
222 /*
223 * SWLINUX-1705: Avoid OUT packet underflows during high memory
224 * bus usage
225 */
226 ehci_writel(ehci, 0x00800040, &ehci->regs->brcm_insnreg[1]);
227 ehci_writel(ehci, 0x00000001, &ehci->regs->brcm_insnreg[3]);
228
229 ehci_resume(hcd, false);
230
231 pm_runtime_disable(dev);
232 pm_runtime_set_active(dev);
233 pm_runtime_enable(dev);
234
235 return 0;
236 }
237
238 static SIMPLE_DEV_PM_OPS(ehci_brcm_pm_ops, ehci_brcm_suspend,
239 ehci_brcm_resume);
240
241 static const struct of_device_id brcm_ehci_of_match[] = {
242 { .compatible = "brcm,ehci-brcm-v2", },
243 { .compatible = "brcm,bcm7445-ehci", },
244 {}
245 };
246
247 static struct platform_driver ehci_brcm_driver = {
248 .probe = ehci_brcm_probe,
249 .remove = ehci_brcm_remove,
250 .shutdown = usb_hcd_platform_shutdown,
251 .driver = {
252 .name = "ehci-brcm",
253 .pm = &ehci_brcm_pm_ops,
254 .of_match_table = brcm_ehci_of_match,
255 }
256 };
257
ehci_brcm_init(void)258 static int __init ehci_brcm_init(void)
259 {
260 if (usb_disabled())
261 return -ENODEV;
262
263 ehci_init_driver(&ehci_brcm_hc_driver, &brcm_overrides);
264 return platform_driver_register(&ehci_brcm_driver);
265 }
266 module_init(ehci_brcm_init);
267
ehci_brcm_exit(void)268 static void __exit ehci_brcm_exit(void)
269 {
270 platform_driver_unregister(&ehci_brcm_driver);
271 }
272 module_exit(ehci_brcm_exit);
273
274 MODULE_ALIAS("platform:ehci-brcm");
275 MODULE_DESCRIPTION("EHCI Broadcom STB driver");
276 MODULE_AUTHOR("Al Cooper");
277 MODULE_LICENSE("GPL");
278
