--- /dev/null
+/*
+ * Cavium ThunderX i2c driver.
+ *
+ * Copyright (C) 2015,2016 Cavium Inc.
+ * Authors: Fred Martin <fmartin@caviumnetworks.com>
+ * Jan Glauber <jglauber@cavium.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/acpi.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/i2c-smbus.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_irq.h>
+#include <linux/pci.h>
+
+#include "i2c-octeon-core.h"
+
+#define DRV_NAME "i2c-thunderx"
+
+#define PCI_DEVICE_ID_THUNDER_TWSI 0xa012
+
+#define SYS_FREQ_DEFAULT 700000000
+
+#define TWSI_INT_ENA_W1C 0x1028
+#define TWSI_INT_ENA_W1S 0x1030
+
+/*
+ * Enable the CORE interrupt.
+ * The interrupt will be asserted when there is non-STAT_IDLE state in the
+ * SW_TWSI_EOP_TWSI_STAT register.
+ */
+static void thunder_i2c_int_enable(struct octeon_i2c *i2c)
+{
+ octeon_i2c_writeq_flush(TWSI_INT_CORE_INT,
+ i2c->twsi_base + TWSI_INT_ENA_W1S);
+}
+
+/*
+ * Disable the CORE interrupt.
+ */
+static void thunder_i2c_int_disable(struct octeon_i2c *i2c)
+{
+ octeon_i2c_writeq_flush(TWSI_INT_CORE_INT,
+ i2c->twsi_base + TWSI_INT_ENA_W1C);
+}
+
+static void thunder_i2c_hlc_int_enable(struct octeon_i2c *i2c)
+{
+ octeon_i2c_writeq_flush(TWSI_INT_ST_INT | TWSI_INT_TS_INT,
+ i2c->twsi_base + TWSI_INT_ENA_W1S);
+}
+
+static void thunder_i2c_hlc_int_disable(struct octeon_i2c *i2c)
+{
+ octeon_i2c_writeq_flush(TWSI_INT_ST_INT | TWSI_INT_TS_INT,
+ i2c->twsi_base + TWSI_INT_ENA_W1C);
+}
+
+static u32 thunderx_i2c_functionality(struct i2c_adapter *adap)
+{
+ return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK) |
+ I2C_FUNC_SMBUS_READ_BLOCK_DATA | I2C_SMBUS_BLOCK_PROC_CALL;
+}
+
+static const struct i2c_algorithm thunderx_i2c_algo = {
+ .master_xfer = octeon_i2c_xfer,
+ .functionality = thunderx_i2c_functionality,
+};
+
+static struct i2c_adapter thunderx_i2c_ops = {
+ .owner = THIS_MODULE,
+ .name = "ThunderX adapter",
+ .algo = &thunderx_i2c_algo,
+};
+
+static void thunder_i2c_clock_enable(struct device *dev, struct octeon_i2c *i2c)
+{
+ int ret;
+
+ i2c->clk = clk_get(dev, NULL);
+ if (IS_ERR(i2c->clk)) {
+ i2c->clk = NULL;
+ goto skip;
+ }
+
+ ret = clk_prepare_enable(i2c->clk);
+ if (ret)
+ goto skip;
+ i2c->sys_freq = clk_get_rate(i2c->clk);
+
+skip:
+ if (!i2c->sys_freq)
+ i2c->sys_freq = SYS_FREQ_DEFAULT;
+}
+
+static void thunder_i2c_clock_disable(struct device *dev, struct clk *clk)
+{
+ if (!clk)
+ return;
+ clk_disable_unprepare(clk);
+ clk_put(clk);
+}
+
+static int thunder_i2c_smbus_setup_of(struct octeon_i2c *i2c,
+ struct device_node *node)
+{
+ u32 type;
+
+ if (!node)
+ return -EINVAL;
+
+ i2c->alert_data.irq = irq_of_parse_and_map(node, 0);
+ if (!i2c->alert_data.irq)
+ return -EINVAL;
+
+ type = irqd_get_trigger_type(irq_get_irq_data(i2c->alert_data.irq));
+ i2c->alert_data.alert_edge_triggered =
+ (type & IRQ_TYPE_LEVEL_MASK) ? 1 : 0;
+
+ i2c->ara = i2c_setup_smbus_alert(&i2c->adap, &i2c->alert_data);
+ if (!i2c->ara)
+ return -ENODEV;
+ return 0;
+}
+
+static int thunder_i2c_smbus_setup(struct octeon_i2c *i2c,
+ struct device_node *node)
+{
+ /* TODO: ACPI support */
+ if (!acpi_disabled)
+ return -EOPNOTSUPP;
+
+ return thunder_i2c_smbus_setup_of(i2c, node);
+}
+
+static void thunder_i2c_smbus_remove(struct octeon_i2c *i2c)
+{
+ if (i2c->ara)
+ i2c_unregister_device(i2c->ara);
+}
+
+static int thunder_i2c_probe_pci(struct pci_dev *pdev,
+ const struct pci_device_id *ent)
+{
+ struct device *dev = &pdev->dev;
+ struct octeon_i2c *i2c;
+ int ret;
+
+ i2c = devm_kzalloc(dev, sizeof(*i2c), GFP_KERNEL);
+ if (!i2c)
+ return -ENOMEM;
+
+ i2c->roff.sw_twsi = 0x1000;
+ i2c->roff.twsi_int = 0x1010;
+ i2c->roff.sw_twsi_ext = 0x1018;
+
+ i2c->dev = dev;
+ pci_set_drvdata(pdev, i2c);
+ ret = pcim_enable_device(pdev);
+ if (ret)
+ return ret;
+
+ ret = pci_request_regions(pdev, DRV_NAME);
+ if (ret)
+ return ret;
+
+ i2c->twsi_base = pcim_iomap(pdev, 0, pci_resource_len(pdev, 0));
+ if (!i2c->twsi_base)
+ return -EINVAL;
+
+ thunder_i2c_clock_enable(dev, i2c);
+ ret = device_property_read_u32(dev, "clock-frequency", &i2c->twsi_freq);
+ if (ret)
+ i2c->twsi_freq = 100000;
+
+ init_waitqueue_head(&i2c->queue);
+
+ i2c->int_enable = thunder_i2c_int_enable;
+ i2c->int_disable = thunder_i2c_int_disable;
+ i2c->hlc_int_enable = thunder_i2c_hlc_int_enable;
+ i2c->hlc_int_disable = thunder_i2c_hlc_int_disable;
+
+ ret = pci_enable_msix(pdev, &i2c->i2c_msix, 1);
+ if (ret)
+ goto error;
+
+ ret = devm_request_irq(dev, i2c->i2c_msix.vector, octeon_i2c_isr, 0,
+ DRV_NAME, i2c);
+ if (ret)
+ goto error;
+
+ ret = octeon_i2c_init_lowlevel(i2c);
+ if (ret)
+ goto error;
+
+ octeon_i2c_set_clock(i2c);
+
+ i2c->adap = thunderx_i2c_ops;
+ i2c->adap.retries = 5;
+ i2c->adap.bus_recovery_info = &octeon_i2c_recovery_info;
+ i2c->adap.dev.parent = dev;
+ i2c->adap.dev.of_node = pdev->dev.of_node;
+ snprintf(i2c->adap.name, sizeof(i2c->adap.name),
+ "Cavium ThunderX i2c adapter at %s", dev_name(dev));
+ i2c_set_adapdata(&i2c->adap, i2c);
+
+ ret = i2c_add_adapter(&i2c->adap);
+ if (ret)
+ goto error;
+
+ dev_info(i2c->dev, "Probed. Set system clock to %u\n", i2c->sys_freq);
+
+ ret = thunder_i2c_smbus_setup(i2c, pdev->dev.of_node);
+ if (ret)
+ dev_info(dev, "SMBUS alert not active on this bus\n");
+
+ return 0;
+
+error:
+ thunder_i2c_clock_disable(dev, i2c->clk);
+ return ret;
+}
+
+static void thunder_i2c_remove_pci(struct pci_dev *pdev)
+{
+ struct octeon_i2c *i2c = pci_get_drvdata(pdev);
+
+ thunder_i2c_smbus_remove(i2c);
+ thunder_i2c_clock_disable(&pdev->dev, i2c->clk);
+ i2c_del_adapter(&i2c->adap);
+}
+
+static const struct pci_device_id thunder_i2c_pci_id_table[] = {
+ { PCI_DEVICE(PCI_VENDOR_ID_CAVIUM, PCI_DEVICE_ID_THUNDER_TWSI) },
+ { 0, }
+};
+
+MODULE_DEVICE_TABLE(pci, thunder_i2c_pci_id_table);
+
+static struct pci_driver thunder_i2c_pci_driver = {
+ .name = DRV_NAME,
+ .id_table = thunder_i2c_pci_id_table,
+ .probe = thunder_i2c_probe_pci,
+ .remove = thunder_i2c_remove_pci,
+};
+
+module_pci_driver(thunder_i2c_pci_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Fred Martin <fmartin@caviumnetworks.com>");
+MODULE_DESCRIPTION("I2C-Bus adapter for Cavium ThunderX SOC");
projects / cascardo / linux.git / blobdiff