2 * Copyright © 2013 Keith Packard <keithp@keithp.com>
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; version 2 of the License.
8 * This program is distributed in the hope that it will be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 * You should have received a copy of the GNU General Public License along
14 * with this program; if not, write to the Free Software Foundation, Inc.,
15 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
20 static uint8_t ao_spi_mutex[LPC_NUM_SPI];
22 static struct lpc_ssp * const ao_lpc_ssp[LPC_NUM_SPI] = { &lpc_ssp0, &lpc_ssp1 };
24 #define spi_loop(len, put, get) do { \
28 /* wait for the received byte to appear */ \
29 while ((lpc_ssp->sr & (1 << LPC_SSP_SR_RNE)) == 0) \
31 /* receive a byte */ \
34 /* Wait for the SSP to go idle (it already should be) */ \
35 while (lpc_ssp->sr & (1 << LPC_SSP_SR_BSY)); \
39 ao_spi_send(const void *block, uint16_t len, uint8_t id)
41 struct lpc_ssp *lpc_ssp = ao_lpc_ssp[id];
42 const uint8_t *o = block;
44 spi_loop(len, *o++, (void));
48 ao_spi_send_fixed(uint8_t value, uint16_t len, uint8_t id)
50 struct lpc_ssp *lpc_ssp = ao_lpc_ssp[id];
52 spi_loop(len, value, (void));
56 ao_spi_recv(void *block, uint16_t len, uint8_t id)
58 struct lpc_ssp *lpc_ssp = ao_lpc_ssp[id];
61 spi_loop(len, 0xff, *i++ =);
65 ao_spi_duplex(const void *out, void *in, uint16_t len, uint8_t id)
67 struct lpc_ssp *lpc_ssp = ao_lpc_ssp[id];
68 const uint8_t *o = out;
71 spi_loop(len, *o++, *i++ =);
75 ao_spi_get(uint8_t id, uint32_t speed)
77 struct lpc_ssp *lpc_ssp = ao_lpc_ssp[id];
79 ao_mutex_get(&ao_spi_mutex[id]);
81 /* Set the clock prescale */
82 lpc_ssp->cpsr = speed;
86 ao_spi_put(uint8_t id)
88 ao_mutex_put(&ao_spi_mutex[id]);
92 ao_spi_channel_init(uint8_t id)
94 struct lpc_ssp *lpc_ssp = ao_lpc_ssp[id];
97 /* Clear interrupt registers */
102 lpc_ssp->cr0 = ((LPC_SSP_CR0_DSS_8 << LPC_SSP_CR0_DSS) |
103 (LPC_SSP_CR0_FRF_SPI << LPC_SSP_CR0_FRF) |
104 (0 << LPC_SSP_CR0_CPOL) |
105 (0 << LPC_SSP_CR0_CPHA) |
106 (0 << LPC_SSP_CR0_SCR));
108 /* Enable the device */
109 lpc_ssp->cr1 = ((0 << LPC_SSP_CR1_LBM) |
110 (1 << LPC_SSP_CR1_SSE) |
111 (LPC_SSP_CR1_MS_MASTER << LPC_SSP_CR1_MS) |
112 (0 << LPC_SSP_CR1_SOD));
114 /* Drain the receive fifo */
115 for (d = 0; d < LPC_SSP_FIFOSIZE; d++)
125 lpc_ioconf.pio0_6 = ao_lpc_alternate(LPC_IOCONF_FUNC_PIO0_6_SCK0);
129 lpc_ioconf.pio0_10 = ao_lpc_alternate(LPC_IOCONF_FUNC_PIO0_10_SCK0);
133 lpc_ioconf.pio1_29 = ao_lpc_alternate(LPC_IOCONF_FUNC_PIO1_29_SCK0);
137 #error "No pin specified for SCK0"
139 lpc_ioconf.pio0_8 = ao_lpc_alternate(LPC_IOCONF_FUNC_MISO0);
140 lpc_ioconf.pio0_9 = ao_lpc_alternate(LPC_IOCONF_FUNC_MOSI0);
142 /* Enable the device */
143 lpc_scb.sysahbclkctrl |= (1 << LPC_SCB_SYSAHBCLKCTRL_SSP0);
145 /* Turn on the clock */
146 lpc_scb.ssp0clkdiv = 1;
148 /* Reset the device */
149 lpc_scb.presetctrl &= ~(1 << LPC_SCB_PRESETCTRL_SSP0_RST_N);
150 lpc_scb.presetctrl |= (1 << LPC_SCB_PRESETCTRL_SSP0_RST_N);
151 ao_spi_channel_init(0);
157 lpc_ioconf.pio1_15 = ao_lpc_alternate(LPC_IOCONF_FUNC_PIO1_15_SCK1);
161 lpc_ioconf.pio1_20 = ao_lpc_alternate(LPC_IOCONF_FUNC_PIO1_20_SCK1);
165 #error "No pin specified for SCK1"
169 lpc_ioconf.pio0_22 = ao_lpc_alternate(LPC_IOCONF_FUNC_PIO0_22_MISO1);
173 lpc_ioconf.pio1_21 = ao_lpc_alternate(LPC_IOCONF_FUNC_PIO1_21_MISO1);
177 #error "No pin specified for MISO1"
181 lpc_ioconf.pio0_21 = ao_lpc_alternate(LPC_IOCONF_FUNC_PIO0_21_MOSI1);
185 lpc_ioconf.pio1_22 = ao_lpc_alternate(LPC_IOCONF_FUNC_PIO1_22_MOSI1);
189 #error "No pin specified for MOSI1"
192 /* Enable the device */
193 lpc_scb.sysahbclkctrl |= (1 << LPC_SCB_SYSAHBCLKCTRL_SSP1);
195 /* Turn on the clock */
196 lpc_scb.ssp1clkdiv = 1;
198 /* Reset the device */
199 lpc_scb.presetctrl &= ~(1 << LPC_SCB_PRESETCTRL_SSP1_RST_N);
200 lpc_scb.presetctrl |= (1 << LPC_SCB_PRESETCTRL_SSP1_RST_N);
201 ao_spi_channel_init(1);
202 #endif /* HAS_SPI_1 */