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(info: p);
94 }
95 iounmap(addr: gdev->prussio_vaddr);
96 if (gdev->ddr_vaddr) {
97 dma_free_coherent(dev, size: extram_pool_sz, cpu_addr: gdev->ddr_vaddr,
98 dma_handle: gdev->ddr_paddr);
99 }
100 if (gdev->sram_vaddr)
101 gen_pool_free(pool: gdev->sram_pool,
102 addr: gdev->sram_vaddr,
103 size: sram_pool_sz);
104 clk_disable(clk: 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, size: sizeof(struct uio_pruss_dev), GFP_KERNEL);
117 if (!gdev)
118 return -ENOMEM;
119
120 gdev->info = devm_kcalloc(dev, MAX_PRUSS_EVT, size: 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, id: "pruss");
126 if (IS_ERR(ptr: gdev->pruss_clk)) {
127 dev_err(dev, "Failed to get clock\n");
128 return PTR_ERR(ptr: gdev->pruss_clk);
129 }
130
131 ret = clk_enable(clk: 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(pool: gdev->sram_pool,
154 size: sram_pool_sz, dma: &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, size: extram_pool_sz,
163 dma_handle: &(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(res: regs_prussio);
171 gdev->prussio_vaddr = ioremap(offset: regs_prussio->start, size: 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(res: 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, fmt: "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, data: gdev);
212 return 0;
213
214err_unloop:
215 for (i = 0, p = gdev->info; i < cnt; i++, p++) {
216 uio_unregister_device(info: p);
217 }
218err_unmap:
219 iounmap(addr: gdev->prussio_vaddr);
220err_free_ddr_vaddr:
221 dma_free_coherent(dev, size: extram_pool_sz, cpu_addr: gdev->ddr_vaddr,
222 dma_handle: gdev->ddr_paddr);
223err_free_sram:
224 if (pdata->sram_pool)
225 gen_pool_free(pool: gdev->sram_pool, addr: gdev->sram_vaddr, size: sram_pool_sz);
226err_clk_disable:
227 clk_disable(clk: 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(pdev: dev);
235
236 pruss_cleanup(dev: &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

source code of linux/drivers/uio/uio_pruss.c