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1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * MHI PCI driver - MHI over PCI controller driver
4  *
5  * This module is a generic driver for registering MHI-over-PCI devices,
6  * such as PCIe QCOM modems.
7  *
8  * Copyright (C) 2020 Linaro Ltd <loic.poulain@linaro.org>
9  */
10 
11 #include <linux/device.h>
12 #include <linux/mhi.h>
13 #include <linux/module.h>
14 #include <linux/pci.h>
15 
16 #define MHI_PCI_DEFAULT_BAR_NUM 0
17 
18 /**
19  * struct mhi_pci_dev_info - MHI PCI device specific information
20  * @config: MHI controller configuration
21  * @name: name of the PCI module
22  * @fw: firmware path (if any)
23  * @edl: emergency download mode firmware path (if any)
24  * @bar_num: PCI base address register to use for MHI MMIO register space
25  * @dma_data_width: DMA transfer word size (32 or 64 bits)
26  */
27 struct mhi_pci_dev_info {
28 	const struct mhi_controller_config *config;
29 	const char *name;
30 	const char *fw;
31 	const char *edl;
32 	unsigned int bar_num;
33 	unsigned int dma_data_width;
34 };
35 
36 #define MHI_CHANNEL_CONFIG_UL(ch_num, ch_name, el_count, ev_ring) \
37 	{						\
38 		.num = ch_num,				\
39 		.name = ch_name,			\
40 		.num_elements = el_count,		\
41 		.event_ring = ev_ring,			\
42 		.dir = DMA_TO_DEVICE,			\
43 		.ee_mask = BIT(MHI_EE_AMSS),		\
44 		.pollcfg = 0,				\
45 		.doorbell = MHI_DB_BRST_DISABLE,	\
46 		.lpm_notify = false,			\
47 		.offload_channel = false,		\
48 		.doorbell_mode_switch = false,		\
49 	}						\
50 
51 #define MHI_CHANNEL_CONFIG_DL(ch_num, ch_name, el_count, ev_ring) \
52 	{						\
53 		.num = ch_num,				\
54 		.name = ch_name,			\
55 		.num_elements = el_count,		\
56 		.event_ring = ev_ring,			\
57 		.dir = DMA_FROM_DEVICE,			\
58 		.ee_mask = BIT(MHI_EE_AMSS),		\
59 		.pollcfg = 0,				\
60 		.doorbell = MHI_DB_BRST_DISABLE,	\
61 		.lpm_notify = false,			\
62 		.offload_channel = false,		\
63 		.doorbell_mode_switch = false,		\
64 	}
65 
66 #define MHI_EVENT_CONFIG_CTRL(ev_ring)		\
67 	{					\
68 		.num_elements = 64,		\
69 		.irq_moderation_ms = 0,		\
70 		.irq = (ev_ring) + 1,		\
71 		.priority = 1,			\
72 		.mode = MHI_DB_BRST_DISABLE,	\
73 		.data_type = MHI_ER_CTRL,	\
74 		.hardware_event = false,	\
75 		.client_managed = false,	\
76 		.offload_channel = false,	\
77 	}
78 
79 #define MHI_EVENT_CONFIG_DATA(ev_ring)		\
80 	{					\
81 		.num_elements = 128,		\
82 		.irq_moderation_ms = 5,		\
83 		.irq = (ev_ring) + 1,		\
84 		.priority = 1,			\
85 		.mode = MHI_DB_BRST_DISABLE,	\
86 		.data_type = MHI_ER_DATA,	\
87 		.hardware_event = false,	\
88 		.client_managed = false,	\
89 		.offload_channel = false,	\
90 	}
91 
92 #define MHI_EVENT_CONFIG_HW_DATA(ev_ring, ch_num) \
93 	{					\
94 		.num_elements = 128,		\
95 		.irq_moderation_ms = 5,		\
96 		.irq = (ev_ring) + 1,		\
97 		.priority = 1,			\
98 		.mode = MHI_DB_BRST_DISABLE,	\
99 		.data_type = MHI_ER_DATA,	\
100 		.hardware_event = true,		\
101 		.client_managed = false,	\
102 		.offload_channel = false,	\
103 		.channel = ch_num,		\
104 	}
105 
106 static const struct mhi_channel_config modem_qcom_v1_mhi_channels[] = {
107 	MHI_CHANNEL_CONFIG_UL(12, "MBIM", 4, 0),
108 	MHI_CHANNEL_CONFIG_DL(13, "MBIM", 4, 0),
109 	MHI_CHANNEL_CONFIG_UL(14, "QMI", 4, 0),
110 	MHI_CHANNEL_CONFIG_DL(15, "QMI", 4, 0),
111 	MHI_CHANNEL_CONFIG_UL(20, "IPCR", 8, 0),
112 	MHI_CHANNEL_CONFIG_DL(21, "IPCR", 8, 0),
113 	MHI_CHANNEL_CONFIG_UL(100, "IP_HW0", 128, 1),
114 	MHI_CHANNEL_CONFIG_DL(101, "IP_HW0", 128, 2),
115 };
116 
117 static const struct mhi_event_config modem_qcom_v1_mhi_events[] = {
118 	/* first ring is control+data ring */
119 	MHI_EVENT_CONFIG_CTRL(0),
120 	/* Hardware channels request dedicated hardware event rings */
121 	MHI_EVENT_CONFIG_HW_DATA(1, 100),
122 	MHI_EVENT_CONFIG_HW_DATA(2, 101)
123 };
124 
125 static const struct mhi_controller_config modem_qcom_v1_mhiv_config = {
126 	.max_channels = 128,
127 	.timeout_ms = 5000,
128 	.num_channels = ARRAY_SIZE(modem_qcom_v1_mhi_channels),
129 	.ch_cfg = modem_qcom_v1_mhi_channels,
130 	.num_events = ARRAY_SIZE(modem_qcom_v1_mhi_events),
131 	.event_cfg = modem_qcom_v1_mhi_events,
132 };
133 
134 static const struct mhi_pci_dev_info mhi_qcom_sdx55_info = {
135 	.name = "qcom-sdx55m",
136 	.fw = "qcom/sdx55m/sbl1.mbn",
137 	.edl = "qcom/sdx55m/edl.mbn",
138 	.config = &modem_qcom_v1_mhiv_config,
139 	.bar_num = MHI_PCI_DEFAULT_BAR_NUM,
140 	.dma_data_width = 32
141 };
142 
143 static const struct pci_device_id mhi_pci_id_table[] = {
144 	{ PCI_DEVICE(PCI_VENDOR_ID_QCOM, 0x0306),
145 		.driver_data = (kernel_ulong_t) &mhi_qcom_sdx55_info },
146 	{  }
147 };
148 MODULE_DEVICE_TABLE(pci, mhi_pci_id_table);
149 
mhi_pci_read_reg(struct mhi_controller * mhi_cntrl,void __iomem * addr,u32 * out)150 static int mhi_pci_read_reg(struct mhi_controller *mhi_cntrl,
151 			    void __iomem *addr, u32 *out)
152 {
153 	*out = readl(addr);
154 	return 0;
155 }
156 
mhi_pci_write_reg(struct mhi_controller * mhi_cntrl,void __iomem * addr,u32 val)157 static void mhi_pci_write_reg(struct mhi_controller *mhi_cntrl,
158 			      void __iomem *addr, u32 val)
159 {
160 	writel(val, addr);
161 }
162 
mhi_pci_status_cb(struct mhi_controller * mhi_cntrl,enum mhi_callback cb)163 static void mhi_pci_status_cb(struct mhi_controller *mhi_cntrl,
164 			      enum mhi_callback cb)
165 {
166 	/* Nothing to do for now */
167 }
168 
mhi_pci_claim(struct mhi_controller * mhi_cntrl,unsigned int bar_num,u64 dma_mask)169 static int mhi_pci_claim(struct mhi_controller *mhi_cntrl,
170 			 unsigned int bar_num, u64 dma_mask)
171 {
172 	struct pci_dev *pdev = to_pci_dev(mhi_cntrl->cntrl_dev);
173 	int err;
174 
175 	err = pci_assign_resource(pdev, bar_num);
176 	if (err)
177 		return err;
178 
179 	err = pcim_enable_device(pdev);
180 	if (err) {
181 		dev_err(&pdev->dev, "failed to enable pci device: %d\n", err);
182 		return err;
183 	}
184 
185 	err = pcim_iomap_regions(pdev, 1 << bar_num, pci_name(pdev));
186 	if (err) {
187 		dev_err(&pdev->dev, "failed to map pci region: %d\n", err);
188 		return err;
189 	}
190 	mhi_cntrl->regs = pcim_iomap_table(pdev)[bar_num];
191 
192 	err = pci_set_dma_mask(pdev, dma_mask);
193 	if (err) {
194 		dev_err(&pdev->dev, "Cannot set proper DMA mask\n");
195 		return err;
196 	}
197 
198 	err = pci_set_consistent_dma_mask(pdev, dma_mask);
199 	if (err) {
200 		dev_err(&pdev->dev, "set consistent dma mask failed\n");
201 		return err;
202 	}
203 
204 	pci_set_master(pdev);
205 
206 	return 0;
207 }
208 
mhi_pci_get_irqs(struct mhi_controller * mhi_cntrl,const struct mhi_controller_config * mhi_cntrl_config)209 static int mhi_pci_get_irqs(struct mhi_controller *mhi_cntrl,
210 			    const struct mhi_controller_config *mhi_cntrl_config)
211 {
212 	struct pci_dev *pdev = to_pci_dev(mhi_cntrl->cntrl_dev);
213 	int nr_vectors, i;
214 	int *irq;
215 
216 	/*
217 	 * Alloc one MSI vector for BHI + one vector per event ring, ideally...
218 	 * No explicit pci_free_irq_vectors required, done by pcim_release.
219 	 */
220 	mhi_cntrl->nr_irqs = 1 + mhi_cntrl_config->num_events;
221 
222 	nr_vectors = pci_alloc_irq_vectors(pdev, 1, mhi_cntrl->nr_irqs, PCI_IRQ_MSI);
223 	if (nr_vectors < 0) {
224 		dev_err(&pdev->dev, "Error allocating MSI vectors %d\n",
225 			nr_vectors);
226 		return nr_vectors;
227 	}
228 
229 	if (nr_vectors < mhi_cntrl->nr_irqs) {
230 		dev_warn(&pdev->dev, "Not enough MSI vectors (%d/%d), use shared MSI\n",
231 			 nr_vectors, mhi_cntrl_config->num_events);
232 	}
233 
234 	irq = devm_kcalloc(&pdev->dev, mhi_cntrl->nr_irqs, sizeof(int), GFP_KERNEL);
235 	if (!irq)
236 		return -ENOMEM;
237 
238 	for (i = 0; i < mhi_cntrl->nr_irqs; i++) {
239 		int vector = i >= nr_vectors ? (nr_vectors - 1) : i;
240 
241 		irq[i] = pci_irq_vector(pdev, vector);
242 	}
243 
244 	mhi_cntrl->irq = irq;
245 
246 	return 0;
247 }
248 
mhi_pci_runtime_get(struct mhi_controller * mhi_cntrl)249 static int mhi_pci_runtime_get(struct mhi_controller *mhi_cntrl)
250 {
251 	/* no PM for now */
252 	return 0;
253 }
254 
mhi_pci_runtime_put(struct mhi_controller * mhi_cntrl)255 static void mhi_pci_runtime_put(struct mhi_controller *mhi_cntrl)
256 {
257 	/* no PM for now */
258 }
259 
mhi_pci_probe(struct pci_dev * pdev,const struct pci_device_id * id)260 static int mhi_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
261 {
262 	const struct mhi_pci_dev_info *info = (struct mhi_pci_dev_info *) id->driver_data;
263 	const struct mhi_controller_config *mhi_cntrl_config;
264 	struct mhi_controller *mhi_cntrl;
265 	int err;
266 
267 	dev_dbg(&pdev->dev, "MHI PCI device found: %s\n", info->name);
268 
269 	mhi_cntrl = mhi_alloc_controller();
270 	if (!mhi_cntrl)
271 		return -ENOMEM;
272 
273 	mhi_cntrl_config = info->config;
274 	mhi_cntrl->cntrl_dev = &pdev->dev;
275 	mhi_cntrl->iova_start = 0;
276 	mhi_cntrl->iova_stop = (dma_addr_t)DMA_BIT_MASK(info->dma_data_width);
277 	mhi_cntrl->fw_image = info->fw;
278 	mhi_cntrl->edl_image = info->edl;
279 
280 	mhi_cntrl->read_reg = mhi_pci_read_reg;
281 	mhi_cntrl->write_reg = mhi_pci_write_reg;
282 	mhi_cntrl->status_cb = mhi_pci_status_cb;
283 	mhi_cntrl->runtime_get = mhi_pci_runtime_get;
284 	mhi_cntrl->runtime_put = mhi_pci_runtime_put;
285 
286 	err = mhi_pci_claim(mhi_cntrl, info->bar_num, DMA_BIT_MASK(info->dma_data_width));
287 	if (err)
288 		goto err_release;
289 
290 	err = mhi_pci_get_irqs(mhi_cntrl, mhi_cntrl_config);
291 	if (err)
292 		goto err_release;
293 
294 	pci_set_drvdata(pdev, mhi_cntrl);
295 
296 	err = mhi_register_controller(mhi_cntrl, mhi_cntrl_config);
297 	if (err)
298 		goto err_release;
299 
300 	/* MHI bus does not power up the controller by default */
301 	err = mhi_prepare_for_power_up(mhi_cntrl);
302 	if (err) {
303 		dev_err(&pdev->dev, "failed to prepare MHI controller\n");
304 		goto err_unregister;
305 	}
306 
307 	err = mhi_sync_power_up(mhi_cntrl);
308 	if (err) {
309 		dev_err(&pdev->dev, "failed to power up MHI controller\n");
310 		goto err_unprepare;
311 	}
312 
313 	return 0;
314 
315 err_unprepare:
316 	mhi_unprepare_after_power_down(mhi_cntrl);
317 err_unregister:
318 	mhi_unregister_controller(mhi_cntrl);
319 err_release:
320 	mhi_free_controller(mhi_cntrl);
321 
322 	return err;
323 }
324 
mhi_pci_remove(struct pci_dev * pdev)325 static void mhi_pci_remove(struct pci_dev *pdev)
326 {
327 	struct mhi_controller *mhi_cntrl = pci_get_drvdata(pdev);
328 
329 	mhi_power_down(mhi_cntrl, true);
330 	mhi_unprepare_after_power_down(mhi_cntrl);
331 	mhi_unregister_controller(mhi_cntrl);
332 	mhi_free_controller(mhi_cntrl);
333 }
334 
335 static struct pci_driver mhi_pci_driver = {
336 	.name		= "mhi-pci-generic",
337 	.id_table	= mhi_pci_id_table,
338 	.probe		= mhi_pci_probe,
339 	.remove		= mhi_pci_remove
340 };
341 module_pci_driver(mhi_pci_driver);
342 
343 MODULE_AUTHOR("Loic Poulain <loic.poulain@linaro.org>");
344 MODULE_DESCRIPTION("Modem Host Interface (MHI) PCI controller driver");
345 MODULE_LICENSE("GPL");
346