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29 * Copyright 2010 Develer S.r.l. (http://www.develer.com/)
33 * \brief Driver for the LPC23xx I2C (implementation)
35 * \author Daniele Basile <asterix@develer.com>
38 #include "cfg/cfg_i2c.h"
40 #define LOG_LEVEL I2C_LOG_LEVEL
41 #define LOG_FORMAT I2C_LOG_FORMAT
45 #include <cfg/debug.h>
46 #include <cfg/macros.h> // BV()
48 #include <cpu/detect.h>
50 #include <cpu/power.h>
52 #include <drv/timer.h>
55 #include <io/lpc23xx.h>
70 * Wait that SI bit is set.
72 * Note: this bit is set when the I2C state changes. However, entering
73 * state F8 does not set SI since there is nothing for an interrupt service
74 * routine to do in that case.
76 #define WAIT_SI(i2c) \
78 ticks_t start = timer_clock(); \
79 while( !(HWREG(i2c->hw->base + I2C_CONSET_OFF) & BV(I2CON_SI)) ) \
81 if (timer_clock() - start > ms_to_ticks(CONFIG_I2C_START_TIMEOUT)) \
83 LOG_ERR("Timeout SI assert\n"); \
84 LOG_ERR("[%08lx]\n", HWREG(i2c->hw->base + I2C_STAT_OFF)); \
91 static void i2c_hw_restart(I2c *i2c)
93 // Clear all pending flags.
94 HWREG(i2c->hw->base + I2C_CONCLR_OFF) = BV(I2CON_STAC) | BV(I2CON_SIC) | BV(I2CON_AAC);
96 // Set start and ack bit.
97 HWREG(i2c->hw->base + I2C_CONSET_OFF) = BV(I2CON_STA);
103 static void i2c_hw_stop(I2c *i2c)
105 /* Set the stop bit */
106 HWREG(i2c->hw->base + I2C_CONSET_OFF) = BV(I2CON_STO);
107 /* Clear pending flags */
108 HWREG(i2c->hw->base + I2C_CONCLR_OFF) = BV(I2CON_STAC) | BV(I2CON_SIC) | BV(I2CON_AAC);
111 static void i2c_lpc2_putc(I2c *i2c, uint8_t data)
113 HWREG(i2c->hw->base + I2C_DAT_OFF) = data;
114 HWREG(i2c->hw->base + I2C_CONCLR_OFF) = BV(I2CON_SIC);
118 uint32_t status = HWREG(i2c->hw->base + I2C_STAT_OFF);
121 /* Generate the stop if we finish to send all programmed bytes */
122 if (i2c->xfer_size == 1)
124 if (I2C_TEST_STOP(i2c->flags) == I2C_STOP)
128 if (status == I2C_STAT_DATA_NACK)
130 LOG_ERR("Data NACK\n");
131 i2c->errors |= I2C_NO_ACK;
134 else if ((status == I2C_STAT_ERROR) || (status == I2C_STAT_UNKNOW))
136 LOG_ERR("I2C error.\n");
137 i2c->errors |= I2C_ERR;
142 static uint8_t i2c_lpc2_getc(I2c *i2c)
145 * Set ack bit if we want read more byte, otherwise
148 if (i2c->xfer_size > 1)
149 HWREG(i2c->hw->base + I2C_CONSET_OFF) = BV(I2CON_AA);
151 HWREG(i2c->hw->base + I2C_CONCLR_OFF) = BV(I2CON_AAC);
153 HWREG(i2c->hw->base + I2C_CONCLR_OFF) = BV(I2CON_SIC);
157 uint32_t status = HWREG(i2c->hw->base + I2C_STAT_OFF);
158 uint8_t data = (uint8_t)HWREG(i2c->hw->base + I2C_DAT_OFF);
160 if (status == I2C_STAT_RDATA_ACK)
164 else if (status == I2C_STAT_RDATA_NACK)
167 * last byte to read generate the stop if
170 if (I2C_TEST_STOP(i2c->flags) == I2C_STOP)
175 else if ((status == I2C_STAT_ERROR) || (status == I2C_STAT_UNKNOW))
177 LOG_ERR("I2C error.\n");
178 i2c->errors |= I2C_ERR;
185 static void i2c_lpc2_start(struct I2c *i2c, uint16_t slave_addr)
187 if (I2C_TEST_START(i2c->flags) == I2C_START_W)
189 ticks_t start = timer_clock();
194 uint8_t status = HWREG(i2c->hw->base + I2C_STAT_OFF);
196 /* Start status ok, set addres and the R/W bit */
197 if ((status == I2C_STAT_SEND) || (status == I2C_STAT_RESEND))
198 HWREG(i2c->hw->base + I2C_DAT_OFF) = slave_addr & ~I2C_READBIT;
200 /* Clear the start bit and clear the SI bit */
201 HWREG(i2c->hw->base + I2C_CONCLR_OFF) = BV(I2CON_SIC) | BV(I2CON_STAC);
203 if (status == I2C_STAT_SLAW_ACK)
206 if (status == I2C_STAT_ARB_LOST)
208 LOG_ERR("Arbitration lost\n");
209 i2c->errors |= I2C_ARB_LOST;
213 if (timer_clock() - start > ms_to_ticks(CONFIG_I2C_START_TIMEOUT))
215 LOG_ERR("Timeout on I2C START\n");
216 i2c->errors |= I2C_NO_ACK;
222 else if (I2C_TEST_START(i2c->flags) == I2C_START_R)
226 uint8_t status = HWREG(i2c->hw->base + I2C_STAT_OFF);
228 /* Start status ok, set addres and the R/W bit */
229 if ((status == I2C_STAT_SEND) || (status == I2C_STAT_RESEND))
230 HWREG(i2c->hw->base + I2C_DAT_OFF) = slave_addr | I2C_READBIT;
232 /* Clear the start bit and clear the SI bit */
233 HWREG(i2c->hw->base + I2C_CONCLR_OFF) = BV(I2CON_SIC) | BV(I2CON_STAC);
237 status = HWREG(i2c->hw->base + I2C_STAT_OFF);
239 if (status == I2C_STAT_SLAR_NACK)
241 LOG_ERR("SLAR NACK:%02x\n", status);
242 i2c->errors |= I2C_NO_ACK;
246 if (status == I2C_STAT_ARB_LOST)
248 LOG_ERR("Arbitration lost\n");
249 i2c->errors |= I2C_ARB_LOST;
259 static const I2cVT i2c_lpc_vt =
261 .start = i2c_lpc2_start,
262 .getc = i2c_lpc2_getc,
263 .putc = i2c_lpc2_putc,
264 .write = i2c_genericWrite,
265 .read = i2c_genericRead,
268 static struct I2cHardware i2c_lpc2_hw[] =
271 .base = I2C0_BASE_ADDR,
272 .pconp = BV(PCONP_PCI2C0),
273 .pinsel_port = PINSEL1_OFF,
274 .pinsel = I2C0_PINSEL,
275 .pinsel_mask = I2C0_PINSEL_MASK,
276 .pclksel = PCLKSEL0_OFF,
277 .pclk_mask = I2C0_PCLK_MASK,
278 .pclk_div = I2C0_PCLK_DIV8,
281 .base = I2C1_BASE_ADDR,
282 .pconp = BV(PCONP_PCI2C1),
283 .pinsel_port = PINSEL0_OFF,
284 .pinsel = I2C1_PINSEL,
285 .pinsel_mask = I2C1_PINSEL_MASK,
286 .pclksel = PCLKSEL1_OFF,
287 .pclk_mask = I2C1_PCLK_MASK,
288 .pclk_div = I2C1_PCLK_DIV8,
291 .base = I2C2_BASE_ADDR,
292 .pconp = BV(PCONP_PCI2C2),
293 .pinsel_port = PINSEL0_OFF,
294 .pinsel = I2C2_PINSEL,
295 .pinsel_mask = I2C2_PINSEL_MASK,
296 .pclksel = PCLKSEL1_OFF,
297 .pclk_mask = I2C2_PCLK_MASK,
298 .pclk_div = I2C2_PCLK_DIV8,
303 * Initialize I2C module.
305 void i2c_hw_init(I2c *i2c, int dev, uint32_t clock)
307 i2c->hw = &i2c_lpc2_hw[dev];
308 i2c->vt = &i2c_lpc_vt;
310 /* Enable I2C clock */
311 PCONP |= i2c->hw->pconp;
313 ASSERT(clock <= 400000);
315 HWREG(i2c->hw->base + I2C_CONCLR_OFF) = BV(I2CON_I2ENC) | BV(I2CON_STAC) | BV(I2CON_SIC) | BV(I2CON_AAC);
318 * Bit Frequency = Fplk / (I2C_I2SCLH + I2C_I2SCLL)
319 * value of I2SCLH and I2SCLL must be different
321 HWREG(SCB_BASE_ADDR + i2c->hw->pclksel) &= ~i2c->hw->pclk_mask;
322 HWREG(SCB_BASE_ADDR + i2c->hw->pclksel) |= i2c->hw->pclk_div;
324 HWREG(i2c->hw->base + I2C_SCLH_OFF) = (((CPU_FREQ / 8) / clock) / 2) + 1;
325 HWREG(i2c->hw->base + I2C_SCLL_OFF) = (((CPU_FREQ / 8) / clock) / 2);
327 ASSERT(HWREG(i2c->hw->base + I2C_SCLH_OFF) > 4);
328 ASSERT(HWREG(i2c->hw->base + I2C_SCLL_OFF) > 4);
330 /* Assign pins to SCL and SDA */
331 HWREG(PINSEL_BASE_ADDR + i2c->hw->pinsel_port) &= ~i2c->hw->pinsel_mask;
332 HWREG(PINSEL_BASE_ADDR + i2c->hw->pinsel_port) |= i2c->hw->pinsel;
335 HWREG(i2c->hw->base + I2C_CONSET_OFF) = BV(I2CON_I2EN);