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Diffstat (limited to 'drivers/i2c/algos/i2c-algo-pca.c')
-rw-r--r--drivers/i2c/algos/i2c-algo-pca.c78
1 files changed, 36 insertions, 42 deletions
diff --git a/drivers/i2c/algos/i2c-algo-pca.c b/drivers/i2c/algos/i2c-algo-pca.c
index f892a424009b..ee86df4cff4b 100644
--- a/drivers/i2c/algos/i2c-algo-pca.c
+++ b/drivers/i2c/algos/i2c-algo-pca.c
@@ -1,22 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
/*
* i2c-algo-pca.c i2c driver algorithms for PCA9564 adapters
* Copyright (C) 2004 Arcom Control Systems
* Copyright (C) 2008 Pengutronix
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
- * MA 02110-1301 USA.
*/
#include <linux/kernel.h>
@@ -24,7 +10,6 @@
#include <linux/moduleparam.h>
#include <linux/delay.h>
#include <linux/jiffies.h>
-#include <linux/init.h>
#include <linux/errno.h>
#include <linux/i2c.h>
#include <linux/i2c-algo-pca.h>
@@ -45,7 +30,7 @@ static int i2c_debug;
#define pca_clock(adap) adap->i2c_clock
#define pca_set_con(adap, val) pca_outw(adap, I2C_PCA_CON, val)
#define pca_get_con(adap) pca_inw(adap, I2C_PCA_CON)
-#define pca_wait(adap) adap->wait_for_completion(adap->data)
+#define pca_wait(adap) adap->wait_for_completion_cb(adap->data)
static void pca_reset(struct i2c_algo_pca_data *adap)
{
@@ -56,8 +41,22 @@ static void pca_reset(struct i2c_algo_pca_data *adap)
pca_outw(adap, I2C_PCA_INDPTR, I2C_PCA_IPRESET);
pca_outw(adap, I2C_PCA_IND, 0xA5);
pca_outw(adap, I2C_PCA_IND, 0x5A);
+
+ /*
+ * After a reset we need to re-apply any configuration
+ * (calculated in pca_init) to get the bus in a working state.
+ */
+ pca_outw(adap, I2C_PCA_INDPTR, I2C_PCA_IMODE);
+ pca_outw(adap, I2C_PCA_IND, adap->bus_settings.mode);
+ pca_outw(adap, I2C_PCA_INDPTR, I2C_PCA_ISCLL);
+ pca_outw(adap, I2C_PCA_IND, adap->bus_settings.tlow);
+ pca_outw(adap, I2C_PCA_INDPTR, I2C_PCA_ISCLH);
+ pca_outw(adap, I2C_PCA_IND, adap->bus_settings.thi);
+
+ pca_set_con(adap, I2C_PCA_CON_ENSIO);
} else {
adap->reset_chip(adap->data);
+ pca_set_con(adap, I2C_PCA_CON_ENSIO | adap->bus_settings.clock_freq);
}
}
@@ -118,11 +117,8 @@ static int pca_address(struct i2c_algo_pca_data *adap,
struct i2c_msg *msg)
{
int sta = pca_get_con(adap);
- int addr;
+ int addr = i2c_8bit_addr_from_msg(msg);
- addr = ((0x7f & msg->addr) << 1);
- if (msg->flags & I2C_M_RD)
- addr |= 1;
DEB2("=== SLAVE ADDRESS %#04x+%c=%#04x\n",
msg->addr, msg->flags & I2C_M_RD ? 'R' : 'W', addr);
@@ -332,7 +328,8 @@ static int pca_xfer(struct i2c_adapter *i2c_adap,
DEB2("BUS ERROR - SDA Stuck low\n");
pca_reset(adap);
goto out;
- case 0x90: /* Bus error - SCL stuck low */
+ case 0x78: /* Bus error - SCL stuck low (PCA9665) */
+ case 0x90: /* Bus error - SCL stuck low (PCA9564) */
DEB2("BUS ERROR - SCL Stuck low\n");
pca_reset(adap);
goto out;
@@ -364,8 +361,8 @@ static u32 pca_func(struct i2c_adapter *adap)
}
static const struct i2c_algorithm pca_algo = {
- .master_xfer = pca_xfer,
- .functionality = pca_func,
+ .xfer = pca_xfer,
+ .functionality = pca_func,
};
static unsigned int pca_probe_chip(struct i2c_adapter *adap)
@@ -440,13 +437,14 @@ static int pca_init(struct i2c_adapter *adap)
" Use the nominal frequency.\n", adap->name);
}
- pca_reset(pca_data);
-
clock = pca_clock(pca_data);
printk(KERN_INFO "%s: Clock frequency is %dkHz\n",
adap->name, freqs[clock]);
- pca_set_con(pca_data, I2C_PCA_CON_ENSIO | clock);
+ /* Store settings as these will be needed when the PCA chip is reset */
+ pca_data->bus_settings.clock_freq = clock;
+
+ pca_reset(pca_data);
} else {
int clock;
int mode;
@@ -477,17 +475,17 @@ static int pca_init(struct i2c_adapter *adap)
/* To avoid integer overflow, use clock/100 for calculations */
clock = pca_clock(pca_data) / 100;
- if (pca_data->i2c_clock > 1000000) {
+ if (pca_data->i2c_clock > I2C_MAX_FAST_MODE_PLUS_FREQ) {
mode = I2C_PCA_MODE_TURBO;
min_tlow = 14;
min_thi = 5;
raise_fall_time = 22; /* Raise 11e-8s, Fall 11e-8s */
- } else if (pca_data->i2c_clock > 400000) {
+ } else if (pca_data->i2c_clock > I2C_MAX_FAST_MODE_FREQ) {
mode = I2C_PCA_MODE_FASTP;
min_tlow = 17;
min_thi = 9;
raise_fall_time = 22; /* Raise 11e-8s, Fall 11e-8s */
- } else if (pca_data->i2c_clock > 100000) {
+ } else if (pca_data->i2c_clock > I2C_MAX_STANDARD_MODE_FREQ) {
mode = I2C_PCA_MODE_FAST;
min_tlow = 44;
min_thi = 20;
@@ -513,21 +511,17 @@ static int pca_init(struct i2c_adapter *adap)
thi = tlow * min_thi / min_tlow;
}
+ /* Store settings as these will be needed when the PCA chip is reset */
+ pca_data->bus_settings.mode = mode;
+ pca_data->bus_settings.tlow = tlow;
+ pca_data->bus_settings.thi = thi;
+
pca_reset(pca_data);
printk(KERN_INFO
"%s: Clock frequency is %dHz\n", adap->name, clock * 100);
-
- pca_outw(pca_data, I2C_PCA_INDPTR, I2C_PCA_IMODE);
- pca_outw(pca_data, I2C_PCA_IND, mode);
- pca_outw(pca_data, I2C_PCA_INDPTR, I2C_PCA_ISCLL);
- pca_outw(pca_data, I2C_PCA_IND, tlow);
- pca_outw(pca_data, I2C_PCA_INDPTR, I2C_PCA_ISCLH);
- pca_outw(pca_data, I2C_PCA_IND, thi);
-
- pca_set_con(pca_data, I2C_PCA_CON_ENSIO);
}
- udelay(500); /* 500 us for oscilator to stabilise */
+ udelay(500); /* 500 us for oscillator to stabilise */
return 0;
}
@@ -559,8 +553,8 @@ int i2c_pca_add_numbered_bus(struct i2c_adapter *adap)
}
EXPORT_SYMBOL(i2c_pca_add_numbered_bus);
-MODULE_AUTHOR("Ian Campbell <icampbell@arcom.com>, "
- "Wolfram Sang <w.sang@pengutronix.de>");
+MODULE_AUTHOR("Ian Campbell <icampbell@arcom.com>");
+MODULE_AUTHOR("Wolfram Sang <kernel@pengutronix.de>");
MODULE_DESCRIPTION("I2C-Bus PCA9564/PCA9665 algorithm");
MODULE_LICENSE("GPL");
generated by cgit (git 2.34.1) at 2025-12-21 23:48:01 +0000