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0a355aeb24
If something goes wrong (such as the SCL being stuck low) then we need to reset the PCA chip. The issue with this is that on reset we lose all config settings and the chip ends up in a disabled state which results in a lock up/high CPU usage. We need to re-apply any configuration that had previously been set and re-enable the chip. Signed-off-by: Evan Nimmo <evan.nimmo@alliedtelesis.co.nz> Reviewed-by: Chris Packham <chris.packham@alliedtelesis.co.nz> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@kernel.org>
88 lines
2.9 KiB
C
88 lines
2.9 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _LINUX_I2C_ALGO_PCA_H
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#define _LINUX_I2C_ALGO_PCA_H
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/* Chips known to the pca algo */
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#define I2C_PCA_CHIP_9564 0x00
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#define I2C_PCA_CHIP_9665 0x01
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/* Internal period for PCA9665 oscilator */
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#define I2C_PCA_OSC_PER 3 /* e10-8s */
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/* Clock speeds for the bus for PCA9564*/
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#define I2C_PCA_CON_330kHz 0x00
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#define I2C_PCA_CON_288kHz 0x01
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#define I2C_PCA_CON_217kHz 0x02
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#define I2C_PCA_CON_146kHz 0x03
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#define I2C_PCA_CON_88kHz 0x04
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#define I2C_PCA_CON_59kHz 0x05
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#define I2C_PCA_CON_44kHz 0x06
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#define I2C_PCA_CON_36kHz 0x07
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/* PCA9564 registers */
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#define I2C_PCA_STA 0x00 /* STATUS Read Only */
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#define I2C_PCA_TO 0x00 /* TIMEOUT Write Only */
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#define I2C_PCA_DAT 0x01 /* DATA Read/Write */
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#define I2C_PCA_ADR 0x02 /* OWN ADR Read/Write */
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#define I2C_PCA_CON 0x03 /* CONTROL Read/Write */
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/* PCA9665 registers */
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#define I2C_PCA_INDPTR 0x00 /* INDIRECT Pointer Write Only */
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#define I2C_PCA_IND 0x02 /* INDIRECT Read/Write */
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/* PCA9665 indirect registers */
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#define I2C_PCA_ICOUNT 0x00 /* Byte Count for buffered mode */
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#define I2C_PCA_IADR 0x01 /* OWN ADR */
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#define I2C_PCA_ISCLL 0x02 /* SCL LOW period */
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#define I2C_PCA_ISCLH 0x03 /* SCL HIGH period */
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#define I2C_PCA_ITO 0x04 /* TIMEOUT */
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#define I2C_PCA_IPRESET 0x05 /* Parallel bus reset */
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#define I2C_PCA_IMODE 0x06 /* I2C Bus mode */
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/* PCA9665 I2C bus mode */
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#define I2C_PCA_MODE_STD 0x00 /* Standard mode */
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#define I2C_PCA_MODE_FAST 0x01 /* Fast mode */
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#define I2C_PCA_MODE_FASTP 0x02 /* Fast Plus mode */
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#define I2C_PCA_MODE_TURBO 0x03 /* Turbo mode */
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#define I2C_PCA_CON_AA 0x80 /* Assert Acknowledge */
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#define I2C_PCA_CON_ENSIO 0x40 /* Enable */
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#define I2C_PCA_CON_STA 0x20 /* Start */
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#define I2C_PCA_CON_STO 0x10 /* Stop */
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#define I2C_PCA_CON_SI 0x08 /* Serial Interrupt */
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#define I2C_PCA_CON_CR 0x07 /* Clock Rate (MASK) */
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/**
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* struct pca_i2c_bus_settings - The configured PCA i2c bus settings
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* @mode: Configured i2c bus mode
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* @tlow: Configured SCL LOW period
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* @thi: Configured SCL HIGH period
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* @clock_freq: The configured clock frequency
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*/
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struct pca_i2c_bus_settings {
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int mode;
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int tlow;
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int thi;
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int clock_freq;
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};
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struct i2c_algo_pca_data {
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void *data; /* private low level data */
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void (*write_byte) (void *data, int reg, int val);
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int (*read_byte) (void *data, int reg);
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int (*wait_for_completion) (void *data);
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void (*reset_chip) (void *data);
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/* For PCA9564, use one of the predefined frequencies:
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* 330000, 288000, 217000, 146000, 88000, 59000, 44000, 36000
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* For PCA9665, use the frequency you want here. */
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unsigned int i2c_clock;
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unsigned int chip;
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struct pca_i2c_bus_settings bus_settings;
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};
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int i2c_pca_add_bus(struct i2c_adapter *);
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int i2c_pca_add_numbered_bus(struct i2c_adapter *);
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#endif /* _LINUX_I2C_ALGO_PCA_H */
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