xref: /kernel/linux/linux-6.6/drivers/uio/uio_pruss.c (revision 62306a36)
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Programmable Real-Time Unit Sub System (PRUSS) UIO driver (uio_pruss)
4 *
5 * This driver exports PRUSS host event out interrupts and PRUSS, L3 RAM,
6 * and DDR RAM to user space for applications interacting with PRUSS firmware
7 *
8 * Copyright (C) 2010-11 Texas Instruments Incorporated - http://www.ti.com/
9 */
10#include <linux/device.h>
11#include <linux/module.h>
12#include <linux/moduleparam.h>
13#include <linux/platform_device.h>
14#include <linux/uio_driver.h>
15#include <linux/platform_data/uio_pruss.h>
16#include <linux/io.h>
17#include <linux/clk.h>
18#include <linux/dma-mapping.h>
19#include <linux/sizes.h>
20#include <linux/slab.h>
21#include <linux/genalloc.h>
22
23#define DRV_NAME "pruss_uio"
24#define DRV_VERSION "1.0"
25
26static int sram_pool_sz = SZ_16K;
27module_param(sram_pool_sz, int, 0);
28MODULE_PARM_DESC(sram_pool_sz, "sram pool size to allocate ");
29
30static int extram_pool_sz = SZ_256K;
31module_param(extram_pool_sz, int, 0);
32MODULE_PARM_DESC(extram_pool_sz, "external ram pool size to allocate");
33
34/*
35 * Host event IRQ numbers from PRUSS - PRUSS can generate up to 8 interrupt
36 * events to AINTC of ARM host processor - which can be used for IPC b/w PRUSS
37 * firmware and user space application, async notification from PRU firmware
38 * to user space application
39 * 3	PRU_EVTOUT0
40 * 4	PRU_EVTOUT1
41 * 5	PRU_EVTOUT2
42 * 6	PRU_EVTOUT3
43 * 7	PRU_EVTOUT4
44 * 8	PRU_EVTOUT5
45 * 9	PRU_EVTOUT6
46 * 10	PRU_EVTOUT7
47*/
48#define MAX_PRUSS_EVT	8
49
50#define PINTC_HIDISR	0x0038
51#define PINTC_HIPIR	0x0900
52#define HIPIR_NOPEND	0x80000000
53#define PINTC_HIER	0x1500
54
55struct uio_pruss_dev {
56	struct uio_info *info;
57	struct clk *pruss_clk;
58	dma_addr_t sram_paddr;
59	dma_addr_t ddr_paddr;
60	void __iomem *prussio_vaddr;
61	unsigned long sram_vaddr;
62	void *ddr_vaddr;
63	unsigned int hostirq_start;
64	unsigned int pintc_base;
65	struct gen_pool *sram_pool;
66};
67
68static irqreturn_t pruss_handler(int irq, struct uio_info *info)
69{
70	struct uio_pruss_dev *gdev = info->priv;
71	int intr_bit = (irq - gdev->hostirq_start + 2);
72	int val, intr_mask = (1 << intr_bit);
73	void __iomem *base = gdev->prussio_vaddr + gdev->pintc_base;
74	void __iomem *intren_reg = base + PINTC_HIER;
75	void __iomem *intrdis_reg = base + PINTC_HIDISR;
76	void __iomem *intrstat_reg = base + PINTC_HIPIR + (intr_bit << 2);
77
78	val = ioread32(intren_reg);
79	/* Is interrupt enabled and active ? */
80	if (!(val & intr_mask) && (ioread32(intrstat_reg) & HIPIR_NOPEND))
81		return IRQ_NONE;
82	/* Disable interrupt */
83	iowrite32(intr_bit, intrdis_reg);
84	return IRQ_HANDLED;
85}
86
87static void pruss_cleanup(struct device *dev, struct uio_pruss_dev *gdev)
88{
89	int cnt;
90	struct uio_info *p = gdev->info;
91
92	for (cnt = 0; cnt < MAX_PRUSS_EVT; cnt++, p++) {
93		uio_unregister_device(p);
94	}
95	iounmap(gdev->prussio_vaddr);
96	if (gdev->ddr_vaddr) {
97		dma_free_coherent(dev, extram_pool_sz, gdev->ddr_vaddr,
98			gdev->ddr_paddr);
99	}
100	if (gdev->sram_vaddr)
101		gen_pool_free(gdev->sram_pool,
102			      gdev->sram_vaddr,
103			      sram_pool_sz);
104	clk_disable(gdev->pruss_clk);
105}
106
107static int pruss_probe(struct platform_device *pdev)
108{
109	struct uio_info *p;
110	struct uio_pruss_dev *gdev;
111	struct resource *regs_prussio;
112	struct device *dev = &pdev->dev;
113	int ret, cnt, i, len;
114	struct uio_pruss_pdata *pdata = dev_get_platdata(dev);
115
116	gdev = devm_kzalloc(dev, sizeof(struct uio_pruss_dev), GFP_KERNEL);
117	if (!gdev)
118		return -ENOMEM;
119
120	gdev->info = devm_kcalloc(dev, MAX_PRUSS_EVT, sizeof(*p), GFP_KERNEL);
121	if (!gdev->info)
122		return -ENOMEM;
123
124	/* Power on PRU in case its not done as part of boot-loader */
125	gdev->pruss_clk = devm_clk_get(dev, "pruss");
126	if (IS_ERR(gdev->pruss_clk)) {
127		dev_err(dev, "Failed to get clock\n");
128		return PTR_ERR(gdev->pruss_clk);
129	}
130
131	ret = clk_enable(gdev->pruss_clk);
132	if (ret) {
133		dev_err(dev, "Failed to enable clock\n");
134		return ret;
135	}
136
137	regs_prussio = platform_get_resource(pdev, IORESOURCE_MEM, 0);
138	if (!regs_prussio) {
139		dev_err(dev, "No PRUSS I/O resource specified\n");
140		ret = -EIO;
141		goto err_clk_disable;
142	}
143
144	if (!regs_prussio->start) {
145		dev_err(dev, "Invalid memory resource\n");
146		ret = -EIO;
147		goto err_clk_disable;
148	}
149
150	if (pdata->sram_pool) {
151		gdev->sram_pool = pdata->sram_pool;
152		gdev->sram_vaddr =
153			(unsigned long)gen_pool_dma_alloc(gdev->sram_pool,
154					sram_pool_sz, &gdev->sram_paddr);
155		if (!gdev->sram_vaddr) {
156			dev_err(dev, "Could not allocate SRAM pool\n");
157			ret = -ENOMEM;
158			goto err_clk_disable;
159		}
160	}
161
162	gdev->ddr_vaddr = dma_alloc_coherent(dev, extram_pool_sz,
163				&(gdev->ddr_paddr), GFP_KERNEL | GFP_DMA);
164	if (!gdev->ddr_vaddr) {
165		dev_err(dev, "Could not allocate external memory\n");
166		ret = -ENOMEM;
167		goto err_free_sram;
168	}
169
170	len = resource_size(regs_prussio);
171	gdev->prussio_vaddr = ioremap(regs_prussio->start, len);
172	if (!gdev->prussio_vaddr) {
173		dev_err(dev, "Can't remap PRUSS I/O  address range\n");
174		ret = -ENOMEM;
175		goto err_free_ddr_vaddr;
176	}
177
178	ret = platform_get_irq(pdev, 0);
179	if (ret < 0)
180		goto err_unmap;
181
182	gdev->hostirq_start = ret;
183	gdev->pintc_base = pdata->pintc_base;
184
185	for (cnt = 0, p = gdev->info; cnt < MAX_PRUSS_EVT; cnt++, p++) {
186		p->mem[0].addr = regs_prussio->start;
187		p->mem[0].size = resource_size(regs_prussio);
188		p->mem[0].memtype = UIO_MEM_PHYS;
189
190		p->mem[1].addr = gdev->sram_paddr;
191		p->mem[1].size = sram_pool_sz;
192		p->mem[1].memtype = UIO_MEM_PHYS;
193
194		p->mem[2].addr = gdev->ddr_paddr;
195		p->mem[2].size = extram_pool_sz;
196		p->mem[2].memtype = UIO_MEM_PHYS;
197
198		p->name = devm_kasprintf(dev, GFP_KERNEL, "pruss_evt%d", cnt);
199		p->version = DRV_VERSION;
200
201		/* Register PRUSS IRQ lines */
202		p->irq = gdev->hostirq_start + cnt;
203		p->handler = pruss_handler;
204		p->priv = gdev;
205
206		ret = uio_register_device(dev, p);
207		if (ret < 0)
208			goto err_unloop;
209	}
210
211	platform_set_drvdata(pdev, gdev);
212	return 0;
213
214err_unloop:
215	for (i = 0, p = gdev->info; i < cnt; i++, p++) {
216		uio_unregister_device(p);
217	}
218err_unmap:
219	iounmap(gdev->prussio_vaddr);
220err_free_ddr_vaddr:
221	dma_free_coherent(dev, extram_pool_sz, gdev->ddr_vaddr,
222			  gdev->ddr_paddr);
223err_free_sram:
224	if (pdata->sram_pool)
225		gen_pool_free(gdev->sram_pool, gdev->sram_vaddr, sram_pool_sz);
226err_clk_disable:
227	clk_disable(gdev->pruss_clk);
228
229	return ret;
230}
231
232static int pruss_remove(struct platform_device *dev)
233{
234	struct uio_pruss_dev *gdev = platform_get_drvdata(dev);
235
236	pruss_cleanup(&dev->dev, gdev);
237	return 0;
238}
239
240static struct platform_driver pruss_driver = {
241	.probe = pruss_probe,
242	.remove = pruss_remove,
243	.driver = {
244		   .name = DRV_NAME,
245		   },
246};
247
248module_platform_driver(pruss_driver);
249
250MODULE_LICENSE("GPL v2");
251MODULE_VERSION(DRV_VERSION);
252MODULE_AUTHOR("Amit Chatterjee <amit.chatterjee@ti.com>");
253MODULE_AUTHOR("Pratheesh Gangadhar <pratheesh@ti.com>");
254