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_put(gdev->pruss_clk);
115	kfree(gdev);
116}
117
118static int pruss_probe(struct platform_device *pdev)
119{
120	struct uio_info *p;
121	struct uio_pruss_dev *gdev;
122	struct resource *regs_prussio;
123	struct device *dev = &pdev->dev;
124	int ret = -ENODEV, cnt = 0, len;
125	struct uio_pruss_pdata *pdata = dev_get_platdata(dev);
126
127	gdev = kzalloc(sizeof(struct uio_pruss_dev), GFP_KERNEL);
128	if (!gdev)
129		return -ENOMEM;
130
131	gdev->info = kzalloc(sizeof(*p) * MAX_PRUSS_EVT, GFP_KERNEL);
132	if (!gdev->info) {
133		kfree(gdev);
134		return -ENOMEM;
135	}
136
137	/* Power on PRU in case its not done as part of boot-loader */
138	gdev->pruss_clk = clk_get(dev, "pruss");
139	if (IS_ERR(gdev->pruss_clk)) {
140		dev_err(dev, "Failed to get clock\n");
141		ret = PTR_ERR(gdev->pruss_clk);
142		kfree(gdev->info);
143		kfree(gdev);
144		return ret;
145	} else {
146		clk_enable(gdev->pruss_clk);
147	}
148
149	regs_prussio = platform_get_resource(pdev, IORESOURCE_MEM, 0);
150	if (!regs_prussio) {
151		dev_err(dev, "No PRUSS I/O resource specified\n");
152		goto out_free;
153	}
154
155	if (!regs_prussio->start) {
156		dev_err(dev, "Invalid memory resource\n");
157		goto out_free;
158	}
159
160	if (pdata->sram_pool) {
161		gdev->sram_pool = pdata->sram_pool;
162		gdev->sram_vaddr =
163			(unsigned long)gen_pool_dma_alloc(gdev->sram_pool,
164					sram_pool_sz, &gdev->sram_paddr);
165		if (!gdev->sram_vaddr) {
166			dev_err(dev, "Could not allocate SRAM pool\n");
167			goto out_free;
168		}
169	}
170
171	gdev->ddr_vaddr = dma_alloc_coherent(dev, extram_pool_sz,
172				&(gdev->ddr_paddr), GFP_KERNEL | GFP_DMA);
173	if (!gdev->ddr_vaddr) {
174		dev_err(dev, "Could not allocate external memory\n");
175		goto out_free;
176	}
177
178	len = resource_size(regs_prussio);
179	gdev->prussio_vaddr = ioremap(regs_prussio->start, len);
180	if (!gdev->prussio_vaddr) {
181		dev_err(dev, "Can't remap PRUSS I/O  address range\n");
182		goto out_free;
183	}
184
185	gdev->pintc_base = pdata->pintc_base;
186	gdev->hostirq_start = platform_get_irq(pdev, 0);
187
188	for (cnt = 0, p = gdev->info; cnt < MAX_PRUSS_EVT; cnt++, p++) {
189		p->mem[0].addr = regs_prussio->start;
190		p->mem[0].size = resource_size(regs_prussio);
191		p->mem[0].memtype = UIO_MEM_PHYS;
192
193		p->mem[1].addr = gdev->sram_paddr;
194		p->mem[1].size = sram_pool_sz;
195		p->mem[1].memtype = UIO_MEM_PHYS;
196
197		p->mem[2].addr = gdev->ddr_paddr;
198		p->mem[2].size = extram_pool_sz;
199		p->mem[2].memtype = UIO_MEM_PHYS;
200
201		p->name = kasprintf(GFP_KERNEL, "pruss_evt%d", cnt);
202		p->version = DRV_VERSION;
203
204		/* Register PRUSS IRQ lines */
205		p->irq = gdev->hostirq_start + cnt;
206		p->handler = pruss_handler;
207		p->priv = gdev;
208
209		ret = uio_register_device(dev, p);
210		if (ret < 0)
211			goto out_free;
212	}
213
214	platform_set_drvdata(pdev, gdev);
215	return 0;
216
217out_free:
218	pruss_cleanup(dev, gdev);
219	return ret;
220}
221
222static int pruss_remove(struct platform_device *dev)
223{
224	struct uio_pruss_dev *gdev = platform_get_drvdata(dev);
225
226	pruss_cleanup(&dev->dev, gdev);
227	return 0;
228}
229
230static struct platform_driver pruss_driver = {
231	.probe = pruss_probe,
232	.remove = pruss_remove,
233	.driver = {
234		   .name = DRV_NAME,
235		   },
236};
237
238module_platform_driver(pruss_driver);
239
240MODULE_LICENSE("GPL v2");
241MODULE_VERSION(DRV_VERSION);
242MODULE_AUTHOR("Amit Chatterjee <amit.chatterjee@ti.com>");
243MODULE_AUTHOR("Pratheesh Gangadhar <pratheesh@ti.com>");