tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1// SPDX-License-Identifier: GPL-2.0
2#include <linux/export.h>
3#include <linux/errno.h>
4#include <linux/gpio/consumer.h>
5#include <linux/spi/spi.h>
6#include "fbtft.h"
7
8/*****************************************************************************
9 *
10 * void (*write_reg)(struct fbtft_par *par, int len, ...);
11 *
12 *****************************************************************************/
13
14#define define_fbtft_write_reg(func, buffer_type, data_type, modifier) \
15void func(struct fbtft_par *par, int len, ...) \
16{ \
17 va_list args; \
18 int i, ret; \
19 int offset = 0; \
20 buffer_type *buf = (buffer_type *)par->buf; \
21 \
22 if (unlikely(par->debug & DEBUG_WRITE_REGISTER)) { \
23 va_start(args, len); \
24 for (i = 0; i < len; i++) { \
25 buf[i] = modifier((data_type)va_arg(args, \
26 unsigned int)); \
27 } \
28 va_end(args); \
29 fbtft_par_dbg_hex(DEBUG_WRITE_REGISTER, par, \
30 par->info->device, buffer_type, buf, len, \
31 "%s: ", __func__); \
32 } \
33 \
34 va_start(args, len); \
35 \
36 if (par->startbyte) { \
37 *(u8 *)par->buf = par->startbyte; \
38 buf = (buffer_type *)(par->buf + 1); \
39 offset = 1; \
40 } \
41 \
42 *buf = modifier((data_type)va_arg(args, unsigned int)); \
43 ret = fbtft_write_buf_dc(par, par->buf, sizeof(data_type) + offset, \
44 0); \
45 if (ret < 0) \
46 goto out; \
47 len--; \
48 \
49 if (par->startbyte) \
50 *(u8 *)par->buf = par->startbyte | 0x2; \
51 \
52 if (len) { \
53 i = len; \
54 while (i--) \
55 *buf++ = modifier((data_type)va_arg(args, \
56 unsigned int)); \
57 fbtft_write_buf_dc(par, par->buf, \
58 len * (sizeof(data_type) + offset), 1); \
59 } \
60out: \
61 va_end(args); \
62} \
63EXPORT_SYMBOL(func);
64
65define_fbtft_write_reg(fbtft_write_reg8_bus8, u8, u8, )
66define_fbtft_write_reg(fbtft_write_reg16_bus8, __be16, u16, cpu_to_be16)
67define_fbtft_write_reg(fbtft_write_reg16_bus16, u16, u16, )
68
69void fbtft_write_reg8_bus9(struct fbtft_par *par, int len, ...)
70{
71 va_list args;
72 int i, ret;
73 int pad = 0;
74 u16 *buf = (u16 *)par->buf;
75
76 if (unlikely(par->debug & DEBUG_WRITE_REGISTER)) {
77 va_start(args, len);
78 for (i = 0; i < len; i++)
79 *(((u8 *)buf) + i) = (u8)va_arg(args, unsigned int);
80 va_end(args);
81 fbtft_par_dbg_hex(DEBUG_WRITE_REGISTER, par,
82 par->info->device, u8, buf, len, "%s: ",
83 __func__);
84 }
85 if (len <= 0)
86 return;
87
88 if (par->spi && (par->spi->bits_per_word == 8)) {
89 /* we're emulating 9-bit, pad start of buffer with no-ops
90 * (assuming here that zero is a no-op)
91 */
92 pad = (len % 4) ? 4 - (len % 4) : 0;
93 for (i = 0; i < pad; i++)
94 *buf++ = 0x000;
95 }
96
97 va_start(args, len);
98 *buf++ = (u8)va_arg(args, unsigned int);
99 i = len - 1;
100 while (i--) {
101 *buf = (u8)va_arg(args, unsigned int);
102 *buf++ |= 0x100; /* dc=1 */
103 }
104 va_end(args);
105 ret = par->fbtftops.write(par, par->buf, (len + pad) * sizeof(u16));
106 if (ret < 0) {
107 dev_err(par->info->device,
108 "write() failed and returned %d\n", ret);
109 return;
110 }
111}
112EXPORT_SYMBOL(fbtft_write_reg8_bus9);
113
114/*****************************************************************************
115 *
116 * int (*write_vmem)(struct fbtft_par *par);
117 *
118 *****************************************************************************/
119
120/* 16 bit pixel over 8-bit databus */
121int fbtft_write_vmem16_bus8(struct fbtft_par *par, size_t offset, size_t len)
122{
123 u16 *vmem16;
124 __be16 *txbuf16 = par->txbuf.buf;
125 size_t remain;
126 size_t to_copy;
127 size_t tx_array_size;
128 int i;
129 int ret = 0;
130 size_t startbyte_size = 0;
131
132 remain = len / 2;
133 vmem16 = (u16 *)(par->info->screen_buffer + offset);
134
135 gpiod_set_value(par->gpio.dc, 1);
136
137 /* non buffered write */
138 if (!par->txbuf.buf)
139 return par->fbtftops.write(par, vmem16, len);
140
141 /* buffered write */
142 tx_array_size = par->txbuf.len / 2;
143
144 if (par->startbyte) {
145 txbuf16 = par->txbuf.buf + 1;
146 tx_array_size -= 2;
147 *(u8 *)(par->txbuf.buf) = par->startbyte | 0x2;
148 startbyte_size = 1;
149 }
150
151 while (remain) {
152 to_copy = min(tx_array_size, remain);
153 dev_dbg(par->info->device, "to_copy=%zu, remain=%zu\n",
154 to_copy, remain - to_copy);
155
156 for (i = 0; i < to_copy; i++)
157 txbuf16[i] = cpu_to_be16(vmem16[i]);
158
159 vmem16 = vmem16 + to_copy;
160 ret = par->fbtftops.write(par, par->txbuf.buf,
161 startbyte_size + to_copy * 2);
162 if (ret < 0)
163 return ret;
164 remain -= to_copy;
165 }
166
167 return ret;
168}
169EXPORT_SYMBOL(fbtft_write_vmem16_bus8);
170
171/* 16 bit pixel over 9-bit SPI bus: dc + high byte, dc + low byte */
172int fbtft_write_vmem16_bus9(struct fbtft_par *par, size_t offset, size_t len)
173{
174 u8 *vmem8;
175 u16 *txbuf16 = par->txbuf.buf;
176 size_t remain;
177 size_t to_copy;
178 size_t tx_array_size;
179 int i;
180 int ret = 0;
181
182 if (!par->txbuf.buf) {
183 dev_err(par->info->device, "%s: txbuf.buf is NULL\n", __func__);
184 return -1;
185 }
186
187 remain = len;
188 vmem8 = par->info->screen_buffer + offset;
189
190 tx_array_size = par->txbuf.len / 2;
191
192 while (remain) {
193 to_copy = min(tx_array_size, remain);
194 dev_dbg(par->info->device, "to_copy=%zu, remain=%zu\n",
195 to_copy, remain - to_copy);
196
197#ifdef __LITTLE_ENDIAN
198 for (i = 0; i < to_copy; i += 2) {
199 txbuf16[i] = 0x0100 | vmem8[i + 1];
200 txbuf16[i + 1] = 0x0100 | vmem8[i];
201 }
202#else
203 for (i = 0; i < to_copy; i++)
204 txbuf16[i] = 0x0100 | vmem8[i];
205#endif
206 vmem8 = vmem8 + to_copy;
207 ret = par->fbtftops.write(par, par->txbuf.buf, to_copy * 2);
208 if (ret < 0)
209 return ret;
210 remain -= to_copy;
211 }
212
213 return ret;
214}
215EXPORT_SYMBOL(fbtft_write_vmem16_bus9);
216
217int fbtft_write_vmem8_bus8(struct fbtft_par *par, size_t offset, size_t len)
218{
219 dev_err(par->info->device, "%s: function not implemented\n", __func__);
220 return -1;
221}
222EXPORT_SYMBOL(fbtft_write_vmem8_bus8);
223
224/* 16 bit pixel over 16-bit databus */
225int fbtft_write_vmem16_bus16(struct fbtft_par *par, size_t offset, size_t len)
226{
227 u16 *vmem16;
228
229 vmem16 = (u16 *)(par->info->screen_buffer + offset);
230
231 /* no need for buffered write with 16-bit bus */
232 return fbtft_write_buf_dc(par, vmem16, len, 1);
233}
234EXPORT_SYMBOL(fbtft_write_vmem16_bus16);