1/*
2 * Programmable Real-Time Unit Sub System (PRUSS) UIO driver (uio_pruss)
3 *
4 * This driver exports PRUSS host event out interrupts and PRUSS, L3 RAM,
5 * and DDR RAM to user space for applications interacting with PRUSS firmware
6 *
7 * Copyright (C) 2010-11 Texas Instruments Incorporated - http://www.ti.com/
8 *
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License as
11 * published by the Free Software Foundation version 2.
12 *
13 * This program is distributed "as is" WITHOUT ANY WARRANTY of any
14 * kind, whether express or implied; without even the implied warranty
15 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 */
18#include <linux/device.h>
19#include <linux/module.h>
20#include <linux/moduleparam.h>
21#include <linux/platform_device.h>
22#include <linux/uio_driver.h>
23#include <linux/platform_data/uio_pruss.h>
24#include <linux/io.h>
25#include <linux/clk.h>
26#include <linux/dma-mapping.h>
27#include <linux/sizes.h>
28#include <linux/slab.h>
29#include <linux/genalloc.h>
30
31#define DRV_NAME "pruss_uio"
32#define DRV_VERSION "1.0"
33
34static int sram_pool_sz = SZ_16K;
35module_param(sram_pool_sz, int, 0);
36MODULE_PARM_DESC(sram_pool_sz, "sram pool size to allocate ");
37
38static int extram_pool_sz = SZ_256K;
39module_param(extram_pool_sz, int, 0);
40MODULE_PARM_DESC(extram_pool_sz, "external ram pool size to allocate");
41
42/*
43 * Host event IRQ numbers from PRUSS - PRUSS can generate up to 8 interrupt
44 * events to AINTC of ARM host processor - which can be used for IPC b/w PRUSS
45 * firmware and user space application, async notification from PRU firmware
46 * to user space application
47 * 3 PRU_EVTOUT0
48 * 4 PRU_EVTOUT1
49 * 5 PRU_EVTOUT2
50 * 6 PRU_EVTOUT3
51 * 7 PRU_EVTOUT4
52 * 8 PRU_EVTOUT5
53 * 9 PRU_EVTOUT6
54 * 10 PRU_EVTOUT7
55*/
56#define MAX_PRUSS_EVT 8
57
58#define PINTC_HIDISR 0x0038
59#define PINTC_HIPIR 0x0900
60#define HIPIR_NOPEND 0x80000000
61#define PINTC_HIER 0x1500
62
63struct uio_pruss_dev {
64 struct uio_info *info;
65 struct clk *pruss_clk;
66 dma_addr_t sram_paddr;
67 dma_addr_t ddr_paddr;
68 void __iomem *prussio_vaddr;
69 unsigned long sram_vaddr;
70 void *ddr_vaddr;
71 unsigned int hostirq_start;
72 unsigned int pintc_base;
73 struct gen_pool *sram_pool;
74};
75
76static irqreturn_t pruss_handler(int irq, struct uio_info *info)
77{
78 struct uio_pruss_dev *gdev = info->priv;
79 int intr_bit = (irq - gdev->hostirq_start + 2);
80 int val, intr_mask = (1 << intr_bit);
81 void __iomem *base = gdev->prussio_vaddr + gdev->pintc_base;
82 void __iomem *intren_reg = base + PINTC_HIER;
83 void __iomem *intrdis_reg = base + PINTC_HIDISR;
84 void __iomem *intrstat_reg = base + PINTC_HIPIR + (intr_bit << 2);
85
86 val = ioread32(intren_reg);
87 /* Is interrupt enabled and active ? */
88 if (!(val & intr_mask) && (ioread32(intrstat_reg) & HIPIR_NOPEND))
89 return IRQ_NONE;
90 /* Disable interrupt */
91 iowrite32(intr_bit, intrdis_reg);
92 return IRQ_HANDLED;
93}
94
95static void pruss_cleanup(struct device *dev, struct uio_pruss_dev *gdev)
96{
97 int cnt;
98 struct uio_info *p = gdev->info;
99
100 for (cnt = 0; cnt < MAX_PRUSS_EVT; cnt++, p++) {
101 uio_unregister_device(p);
102 kfree(p->name);
103 }
104 iounmap(gdev->prussio_vaddr);
105 if (gdev->ddr_vaddr) {
106 dma_free_coherent(dev, extram_pool_sz, gdev->ddr_vaddr,
107 gdev->ddr_paddr);
108 }
109 if (gdev->sram_vaddr)
110 gen_pool_free(gdev->sram_pool,
111 gdev->sram_vaddr,
112 sram_pool_sz);
113 kfree(gdev->info);
114 clk_disable(gdev->pruss_clk);
115 clk_put(gdev->pruss_clk);
116 kfree(gdev);
117}
118
119static int pruss_probe(struct platform_device *pdev)
120{
121 struct uio_info *p;
122 struct uio_pruss_dev *gdev;
123 struct resource *regs_prussio;
124 struct device *dev = &pdev->dev;
125 int ret, cnt, i, len;
126 struct uio_pruss_pdata *pdata = dev_get_platdata(dev);
127
128 gdev = kzalloc(sizeof(struct uio_pruss_dev), GFP_KERNEL);
129 if (!gdev)
130 return -ENOMEM;
131
132 gdev->info = kcalloc(MAX_PRUSS_EVT, sizeof(*p), GFP_KERNEL);
133 if (!gdev->info) {
134 ret = -ENOMEM;
135 goto err_free_gdev;
136 }
137
138 /* Power on PRU in case its not done as part of boot-loader */
139 gdev->pruss_clk = clk_get(dev, "pruss");
140 if (IS_ERR(gdev->pruss_clk)) {
141 dev_err(dev, "Failed to get clock\n");
142 ret = PTR_ERR(gdev->pruss_clk);
143 goto err_free_info;
144 }
145
146 ret = clk_enable(gdev->pruss_clk);
147 if (ret) {
148 dev_err(dev, "Failed to enable clock\n");
149 goto err_clk_put;
150 }
151
152 regs_prussio = platform_get_resource(pdev, IORESOURCE_MEM, 0);
153 if (!regs_prussio) {
154 dev_err(dev, "No PRUSS I/O resource specified\n");
155 ret = -EIO;
156 goto err_clk_disable;
157 }
158
159 if (!regs_prussio->start) {
160 dev_err(dev, "Invalid memory resource\n");
161 ret = -EIO;
162 goto err_clk_disable;
163 }
164
165 if (pdata->sram_pool) {
166 gdev->sram_pool = pdata->sram_pool;
167 gdev->sram_vaddr =
168 (unsigned long)gen_pool_dma_alloc(gdev->sram_pool,
169 sram_pool_sz, &gdev->sram_paddr);
170 if (!gdev->sram_vaddr) {
171 dev_err(dev, "Could not allocate SRAM pool\n");
172 ret = -ENOMEM;
173 goto err_clk_disable;
174 }
175 }
176
177 gdev->ddr_vaddr = dma_alloc_coherent(dev, extram_pool_sz,
178 &(gdev->ddr_paddr), GFP_KERNEL | GFP_DMA);
179 if (!gdev->ddr_vaddr) {
180 dev_err(dev, "Could not allocate external memory\n");
181 ret = -ENOMEM;
182 goto err_free_sram;
183 }
184
185 len = resource_size(regs_prussio);
186 gdev->prussio_vaddr = ioremap(regs_prussio->start, len);
187 if (!gdev->prussio_vaddr) {
188 dev_err(dev, "Can't remap PRUSS I/O address range\n");
189 ret = -ENOMEM;
190 goto err_free_ddr_vaddr;
191 }
192
193 gdev->pintc_base = pdata->pintc_base;
194 gdev->hostirq_start = platform_get_irq(pdev, 0);
195
196 for (cnt = 0, p = gdev->info; cnt < MAX_PRUSS_EVT; cnt++, p++) {
197 p->mem[0].addr = regs_prussio->start;
198 p->mem[0].size = resource_size(regs_prussio);
199 p->mem[0].memtype = UIO_MEM_PHYS;
200
201 p->mem[1].addr = gdev->sram_paddr;
202 p->mem[1].size = sram_pool_sz;
203 p->mem[1].memtype = UIO_MEM_PHYS;
204
205 p->mem[2].addr = gdev->ddr_paddr;
206 p->mem[2].size = extram_pool_sz;
207 p->mem[2].memtype = UIO_MEM_PHYS;
208
209 p->name = kasprintf(GFP_KERNEL, "pruss_evt%d", cnt);
210 p->version = DRV_VERSION;
211
212 /* Register PRUSS IRQ lines */
213 p->irq = gdev->hostirq_start + cnt;
214 p->handler = pruss_handler;
215 p->priv = gdev;
216
217 ret = uio_register_device(dev, p);
218 if (ret < 0) {
219 kfree(p->name);
220 goto err_unloop;
221 }
222 }
223
224 platform_set_drvdata(pdev, gdev);
225 return 0;
226
227err_unloop:
228 for (i = 0, p = gdev->info; i < cnt; i++, p++) {
229 uio_unregister_device(p);
230 kfree(p->name);
231 }
232 iounmap(gdev->prussio_vaddr);
233err_free_ddr_vaddr:
234 dma_free_coherent(dev, extram_pool_sz, gdev->ddr_vaddr,
235 gdev->ddr_paddr);
236err_free_sram:
237 if (pdata->sram_pool)
238 gen_pool_free(gdev->sram_pool, gdev->sram_vaddr, sram_pool_sz);
239err_clk_disable:
240 clk_disable(gdev->pruss_clk);
241err_clk_put:
242 clk_put(gdev->pruss_clk);
243err_free_info:
244 kfree(gdev->info);
245err_free_gdev:
246 kfree(gdev);
247
248 return ret;
249}
250
251static int pruss_remove(struct platform_device *dev)
252{
253 struct uio_pruss_dev *gdev = platform_get_drvdata(dev);
254
255 pruss_cleanup(&dev->dev, gdev);
256 return 0;
257}
258
259static struct platform_driver pruss_driver = {
260 .probe = pruss_probe,
261 .remove = pruss_remove,
262 .driver = {
263 .name = DRV_NAME,
264 },
265};
266
267module_platform_driver(pruss_driver);
268
269MODULE_LICENSE("GPL v2");
270MODULE_VERSION(DRV_VERSION);
271MODULE_AUTHOR("Amit Chatterjee <amit.chatterjee@ti.com>");
272MODULE_AUTHOR("Pratheesh Gangadhar <pratheesh@ti.com>");
273