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author | Srikant Patnaik | 2015-01-11 12:28:04 +0530 |
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committer | Srikant Patnaik | 2015-01-11 12:28:04 +0530 |
commit | 871480933a1c28f8a9fed4c4d34d06c439a7a422 (patch) | |
tree | 8718f573808810c2a1e8cb8fb6ac469093ca2784 /drivers/i2c/busses/i2c-ocores.c | |
parent | 9d40ac5867b9aefe0722bc1f110b965ff294d30d (diff) | |
download | FOSSEE-netbook-kernel-source-871480933a1c28f8a9fed4c4d34d06c439a7a422.tar.gz FOSSEE-netbook-kernel-source-871480933a1c28f8a9fed4c4d34d06c439a7a422.tar.bz2 FOSSEE-netbook-kernel-source-871480933a1c28f8a9fed4c4d34d06c439a7a422.zip |
Moved, renamed, and deleted files
The original directory structure was scattered and unorganized.
Changes are basically to make it look like kernel structure.
Diffstat (limited to 'drivers/i2c/busses/i2c-ocores.c')
-rw-r--r-- | drivers/i2c/busses/i2c-ocores.c | 414 |
1 files changed, 414 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-ocores.c b/drivers/i2c/busses/i2c-ocores.c new file mode 100644 index 00000000..18068dee --- /dev/null +++ b/drivers/i2c/busses/i2c-ocores.c @@ -0,0 +1,414 @@ +/* + * i2c-ocores.c: I2C bus driver for OpenCores I2C controller + * (http://www.opencores.org/projects.cgi/web/i2c/overview). + * + * Peter Korsgaard <jacmet@sunsite.dk> + * + * 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. + */ + +/* + * Device tree configuration: + * + * Required properties: + * - compatible : "opencores,i2c-ocores" + * - reg : bus address start and address range size of device + * - interrupts : interrupt number + * - regstep : size of device registers in bytes + * - clock-frequency : frequency of bus clock in Hz + * + * Example: + * + * i2c0: ocores@a0000000 { + * compatible = "opencores,i2c-ocores"; + * reg = <0xa0000000 0x8>; + * interrupts = <10>; + * + * regstep = <1>; + * clock-frequency = <20000000>; + * + * -- Devices connected on this I2C bus get + * -- defined here; address- and size-cells + * -- apply to these child devices + * + * #address-cells = <1>; + * #size-cells = <0>; + * + * dummy@60 { + * compatible = "dummy"; + * reg = <60>; + * }; + * }; + * + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/errno.h> +#include <linux/platform_device.h> +#include <linux/i2c.h> +#include <linux/interrupt.h> +#include <linux/wait.h> +#include <linux/i2c-ocores.h> +#include <linux/slab.h> +#include <linux/io.h> + +struct ocores_i2c { + void __iomem *base; + int regstep; + wait_queue_head_t wait; + struct i2c_adapter adap; + struct i2c_msg *msg; + int pos; + int nmsgs; + int state; /* see STATE_ */ + int clock_khz; +}; + +/* registers */ +#define OCI2C_PRELOW 0 +#define OCI2C_PREHIGH 1 +#define OCI2C_CONTROL 2 +#define OCI2C_DATA 3 +#define OCI2C_CMD 4 /* write only */ +#define OCI2C_STATUS 4 /* read only, same address as OCI2C_CMD */ + +#define OCI2C_CTRL_IEN 0x40 +#define OCI2C_CTRL_EN 0x80 + +#define OCI2C_CMD_START 0x91 +#define OCI2C_CMD_STOP 0x41 +#define OCI2C_CMD_READ 0x21 +#define OCI2C_CMD_WRITE 0x11 +#define OCI2C_CMD_READ_ACK 0x21 +#define OCI2C_CMD_READ_NACK 0x29 +#define OCI2C_CMD_IACK 0x01 + +#define OCI2C_STAT_IF 0x01 +#define OCI2C_STAT_TIP 0x02 +#define OCI2C_STAT_ARBLOST 0x20 +#define OCI2C_STAT_BUSY 0x40 +#define OCI2C_STAT_NACK 0x80 + +#define STATE_DONE 0 +#define STATE_START 1 +#define STATE_WRITE 2 +#define STATE_READ 3 +#define STATE_ERROR 4 + +static inline void oc_setreg(struct ocores_i2c *i2c, int reg, u8 value) +{ + iowrite8(value, i2c->base + reg * i2c->regstep); +} + +static inline u8 oc_getreg(struct ocores_i2c *i2c, int reg) +{ + return ioread8(i2c->base + reg * i2c->regstep); +} + +static void ocores_process(struct ocores_i2c *i2c) +{ + struct i2c_msg *msg = i2c->msg; + u8 stat = oc_getreg(i2c, OCI2C_STATUS); + + if ((i2c->state == STATE_DONE) || (i2c->state == STATE_ERROR)) { + /* stop has been sent */ + oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_IACK); + wake_up(&i2c->wait); + return; + } + + /* error? */ + if (stat & OCI2C_STAT_ARBLOST) { + i2c->state = STATE_ERROR; + oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_STOP); + return; + } + + if ((i2c->state == STATE_START) || (i2c->state == STATE_WRITE)) { + i2c->state = + (msg->flags & I2C_M_RD) ? STATE_READ : STATE_WRITE; + + if (stat & OCI2C_STAT_NACK) { + i2c->state = STATE_ERROR; + oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_STOP); + return; + } + } else + msg->buf[i2c->pos++] = oc_getreg(i2c, OCI2C_DATA); + + /* end of msg? */ + if (i2c->pos == msg->len) { + i2c->nmsgs--; + i2c->msg++; + i2c->pos = 0; + msg = i2c->msg; + + if (i2c->nmsgs) { /* end? */ + /* send start? */ + if (!(msg->flags & I2C_M_NOSTART)) { + u8 addr = (msg->addr << 1); + + if (msg->flags & I2C_M_RD) + addr |= 1; + + i2c->state = STATE_START; + + oc_setreg(i2c, OCI2C_DATA, addr); + oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_START); + return; + } else + i2c->state = (msg->flags & I2C_M_RD) + ? STATE_READ : STATE_WRITE; + } else { + i2c->state = STATE_DONE; + oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_STOP); + return; + } + } + + if (i2c->state == STATE_READ) { + oc_setreg(i2c, OCI2C_CMD, i2c->pos == (msg->len-1) ? + OCI2C_CMD_READ_NACK : OCI2C_CMD_READ_ACK); + } else { + oc_setreg(i2c, OCI2C_DATA, msg->buf[i2c->pos++]); + oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_WRITE); + } +} + +static irqreturn_t ocores_isr(int irq, void *dev_id) +{ + struct ocores_i2c *i2c = dev_id; + + ocores_process(i2c); + + return IRQ_HANDLED; +} + +static int ocores_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) +{ + struct ocores_i2c *i2c = i2c_get_adapdata(adap); + + i2c->msg = msgs; + i2c->pos = 0; + i2c->nmsgs = num; + i2c->state = STATE_START; + + oc_setreg(i2c, OCI2C_DATA, + (i2c->msg->addr << 1) | + ((i2c->msg->flags & I2C_M_RD) ? 1:0)); + + oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_START); + + if (wait_event_timeout(i2c->wait, (i2c->state == STATE_ERROR) || + (i2c->state == STATE_DONE), HZ)) + return (i2c->state == STATE_DONE) ? num : -EIO; + else + return -ETIMEDOUT; +} + +static void ocores_init(struct ocores_i2c *i2c) +{ + int prescale; + u8 ctrl = oc_getreg(i2c, OCI2C_CONTROL); + + /* make sure the device is disabled */ + oc_setreg(i2c, OCI2C_CONTROL, ctrl & ~(OCI2C_CTRL_EN|OCI2C_CTRL_IEN)); + + prescale = (i2c->clock_khz / (5*100)) - 1; + oc_setreg(i2c, OCI2C_PRELOW, prescale & 0xff); + oc_setreg(i2c, OCI2C_PREHIGH, prescale >> 8); + + /* Init the device */ + oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_IACK); + oc_setreg(i2c, OCI2C_CONTROL, ctrl | OCI2C_CTRL_IEN | OCI2C_CTRL_EN); +} + + +static u32 ocores_func(struct i2c_adapter *adap) +{ + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; +} + +static const struct i2c_algorithm ocores_algorithm = { + .master_xfer = ocores_xfer, + .functionality = ocores_func, +}; + +static struct i2c_adapter ocores_adapter = { + .owner = THIS_MODULE, + .name = "i2c-ocores", + .class = I2C_CLASS_HWMON | I2C_CLASS_SPD, + .algo = &ocores_algorithm, +}; + +#ifdef CONFIG_OF +static int ocores_i2c_of_probe(struct platform_device* pdev, + struct ocores_i2c* i2c) +{ + const __be32* val; + + val = of_get_property(pdev->dev.of_node, "regstep", NULL); + if (!val) { + dev_err(&pdev->dev, "Missing required parameter 'regstep'"); + return -ENODEV; + } + i2c->regstep = be32_to_cpup(val); + + val = of_get_property(pdev->dev.of_node, "clock-frequency", NULL); + if (!val) { + dev_err(&pdev->dev, + "Missing required parameter 'clock-frequency'"); + return -ENODEV; + } + i2c->clock_khz = be32_to_cpup(val) / 1000; + + return 0; +} +#else +#define ocores_i2c_of_probe(pdev,i2c) -ENODEV +#endif + +static int __devinit ocores_i2c_probe(struct platform_device *pdev) +{ + struct ocores_i2c *i2c; + struct ocores_i2c_platform_data *pdata; + struct resource *res, *res2; + int ret; + int i; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) + return -ENODEV; + + res2 = platform_get_resource(pdev, IORESOURCE_IRQ, 0); + if (!res2) + return -ENODEV; + + i2c = devm_kzalloc(&pdev->dev, sizeof(*i2c), GFP_KERNEL); + if (!i2c) + return -ENOMEM; + + if (!devm_request_mem_region(&pdev->dev, res->start, + resource_size(res), pdev->name)) { + dev_err(&pdev->dev, "Memory region busy\n"); + return -EBUSY; + } + + i2c->base = devm_ioremap_nocache(&pdev->dev, res->start, + resource_size(res)); + if (!i2c->base) { + dev_err(&pdev->dev, "Unable to map registers\n"); + return -EIO; + } + + pdata = pdev->dev.platform_data; + if (pdata) { + i2c->regstep = pdata->regstep; + i2c->clock_khz = pdata->clock_khz; + } else { + ret = ocores_i2c_of_probe(pdev, i2c); + if (ret) + return ret; + } + + ocores_init(i2c); + + init_waitqueue_head(&i2c->wait); + ret = devm_request_irq(&pdev->dev, res2->start, ocores_isr, 0, + pdev->name, i2c); + if (ret) { + dev_err(&pdev->dev, "Cannot claim IRQ\n"); + return ret; + } + + /* hook up driver to tree */ + platform_set_drvdata(pdev, i2c); + i2c->adap = ocores_adapter; + i2c_set_adapdata(&i2c->adap, i2c); + i2c->adap.dev.parent = &pdev->dev; + i2c->adap.dev.of_node = pdev->dev.of_node; + + /* add i2c adapter to i2c tree */ + ret = i2c_add_adapter(&i2c->adap); + if (ret) { + dev_err(&pdev->dev, "Failed to add adapter\n"); + return ret; + } + + /* add in known devices to the bus */ + if (pdata) { + for (i = 0; i < pdata->num_devices; i++) + i2c_new_device(&i2c->adap, pdata->devices + i); + } + + return 0; +} + +static int __devexit ocores_i2c_remove(struct platform_device* pdev) +{ + struct ocores_i2c *i2c = platform_get_drvdata(pdev); + + /* disable i2c logic */ + oc_setreg(i2c, OCI2C_CONTROL, oc_getreg(i2c, OCI2C_CONTROL) + & ~(OCI2C_CTRL_EN|OCI2C_CTRL_IEN)); + + /* remove adapter & data */ + i2c_del_adapter(&i2c->adap); + platform_set_drvdata(pdev, NULL); + + return 0; +} + +#ifdef CONFIG_PM +static int ocores_i2c_suspend(struct platform_device *pdev, pm_message_t state) +{ + struct ocores_i2c *i2c = platform_get_drvdata(pdev); + u8 ctrl = oc_getreg(i2c, OCI2C_CONTROL); + + /* make sure the device is disabled */ + oc_setreg(i2c, OCI2C_CONTROL, ctrl & ~(OCI2C_CTRL_EN|OCI2C_CTRL_IEN)); + + return 0; +} + +static int ocores_i2c_resume(struct platform_device *pdev) +{ + struct ocores_i2c *i2c = platform_get_drvdata(pdev); + + ocores_init(i2c); + + return 0; +} +#else +#define ocores_i2c_suspend NULL +#define ocores_i2c_resume NULL +#endif + +static struct of_device_id ocores_i2c_match[] = { + { .compatible = "opencores,i2c-ocores", }, + {}, +}; +MODULE_DEVICE_TABLE(of, ocores_i2c_match); + +static struct platform_driver ocores_i2c_driver = { + .probe = ocores_i2c_probe, + .remove = __devexit_p(ocores_i2c_remove), + .suspend = ocores_i2c_suspend, + .resume = ocores_i2c_resume, + .driver = { + .owner = THIS_MODULE, + .name = "ocores-i2c", + .of_match_table = ocores_i2c_match, + }, +}; + +module_platform_driver(ocores_i2c_driver); + +MODULE_AUTHOR("Peter Korsgaard <jacmet@sunsite.dk>"); +MODULE_DESCRIPTION("OpenCores I2C bus driver"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:ocores-i2c"); |