1/*
2 * ppi.c Analog Devices Parallel Peripheral Interface driver
3 *
4 * Copyright (c) 2011 Analog Devices Inc.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
18 */
19
20#include <linux/slab.h>
21
22#include <asm/bfin_ppi.h>
23#include <asm/blackfin.h>
24#include <asm/cacheflush.h>
25#include <asm/dma.h>
26#include <asm/portmux.h>
27
28#include <media/blackfin/ppi.h>
29
30static int ppi_attach_irq(struct ppi_if *ppi, irq_handler_t handler);
31static void ppi_detach_irq(struct ppi_if *ppi);
32static int ppi_start(struct ppi_if *ppi);
33static int ppi_stop(struct ppi_if *ppi);
34static int ppi_set_params(struct ppi_if *ppi, struct ppi_params *params);
35static void ppi_update_addr(struct ppi_if *ppi, unsigned long addr);
36
37static const struct ppi_ops ppi_ops = {
38	.attach_irq = ppi_attach_irq,
39	.detach_irq = ppi_detach_irq,
40	.start = ppi_start,
41	.stop = ppi_stop,
42	.set_params = ppi_set_params,
43	.update_addr = ppi_update_addr,
44};
45
46static irqreturn_t ppi_irq_err(int irq, void *dev_id)
47{
48	struct ppi_if *ppi = dev_id;
49	const struct ppi_info *info = ppi->info;
50
51	switch (info->type) {
52	case PPI_TYPE_PPI:
53	{
54		struct bfin_ppi_regs *reg = info->base;
55		unsigned short status;
56
57		/* register on bf561 is cleared when read
58		 * others are W1C
59		 */
60		status = bfin_read16(&reg->status);
61		bfin_write16(&reg->status, 0xff00);
62		break;
63	}
64	case PPI_TYPE_EPPI:
65	{
66		struct bfin_eppi_regs *reg = info->base;
67		bfin_write16(&reg->status, 0xffff);
68		break;
69	}
70	default:
71		break;
72	}
73
74	return IRQ_HANDLED;
75}
76
77static int ppi_attach_irq(struct ppi_if *ppi, irq_handler_t handler)
78{
79	const struct ppi_info *info = ppi->info;
80	int ret;
81
82	ret = request_dma(info->dma_ch, "PPI_DMA");
83
84	if (ret) {
85		pr_err("Unable to allocate DMA channel for PPI\n");
86		return ret;
87	}
88	set_dma_callback(info->dma_ch, handler, ppi);
89
90	if (ppi->err_int) {
91		ret = request_irq(info->irq_err, ppi_irq_err, 0, "PPI ERROR", ppi);
92		if (ret) {
93			pr_err("Unable to allocate IRQ for PPI\n");
94			free_dma(info->dma_ch);
95		}
96	}
97	return ret;
98}
99
100static void ppi_detach_irq(struct ppi_if *ppi)
101{
102	const struct ppi_info *info = ppi->info;
103
104	if (ppi->err_int)
105		free_irq(info->irq_err, ppi);
106	free_dma(info->dma_ch);
107}
108
109static int ppi_start(struct ppi_if *ppi)
110{
111	const struct ppi_info *info = ppi->info;
112
113	/* enable DMA */
114	enable_dma(info->dma_ch);
115
116	/* enable PPI */
117	ppi->ppi_control |= PORT_EN;
118	switch (info->type) {
119	case PPI_TYPE_PPI:
120	{
121		struct bfin_ppi_regs *reg = info->base;
122		bfin_write16(&reg->control, ppi->ppi_control);
123		break;
124	}
125	case PPI_TYPE_EPPI:
126	{
127		struct bfin_eppi_regs *reg = info->base;
128		bfin_write32(&reg->control, ppi->ppi_control);
129		break;
130	}
131	default:
132		return -EINVAL;
133	}
134
135	SSYNC();
136	return 0;
137}
138
139static int ppi_stop(struct ppi_if *ppi)
140{
141	const struct ppi_info *info = ppi->info;
142
143	/* disable PPI */
144	ppi->ppi_control &= ~PORT_EN;
145	switch (info->type) {
146	case PPI_TYPE_PPI:
147	{
148		struct bfin_ppi_regs *reg = info->base;
149		bfin_write16(&reg->control, ppi->ppi_control);
150		break;
151	}
152	case PPI_TYPE_EPPI:
153	{
154		struct bfin_eppi_regs *reg = info->base;
155		bfin_write32(&reg->control, ppi->ppi_control);
156		break;
157	}
158	default:
159		return -EINVAL;
160	}
161
162	/* disable DMA */
163	clear_dma_irqstat(info->dma_ch);
164	disable_dma(info->dma_ch);
165
166	SSYNC();
167	return 0;
168}
169
170static int ppi_set_params(struct ppi_if *ppi, struct ppi_params *params)
171{
172	const struct ppi_info *info = ppi->info;
173	int dma32 = 0;
174	int dma_config, bytes_per_line, lines_per_frame;
175
176	bytes_per_line = params->width * params->bpp / 8;
177	lines_per_frame = params->height;
178	if (params->int_mask == 0xFFFFFFFF)
179		ppi->err_int = false;
180	else
181		ppi->err_int = true;
182
183	dma_config = (DMA_FLOW_STOP | WNR | RESTART | DMA2D | DI_EN);
184	ppi->ppi_control = params->ppi_control & ~PORT_EN;
185	switch (info->type) {
186	case PPI_TYPE_PPI:
187	{
188		struct bfin_ppi_regs *reg = info->base;
189
190		if (params->ppi_control & DMA32)
191			dma32 = 1;
192
193		bfin_write16(&reg->control, ppi->ppi_control);
194		bfin_write16(&reg->count, bytes_per_line - 1);
195		bfin_write16(&reg->frame, lines_per_frame);
196		break;
197	}
198	case PPI_TYPE_EPPI:
199	{
200		struct bfin_eppi_regs *reg = info->base;
201
202		if ((params->ppi_control & PACK_EN)
203			|| (params->ppi_control & 0x38000) > DLEN_16)
204			dma32 = 1;
205
206		bfin_write32(&reg->control, ppi->ppi_control);
207		bfin_write16(&reg->line, bytes_per_line + params->blank_clocks);
208		bfin_write16(&reg->frame, lines_per_frame);
209		bfin_write16(&reg->hdelay, 0);
210		bfin_write16(&reg->vdelay, 0);
211		bfin_write16(&reg->hcount, bytes_per_line);
212		bfin_write16(&reg->vcount, lines_per_frame);
213		break;
214	}
215	default:
216		return -EINVAL;
217	}
218
219	if (dma32) {
220		dma_config |= WDSIZE_32;
221		set_dma_x_count(info->dma_ch, bytes_per_line >> 2);
222		set_dma_x_modify(info->dma_ch, 4);
223		set_dma_y_modify(info->dma_ch, 4);
224	} else {
225		dma_config |= WDSIZE_16;
226		set_dma_x_count(info->dma_ch, bytes_per_line >> 1);
227		set_dma_x_modify(info->dma_ch, 2);
228		set_dma_y_modify(info->dma_ch, 2);
229	}
230	set_dma_y_count(info->dma_ch, lines_per_frame);
231	set_dma_config(info->dma_ch, dma_config);
232
233	SSYNC();
234	return 0;
235}
236
237static void ppi_update_addr(struct ppi_if *ppi, unsigned long addr)
238{
239	set_dma_start_addr(ppi->info->dma_ch, addr);
240}
241
242struct ppi_if *ppi_create_instance(const struct ppi_info *info)
243{
244	struct ppi_if *ppi;
245
246	if (!info || !info->pin_req)
247		return NULL;
248
249	if (peripheral_request_list(info->pin_req, KBUILD_MODNAME)) {
250		pr_err("request peripheral failed\n");
251		return NULL;
252	}
253
254	ppi = kzalloc(sizeof(*ppi), GFP_KERNEL);
255	if (!ppi) {
256		peripheral_free_list(info->pin_req);
257		pr_err("unable to allocate memory for ppi handle\n");
258		return NULL;
259	}
260	ppi->ops = &ppi_ops;
261	ppi->info = info;
262
263	pr_info("ppi probe success\n");
264	return ppi;
265}
266
267void ppi_delete_instance(struct ppi_if *ppi)
268{
269	peripheral_free_list(ppi->info->pin_req);
270	kfree(ppi);
271}
272