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) \
15 void 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 } \
60 out: \
61 va_end(args); \
62 } \
63 EXPORT_SYMBOL(func);
64
65 define_fbtft_write_reg(fbtft_write_reg8_bus8, u8, u8, )
define_fbtft_write_reg(fbtft_write_reg16_bus8,__be16,u16,cpu_to_be16)66 define_fbtft_write_reg(fbtft_write_reg16_bus8, __be16, u16, cpu_to_be16)
67 define_fbtft_write_reg(fbtft_write_reg16_bus16, u16, u16, )
68
69 void 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 }
112 EXPORT_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 */
fbtft_write_vmem16_bus8(struct fbtft_par * par,size_t offset,size_t len)121 int 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 fbtft_par_dbg(DEBUG_WRITE_VMEM, par, "%s(offset=%zu, len=%zu)\n",
133 __func__, offset, len);
134
135 remain = len / 2;
136 vmem16 = (u16 *)(par->info->screen_buffer + offset);
137
138 gpiod_set_value(par->gpio.dc, 1);
139
140 /* non buffered write */
141 if (!par->txbuf.buf)
142 return par->fbtftops.write(par, vmem16, len);
143
144 /* buffered write */
145 tx_array_size = par->txbuf.len / 2;
146
147 if (par->startbyte) {
148 txbuf16 = par->txbuf.buf + 1;
149 tx_array_size -= 2;
150 *(u8 *)(par->txbuf.buf) = par->startbyte | 0x2;
151 startbyte_size = 1;
152 }
153
154 while (remain) {
155 to_copy = min(tx_array_size, remain);
156 dev_dbg(par->info->device, "to_copy=%zu, remain=%zu\n",
157 to_copy, remain - to_copy);
158
159 for (i = 0; i < to_copy; i++)
160 txbuf16[i] = cpu_to_be16(vmem16[i]);
161
162 vmem16 = vmem16 + to_copy;
163 ret = par->fbtftops.write(par, par->txbuf.buf,
164 startbyte_size + to_copy * 2);
165 if (ret < 0)
166 return ret;
167 remain -= to_copy;
168 }
169
170 return ret;
171 }
172 EXPORT_SYMBOL(fbtft_write_vmem16_bus8);
173
174 /* 16 bit pixel over 9-bit SPI bus: dc + high byte, dc + low byte */
fbtft_write_vmem16_bus9(struct fbtft_par * par,size_t offset,size_t len)175 int fbtft_write_vmem16_bus9(struct fbtft_par *par, size_t offset, size_t len)
176 {
177 u8 *vmem8;
178 u16 *txbuf16 = par->txbuf.buf;
179 size_t remain;
180 size_t to_copy;
181 size_t tx_array_size;
182 int i;
183 int ret = 0;
184
185 fbtft_par_dbg(DEBUG_WRITE_VMEM, par, "%s(offset=%zu, len=%zu)\n",
186 __func__, offset, len);
187
188 if (!par->txbuf.buf) {
189 dev_err(par->info->device, "%s: txbuf.buf is NULL\n", __func__);
190 return -1;
191 }
192
193 remain = len;
194 vmem8 = par->info->screen_buffer + offset;
195
196 tx_array_size = par->txbuf.len / 2;
197
198 while (remain) {
199 to_copy = min(tx_array_size, remain);
200 dev_dbg(par->info->device, "to_copy=%zu, remain=%zu\n",
201 to_copy, remain - to_copy);
202
203 #ifdef __LITTLE_ENDIAN
204 for (i = 0; i < to_copy; i += 2) {
205 txbuf16[i] = 0x0100 | vmem8[i + 1];
206 txbuf16[i + 1] = 0x0100 | vmem8[i];
207 }
208 #else
209 for (i = 0; i < to_copy; i++)
210 txbuf16[i] = 0x0100 | vmem8[i];
211 #endif
212 vmem8 = vmem8 + to_copy;
213 ret = par->fbtftops.write(par, par->txbuf.buf, to_copy * 2);
214 if (ret < 0)
215 return ret;
216 remain -= to_copy;
217 }
218
219 return ret;
220 }
221 EXPORT_SYMBOL(fbtft_write_vmem16_bus9);
222
fbtft_write_vmem8_bus8(struct fbtft_par * par,size_t offset,size_t len)223 int fbtft_write_vmem8_bus8(struct fbtft_par *par, size_t offset, size_t len)
224 {
225 dev_err(par->info->device, "%s: function not implemented\n", __func__);
226 return -1;
227 }
228 EXPORT_SYMBOL(fbtft_write_vmem8_bus8);
229
230 /* 16 bit pixel over 16-bit databus */
fbtft_write_vmem16_bus16(struct fbtft_par * par,size_t offset,size_t len)231 int fbtft_write_vmem16_bus16(struct fbtft_par *par, size_t offset, size_t len)
232 {
233 u16 *vmem16;
234
235 fbtft_par_dbg(DEBUG_WRITE_VMEM, par, "%s(offset=%zu, len=%zu)\n",
236 __func__, offset, len);
237
238 vmem16 = (u16 *)(par->info->screen_buffer + offset);
239
240 /* no need for buffered write with 16-bit bus */
241 return fbtft_write_buf_dc(par, vmem16, len, 1);
242 }
243 EXPORT_SYMBOL(fbtft_write_vmem16_bus16);
244