i2c-algo-pca: Add PCA9665 support

Add support for the PCA9665 I2C controller.

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

5 files changed, 216 insertions, 28 deletions

diff --git a/drivers/i2c/algos/i2c-algo-pca.c b/drivers/i2c/algos/i2c-algo-pca.c
index 943d70ee5d59..a8e51bd1a4f5 100644
--- a/drivers/i2c/algos/i2c-algo-pca.c
+++ b/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_algo = {
         .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;
+                }
+
+                /* To avoid integer overflow, use clock/100 for calculations */
+                clock = pca_clock(pca_data) / 100;
+
+                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);
 
-        clock = pca_clock(pca_data);
-        printk(KERN_INFO "%s: Clock frequency is %dkHz\n", adap->name,
-               freqs[clock]);
+                printk(KERN_INFO
+                     "%s: Clock frequency is %dHz\n", adap->name, clock * 100);
 
-        pca_set_con(pca_data, I2C_PCA_CON_ENSIO | clock);
+                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@arcom.com>, "
         "Wolfram Sang <w.sang@pengutronix.de>");
-MODULE_DESCRIPTION("I2C-Bus PCA9564 algorithm");
+MODULE_DESCRIPTION("I2C-Bus PCA9564/PCA9665 algorithm");
 MODULE_LICENSE("GPL");
 
 module_param(i2c_debug, int, 0);
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 7f95905bbb9d..68650643d116 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/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
diff --git a/drivers/i2c/busses/i2c-pca-isa.c b/drivers/i2c/busses/i2c-pca-isa.c
index c420a7c0f3e4..0cc8017b3f64 100644
--- a/drivers/i2c/busses/i2c-pca-isa.c
+++ b/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_algo_pca_data pca_isa_data = {
 static struct i2c_adapter pca_isa_ops = {
         .owner          = THIS_MODULE,
         .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@arcom.com>");
-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);
diff --git a/drivers/i2c/busses/i2c-pca-platform.c b/drivers/i2c/busses/i2c-pca-platform.c
index 6bb15ad0a6b6..51d179bbddf9 100644
--- a/drivers/i2c/busses/i2c-pca-platform.c
+++ b/drivers/i2c/busses/i2c-pca-platform.c
@@ -172,8 +172,9 @@ static int __devinit i2c_pca_pf_probe(struct platform_device *pdev)
 
         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@pengutronix.de>");
-MODULE_DESCRIPTION("I2C-PCA9564 platform driver");
+MODULE_DESCRIPTION("I2C-PCA9564/PCA9665 platform driver");
 MODULE_LICENSE("GPL");
 
 module_init(i2c_pca_pf_init);
diff --git a/include/linux/i2c-algo-pca.h b/include/linux/i2c-algo-pca.h
index adcb3dc7ac26..1364d62e2fbe 100644
--- a/include/linux/i2c-algo-pca.h
+++ b/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;
 };