This patch adds support for the PCA9665 I2C controller, originally tested and
posted by Marco Aurelio da Costa. As he did not resubmit the patch after the
final review five months ago, I picked it up, made it apply to latest linus-git
and removed the minor coding-style issues.
Signed-off-by: Wolfram Sang <w.sang@xxxxxxxxxxxxxx>
---
It still works with my PCA9564, so it surely didn't break anything.
Marco, if you are still around, it would be nice to get a signed-off from you!
(I didn't change any code except adding two "\n" and one " " to debug strings)
Jean, Ben, do you think we can handle it this way? I'd like to see this
included before the last known working state gets too far off from mainline.
drivers/i2c/algos/i2c-algo-pca.c | 180 +++++++++++++++++++++++++++++++---
drivers/i2c/busses/Kconfig | 8 -
drivers/i2c/busses/i2c-pca-isa.c | 14 +-
drivers/i2c/busses/i2c-pca-platform.c | 9 -
include/linux/i2c-algo-pca.h | 33 +++++-
5 files changed, 216 insertions(+), 28 deletions(-)
Index: drivers/i2c/algos/i2c-algo-pca.c
===================================================================
--- drivers/i2c/algos/i2c-algo-pca.c.orig
+++ drivers/i2c/algos/i2c-algo-pca.c
@@ -46,6 +46,14 @@ static int i2c_debug;
#define pca_wait(adap) adap->wait_for_completion(adap->data)
#define pca_reset(adap) adap->reset_chip(adap->data)
+static void pca9665_reset(void *pd)
+{
+ struct i2c_algo_pca_data *adap = pd;
+ pca_outw(adap, I2C_PCA_INDPTR, I2C_PCA_IPRESET);
+ pca_outw(adap, I2C_PCA_IND, 0xA5);
+ pca_outw(adap, I2C_PCA_IND, 0x5A);
+}
+
/*
* Generate a start condition on the i2c bus.
*
@@ -333,27 +341,171 @@ static const struct i2c_algorithm pca_al
.functionality = pca_func,
};
-static int pca_init(struct i2c_adapter *adap)
+static unsigned int pca_probe_chip(struct i2c_adapter *adap)
{
- static int freqs[] = {330,288,217,146,88,59,44,36};
- int clock;
struct i2c_algo_pca_data *pca_data = adap->algo_data;
-
- if (pca_data->i2c_clock > 7) {
- printk(KERN_WARNING "%s: Invalid I2C clock speed selected. Trying default.\n",
- adap->name);
- pca_data->i2c_clock = I2C_PCA_CON_59kHz;
+ /* The trick here is to check if there is an indirect register
+ * available. If there is one, we will read the value we first
+ * wrote on I2C_PCA_IADR. Otherwise, we will read the last value
+ * we wrote on I2C_PCA_ADR
+ */
+ pca_outw(pca_data, I2C_PCA_INDPTR, I2C_PCA_IADR);
+ pca_outw(pca_data, I2C_PCA_IND, 0xAA);
+ pca_outw(pca_data, I2C_PCA_INDPTR, I2C_PCA_ITO);
+ pca_outw(pca_data, I2C_PCA_IND, 0x00);
+ pca_outw(pca_data, I2C_PCA_INDPTR, I2C_PCA_IADR);
+ if (pca_inw(pca_data, I2C_PCA_IND) == 0xAA) {
+ printk(KERN_INFO "%s: PCA9665 detected.\n", adap->name);
+ return I2C_PCA_CHIP_9665;
+ } else {
+ printk(KERN_INFO "%s: PCA9564 detected.\n", adap->name);
+ return I2C_PCA_CHIP_9564;
}
+}
+
+static int pca_init(struct i2c_adapter *adap)
+{
+ struct i2c_algo_pca_data *pca_data = adap->algo_data;
adap->algo = &pca_algo;
- pca_reset(pca_data);
+ if (pca_probe_chip(adap) == I2C_PCA_CHIP_9564) {
+ static int freqs[] = {330, 288, 217, 146, 88, 59, 44, 36};
+ int clock;
+
+ if (pca_data->i2c_clock > 7) {
+ switch (pca_data->i2c_clock) {
+ case 330000:
+ pca_data->i2c_clock = I2C_PCA_CON_330kHz;
+ break;
+ case 288000:
+ pca_data->i2c_clock = I2C_PCA_CON_288kHz;
+ break;
+ case 217000:
+ pca_data->i2c_clock = I2C_PCA_CON_217kHz;
+ break;
+ case 146000:
+ pca_data->i2c_clock = I2C_PCA_CON_146kHz;
+ break;
+ case 88000:
+ pca_data->i2c_clock = I2C_PCA_CON_88kHz;
+ break;
+ case 59000:
+ pca_data->i2c_clock = I2C_PCA_CON_59kHz;
+ break;
+ case 44000:
+ pca_data->i2c_clock = I2C_PCA_CON_44kHz;
+ break;
+ case 36000:
+ pca_data->i2c_clock = I2C_PCA_CON_36kHz;
+ break;
+ default:
+ printk(KERN_WARNING
+ "%s: Invalid I2C clock speed selected."
+ " Using default 59kHz.\n", adap->name);
+ pca_data->i2c_clock = I2C_PCA_CON_59kHz;
+ }
+ } else {
+ printk(KERN_WARNING "%s: "
+ "Choosing the clock frequency based on "
+ "index is deprecated."
+ " 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);
+ } else {
+ int clock;
+ int mode;
+ int tlow, thi;
+ /* Values can be found on PCA9665 datasheet section 7.3.2.6 */
+ int min_tlow, min_thi;
+ /* These values are the maximum raise and fall values allowed
+ * by the I2C operation mode (Standard, Fast or Fast+)
+ * They are used (added) below to calculate the clock dividers
+ * of PCA9665. Note that they are slightly different of the
+ * real maximum, to allow the change on mode exactly on the
+ * maximum clock rate for each mode
+ */
+ int raise_fall_time;
+
+ struct i2c_algo_pca_data *pca_data = adap->algo_data;
+
+ /* Ignore the reset function from the module,
+ * we can use the parallel bus reset
+ */
+ pca_data->reset_chip = pca9665_reset;
+
+ if (pca_data->i2c_clock > 1265800) {
+ printk(KERN_WARNING "%s: I2C clock speed too high."
+ " Using 1265.8kHz.\n", adap->name);
+ pca_data->i2c_clock = 1265800;
+ }
+
+ if (pca_data->i2c_clock < 60300) {
+ printk(KERN_WARNING "%s: I2C clock speed too low."
+ " Using 60.3kHz.\n", adap->name);
+ pca_data->i2c_clock = 60300;
+ }
- clock = pca_clock(pca_data);
- printk(KERN_INFO "%s: Clock frequency is %dkHz\n", adap->name,
- freqs[clock]);
+ /* To avoid integer overflow, use clock/100 for calculations */
+ clock = pca_clock(pca_data) / 100;
- pca_set_con(pca_data, I2C_PCA_CON_ENSIO | clock);
+ if (pca_data->i2c_clock > 10000) {
+ 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 > 4000) {
+ 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 > 1000) {
+ mode = I2C_PCA_MODE_FAST;
+ min_tlow = 44;
+ min_thi = 20;
+ raise_fall_time = 58; /* Raise 29e-8s, Fall 29e-8s */
+ } else {
+ mode = I2C_PCA_MODE_STD;
+ min_tlow = 157;
+ min_thi = 134;
+ raise_fall_time = 127; /* Raise 29e-8s, Fall 98e-8s */
+ }
+
+ /* The minimum clock that respects the thi/tlow = 134/157 is
+ * 64800 Hz. Below that, we have to fix the tlow to 255 and
+ * calculate the thi factor.
+ */
+ if (clock < 648) {
+ tlow = 255;
+ thi = 1000000 - clock * raise_fall_time;
+ thi /= (I2C_PCA_OSC_PER * clock) - tlow;
+ } else {
+ tlow = (1000000 - clock * raise_fall_time) * min_tlow;
+ tlow /= I2C_PCA_OSC_PER * clock * (min_thi + min_tlow);
+ thi = tlow * min_thi / min_tlow;
+ }
+
+ 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 */
return 0;
@@ -388,7 +540,7 @@ EXPORT_SYMBOL(i2c_pca_add_numbered_bus);
MODULE_AUTHOR("Ian Campbell <icampbell@xxxxxxxxx>, "
"Wolfram Sang <w.sang@xxxxxxxxxxxxxx>");
-MODULE_DESCRIPTION("I2C-Bus PCA9564 algorithm");
+MODULE_DESCRIPTION("I2C-Bus PCA9564/PCA9665 algorithm");
MODULE_LICENSE("GPL");
module_param(i2c_debug, int, 0);
Index: drivers/i2c/busses/i2c-pca-isa.c
===================================================================
--- drivers/i2c/busses/i2c-pca-isa.c.orig
+++ drivers/i2c/busses/i2c-pca-isa.c
@@ -41,7 +41,7 @@ static int irq = -1;
/* Data sheet recommends 59kHz for 100kHz operation due to variation
* in the actual clock rate */
-static int clock = I2C_PCA_CON_59kHz;
+static int clock = 59000;
static wait_queue_head_t pca_wait;
@@ -103,7 +103,7 @@ static struct i2c_adapter pca_isa_ops =
.owner = THIS_MODULE,
.id = I2C_HW_A_ISA,
.algo_data = &pca_isa_data,
- .name = "PCA9564 ISA Adapter",
+ .name = "PCA9564/PCA9665 ISA Adapter",
.timeout = 100,
};
@@ -196,7 +196,7 @@ static void __exit pca_isa_exit(void)
}
MODULE_AUTHOR("Ian Campbell <icampbell@xxxxxxxxx>");
-MODULE_DESCRIPTION("ISA base PCA9564 driver");
+MODULE_DESCRIPTION("ISA base PCA9564/PCA9665 driver");
MODULE_LICENSE("GPL");
module_param(base, ulong, 0);
@@ -205,7 +205,13 @@ MODULE_PARM_DESC(base, "I/O base address
module_param(irq, int, 0);
MODULE_PARM_DESC(irq, "IRQ");
module_param(clock, int, 0);
-MODULE_PARM_DESC(clock, "Clock rate as described in table 1 of PCA9564 datasheet");
+MODULE_PARM_DESC(clock, "Clock rate in hertz.\n\t\t"
+ "For PCA9564: 330000,288000,217000,146000,"
+ "88000,59000,44000,36000\n"
+ "\t\tFor PCA9665:\tStandard: 60300 - 100099\n"
+ "\t\t\t\tFast: 100100 - 400099\n"
+ "\t\t\t\tFast+: 400100 - 10000099\n"
+ "\t\t\t\tTurbo: Up to 1265800");
module_init(pca_isa_init);
module_exit(pca_isa_exit);
Index: drivers/i2c/busses/i2c-pca-platform.c
===================================================================
--- drivers/i2c/busses/i2c-pca-platform.c.orig
+++ drivers/i2c/busses/i2c-pca-platform.c
@@ -172,8 +172,9 @@ static int __devinit i2c_pca_pf_probe(st
i2c->adap.nr = pdev->id >= 0 ? pdev->id : 0;
i2c->adap.owner = THIS_MODULE;
- snprintf(i2c->adap.name, sizeof(i2c->adap.name), "PCA9564 at 0x%08lx",
- (unsigned long) res->start);
+ snprintf(i2c->adap.name, sizeof(i2c->adap.name),
+ "PCA9564/PCA9665 at 0x%08lx",
+ (unsigned long) res->start);
i2c->adap.algo_data = &i2c->algo_data;
i2c->adap.dev.parent = &pdev->dev;
i2c->adap.timeout = platform_data->timeout;
@@ -246,7 +247,7 @@ e_remap:
e_alloc:
release_mem_region(res->start, res_len(res));
e_print:
- printk(KERN_ERR "Registering PCA9564 FAILED! (%d)\n", ret);
+ printk(KERN_ERR "Registering PCA9564/PCA9665 FAILED! (%d)\n", ret);
return ret;
}
@@ -290,7 +291,7 @@ static void __exit i2c_pca_pf_exit(void)
}
MODULE_AUTHOR("Wolfram Sang <w.sang@xxxxxxxxxxxxxx>");
-MODULE_DESCRIPTION("I2C-PCA9564 platform driver");
+MODULE_DESCRIPTION("I2C-PCA9564/PCA9665 platform driver");
MODULE_LICENSE("GPL");
module_init(i2c_pca_pf_init);
Index: drivers/i2c/busses/Kconfig
===================================================================
--- drivers/i2c/busses/Kconfig.orig
+++ drivers/i2c/busses/Kconfig
@@ -617,12 +617,12 @@ config I2C_ELEKTOR
will be called i2c-elektor.
config I2C_PCA_ISA
- tristate "PCA9564 on an ISA bus"
+ tristate "PCA9564/PCA9665 on an ISA bus"
depends on ISA
select I2C_ALGOPCA
default n
help
- This driver supports ISA boards using the Philips PCA9564
+ This driver supports ISA boards using the Philips PCA9564/PCA9665
parallel bus to I2C bus controller.
This driver can also be built as a module. If so, the module
@@ -634,11 +634,11 @@ config I2C_PCA_ISA
time). If unsure, say N.
config I2C_PCA_PLATFORM
- tristate "PCA9564 as platform device"
+ tristate "PCA9564/PCA9665 as platform device"
select I2C_ALGOPCA
default n
help
- This driver supports a memory mapped Philips PCA9564
+ This driver supports a memory mapped Philips PCA9564/PCA9665
parallel bus to I2C bus controller.
This driver can also be built as a module. If so, the module
Index: include/linux/i2c-algo-pca.h
===================================================================
--- include/linux/i2c-algo-pca.h.orig
+++ include/linux/i2c-algo-pca.h
@@ -1,7 +1,14 @@
#ifndef _LINUX_I2C_ALGO_PCA_H
#define _LINUX_I2C_ALGO_PCA_H
-/* Clock speeds for the bus */
+/* Chips known to the pca algo */
+#define I2C_PCA_CHIP_9564 0x00
+#define I2C_PCA_CHIP_9665 0x01
+
+/* Internal period for PCA9665 oscilator */
+#define I2C_PCA_OSC_PER 3 /* e10-8s */
+
+/* Clock speeds for the bus for PCA9564*/
#define I2C_PCA_CON_330kHz 0x00
#define I2C_PCA_CON_288kHz 0x01
#define I2C_PCA_CON_217kHz 0x02
@@ -18,6 +25,26 @@
#define I2C_PCA_ADR 0x02 /* OWN ADR Read/Write */
#define I2C_PCA_CON 0x03 /* CONTROL Read/Write */
+/* PCA9665 registers */
+#define I2C_PCA_INDPTR 0x00 /* INDIRECT Pointer Write Only */
+#define I2C_PCA_IND 0x02 /* INDIRECT Read/Write */
+
+/* PCA9665 indirect registers */
+#define I2C_PCA_ICOUNT 0x00 /* Byte Count for buffered mode */
+#define I2C_PCA_IADR 0x01 /* OWN ADR */
+#define I2C_PCA_ISCLL 0x02 /* SCL LOW period */
+#define I2C_PCA_ISCLH 0x03 /* SCL HIGH period */
+#define I2C_PCA_ITO 0x04 /* TIMEOUT */
+#define I2C_PCA_IPRESET 0x05 /* Parallel bus reset */
+#define I2C_PCA_IMODE 0x06 /* I2C Bus mode */
+
+/* PCA9665 I2C bus mode */
+#define I2C_PCA_MODE_STD 0x00 /* Standard mode */
+#define I2C_PCA_MODE_FAST 0x01 /* Fast mode */
+#define I2C_PCA_MODE_FASTP 0x02 /* Fast Plus mode */
+#define I2C_PCA_MODE_TURBO 0x03 /* Turbo mode */
+
+
#define I2C_PCA_CON_AA 0x80 /* Assert Acknowledge */
#define I2C_PCA_CON_ENSIO 0x40 /* Enable */
#define I2C_PCA_CON_STA 0x20 /* Start */
@@ -31,7 +58,9 @@ struct i2c_algo_pca_data {
int (*read_byte) (void *data, int reg);
int (*wait_for_completion) (void *data);
void (*reset_chip) (void *data);
- /* i2c_clock values are defined in linux/i2c-algo-pca.h */
+ /* For PCA9564, use one of the predefined frequencies:
+ * 330000, 288000, 217000, 146000, 88000, 59000, 44000, 36000
+ * For PCA9665, use the frequency you want here. */
unsigned int i2c_clock;
};
--
Pengutronix e.K. | Wolfram Sang |
Industrial Linux Solutions | http://www.pengutronix.de/ |
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