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Release 4.11 drivers/i2c/busses/i2c-ocores.c

/*
 * i2c-ocores.c: I2C bus driver for OpenCores I2C controller
 * (http://www.opencores.org/projects.cgi/web/i2c/overview).
 *
 * Peter Korsgaard <jacmet@sunsite.dk>
 *
 * Support for the GRLIB port of the controller by
 * Andreas Larsson <andreas@gaisler.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/clk.h>
#include <linux/err.h>
#include <linux/kernel.h>
#include <linux/module.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>
#include <linux/log2.h>


struct ocores_i2c {
	
void __iomem *base;
	
u32 reg_shift;
	
u32 reg_io_width;
	
wait_queue_head_t wait;
	
struct i2c_adapter adap;
	
struct i2c_msg *msg;
	
int pos;
	
int nmsgs;
	
int state; /* see STATE_ */
	
struct clk *clk;
	
int ip_clock_khz;
	
int bus_clock_khz;
	
void (*setreg)(struct ocores_i2c *i2c, int reg, u8 value);
	
u8 (*getreg)(struct ocores_i2c *i2c, int reg);
};

/* 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


#define TYPE_OCORES		0

#define TYPE_GRLIB		1


static void oc_setreg_8(struct ocores_i2c *i2c, int reg, u8 value) { iowrite8(value, i2c->base + (reg << i2c->reg_shift)); }

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Ganesan Ramalingam1647.06%133.33%
Peter Korsgaard1544.12%133.33%
Andreas Larsson38.82%133.33%
Total34100.00%3100.00%


static void oc_setreg_16(struct ocores_i2c *i2c, int reg, u8 value) { iowrite16(value, i2c->base + (reg << i2c->reg_shift)); }

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Ganesan Ramalingam1852.94%150.00%
Andreas Larsson1647.06%150.00%
Total34100.00%2100.00%


static void oc_setreg_32(struct ocores_i2c *i2c, int reg, u8 value) { iowrite32(value, i2c->base + (reg << i2c->reg_shift)); }

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Andreas Larsson1647.06%125.00%
Peter Korsgaard1338.24%125.00%
Ganesan Ramalingam514.71%250.00%
Total34100.00%4100.00%


static void oc_setreg_16be(struct ocores_i2c *i2c, int reg, u8 value) { iowrite16be(value, i2c->base + (reg << i2c->reg_shift)); }

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static void oc_setreg_32be(struct ocores_i2c *i2c, int reg, u8 value) { iowrite32be(value, i2c->base + (reg << i2c->reg_shift)); }

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static inline u8 oc_getreg_8(struct ocores_i2c *i2c, int reg) { return ioread8(i2c->base + (reg << i2c->reg_shift)); }

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Ganesan Ramalingam1548.39%133.33%
Peter Korsgaard1341.94%133.33%
Andreas Larsson39.68%133.33%
Total31100.00%3100.00%


static inline u8 oc_getreg_16(struct ocores_i2c *i2c, int reg) { return ioread16(i2c->base + (reg << i2c->reg_shift)); }

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Ganesan Ramalingam1754.84%150.00%
Andreas Larsson1445.16%150.00%
Total31100.00%2100.00%


static inline u8 oc_getreg_32(struct ocores_i2c *i2c, int reg) { return ioread32(i2c->base + (reg << i2c->reg_shift)); }

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Andreas Larsson1548.39%133.33%
Peter Korsgaard1238.71%133.33%
Ganesan Ramalingam412.90%133.33%
Total31100.00%3100.00%


static inline u8 oc_getreg_16be(struct ocores_i2c *i2c, int reg) { return ioread16be(i2c->base + (reg << i2c->reg_shift)); }

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Max Filippov31100.00%1100.00%
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static inline u8 oc_getreg_32be(struct ocores_i2c *i2c, int reg) { return ioread32be(i2c->base + (reg << i2c->reg_shift)); }

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Max Filippov31100.00%1100.00%
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static inline void oc_setreg(struct ocores_i2c *i2c, int reg, u8 value) { i2c->setreg(i2c, reg, value); }

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Andreas Larsson2275.86%150.00%
Peter Korsgaard724.14%150.00%
Total29100.00%2100.00%


static inline u8 oc_getreg(struct ocores_i2c *i2c, int reg) { return i2c->getreg(i2c, reg); }

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Peter Korsgaard2080.00%133.33%
Ganesan Ramalingam312.00%133.33%
Andreas Larsson28.00%133.33%
Total25100.00%3100.00%


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 = i2c_8bit_addr_from_msg(msg); 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); } }

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Peter Korsgaard35899.17%150.00%
Wolfram Sang30.83%150.00%
Total361100.00%2100.00%


static irqreturn_t ocores_isr(int irq, void *dev_id) { struct ocores_i2c *i2c = dev_id; ocores_process(i2c); return IRQ_HANDLED; }

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Peter Korsgaard28100.00%1100.00%
Total28100.00%1100.00%


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; }

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Peter Korsgaard141100.00%1100.00%
Total141100.00%1100.00%


static int ocores_init(struct device *dev, struct ocores_i2c *i2c) { int prescale; int diff; 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->ip_clock_khz / (5 * i2c->bus_clock_khz)) - 1; prescale = clamp(prescale, 0, 0xffff); diff = i2c->ip_clock_khz / (5 * (prescale + 1)) - i2c->bus_clock_khz; if (abs(diff) > i2c->bus_clock_khz / 10) { dev_err(dev, "Unsupported clock settings: core: %d KHz, bus: %d KHz\n", i2c->ip_clock_khz, i2c->bus_clock_khz); return -EINVAL; } 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); return 0; }

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Peter Korsgaard9854.44%133.33%
Max Filippov8145.00%133.33%
Manuel Lauss10.56%133.33%
Total180100.00%3100.00%


static u32 ocores_func(struct i2c_adapter *adap) { return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; }

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Peter Korsgaard16100.00%1100.00%
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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_DEPRECATED, .algo = &ocores_algorithm, }; static const struct of_device_id ocores_i2c_match[] = { { .compatible = "opencores,i2c-ocores", .data = (void *)TYPE_OCORES, }, { .compatible = "aeroflexgaisler,i2cmst", .data = (void *)TYPE_GRLIB, }, {}, }; MODULE_DEVICE_TABLE(of, ocores_i2c_match); #ifdef CONFIG_OF /* Read and write functions for the GRLIB port of the controller. Registers are * 32-bit big endian and the PRELOW and PREHIGH registers are merged into one * register. The subsequent registers has their offset decreased accordingly. */
static u8 oc_getreg_grlib(struct ocores_i2c *i2c, int reg) { u32 rd; int rreg = reg; if (reg != OCI2C_PRELOW) rreg--; rd = ioread32be(i2c->base + (rreg << i2c->reg_shift)); if (reg == OCI2C_PREHIGH) return (u8)(rd >> 8); else return (u8)rd; }

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Andreas Larsson7098.59%150.00%
Jonas Bonn11.41%150.00%
Total71100.00%2100.00%


static void oc_setreg_grlib(struct ocores_i2c *i2c, int reg, u8 value) { u32 curr, wr; int rreg = reg; if (reg != OCI2C_PRELOW) rreg--; if (reg == OCI2C_PRELOW || reg == OCI2C_PREHIGH) { curr = ioread32be(i2c->base + (rreg << i2c->reg_shift)); if (reg == OCI2C_PRELOW) wr = (curr & 0xff00) | value; else wr = (((u32)value) << 8) | (curr & 0xff); } else { wr = value; } iowrite32be(wr, i2c->base + (rreg << i2c->reg_shift)); }

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Andreas Larsson125100.00%1100.00%
Total125100.00%1100.00%


static int ocores_i2c_of_probe(struct platform_device *pdev, struct ocores_i2c *i2c) { struct device_node *np = pdev->dev.of_node; const struct of_device_id *match; u32 val; u32 clock_frequency; bool clock_frequency_present; if (of_property_read_u32(np, "reg-shift", &i2c->reg_shift)) { /* no 'reg-shift', check for deprecated 'regstep' */ if (!of_property_read_u32(np, "regstep", &val)) { if (!is_power_of_2(val)) { dev_err(&pdev->dev, "invalid regstep %d\n", val); return -EINVAL; } i2c->reg_shift = ilog2(val); dev_warn(&pdev->dev, "regstep property deprecated, use reg-shift\n"); } } clock_frequency_present = !of_property_read_u32(np, "clock-frequency", &clock_frequency); i2c->bus_clock_khz = 100; i2c->clk = devm_clk_get(&pdev->dev, NULL); if (!IS_ERR(i2c->clk)) { int ret = clk_prepare_enable(i2c->clk); if (ret) { dev_err(&pdev->dev, "clk_prepare_enable failed: %d\n", ret); return ret; } i2c->ip_clock_khz = clk_get_rate(i2c->clk) / 1000; if (clock_frequency_present) i2c->bus_clock_khz = clock_frequency / 1000; } if (i2c->ip_clock_khz == 0) { if (of_property_read_u32(np, "opencores,ip-clock-frequency", &val)) { if (!clock_frequency_present) { dev_err(&pdev->dev, "Missing required parameter 'opencores,ip-clock-frequency'\n"); clk_disable_unprepare(i2c->clk); return -ENODEV; } i2c->ip_clock_khz = clock_frequency / 1000; dev_warn(&pdev->dev, "Deprecated usage of the 'clock-frequency' property, please update to 'opencores,ip-clock-frequency'\n"); } else { i2c->ip_clock_khz = val / 1000; if (clock_frequency_present) i2c->bus_clock_khz = clock_frequency / 1000; } } of_property_read_u32(pdev->dev.of_node, "reg-io-width", &i2c->reg_io_width); match = of_match_node(ocores_i2c_match, pdev->dev.of_node); if (match && (long)match->data == TYPE_GRLIB) { dev_dbg(&pdev->dev, "GRLIB variant of i2c-ocores\n"); i2c->setreg = oc_setreg_grlib; i2c->getreg = oc_getreg_grlib; } return 0; }

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Max Filippov15039.27%222.22%
Jonas Bonn8823.04%111.11%
Ganesan Ramalingam7118.59%222.22%
Andreas Larsson5514.40%111.11%
Wolfram Sang102.62%111.11%
Alexey Khoroshilov71.83%111.11%
Jayachandran C10.26%111.11%
Total382100.00%9100.00%

#else #define ocores_i2c_of_probe(pdev,i2c) -ENODEV #endif
static int ocores_i2c_probe(struct platform_device *pdev) { struct ocores_i2c *i2c; struct ocores_i2c_platform_data *pdata; struct resource *res; int irq; int ret; int i; irq = platform_get_irq(pdev, 0); if (irq < 0) return irq; i2c = devm_kzalloc(&pdev->dev, sizeof(*i2c), GFP_KERNEL); if (!i2c) return -ENOMEM; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); i2c->base = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(i2c->base)) return PTR_ERR(i2c->base); pdata = dev_get_platdata(&pdev->dev); if (pdata) { i2c->reg_shift = pdata->reg_shift; i2c->reg_io_width = pdata->reg_io_width; i2c->ip_clock_khz = pdata->clock_khz; i2c->bus_clock_khz = 100; } else { ret = ocores_i2c_of_probe(pdev, i2c); if (ret) return ret; } if (i2c->reg_io_width == 0) i2c->reg_io_width = 1; /* Set to default value */ if (!i2c->setreg || !i2c->getreg) { bool be = pdata ? pdata->big_endian : of_device_is_big_endian(pdev->dev.of_node); switch (i2c->reg_io_width) { case 1: i2c->setreg = oc_setreg_8; i2c->getreg = oc_getreg_8; break; case 2: i2c->setreg = be ? oc_setreg_16be : oc_setreg_16; i2c->getreg = be ? oc_getreg_16be : oc_getreg_16; break; case 4: i2c->setreg = be ? oc_setreg_32be : oc_setreg_32; i2c->getreg = be ? oc_getreg_32be : oc_getreg_32; break; default: dev_err(&pdev->dev, "Unsupported I/O width (%d)\n", i2c->reg_io_width); ret = -EINVAL; goto err_clk; } } ret = ocores_init(&pdev->dev, i2c); if (ret) goto err_clk; init_waitqueue_head(&i2c->wait); ret = devm_request_irq(&pdev->dev, irq, ocores_isr, 0, pdev->name, i2c); if (ret) { dev_err(&pdev->dev, "Cannot claim IRQ\n"); goto err_clk; } /* 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) goto err_clk; /* 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; err_clk: clk_disable_unprepare(i2c->clk); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
Peter Korsgaard18135.01%16.25%
Andreas Larsson9718.76%212.50%
Jonas Bonn6813.15%212.50%
Max Filippov5210.06%212.50%
Richard Röjfors336.38%16.25%
Alexey Khoroshilov275.22%16.25%
Ganesan Ramalingam254.84%212.50%
Julia Lawall112.13%16.25%
Thierry Reding101.93%16.25%
Manuel Lauss71.35%16.25%
Jingoo Han40.77%16.25%
Samuel Ortiz20.39%16.25%
Total517100.00%16100.00%


static int 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); if (!IS_ERR(i2c->clk)) clk_disable_unprepare(i2c->clk); return 0; }

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Peter Korsgaard5576.39%150.00%
Max Filippov1723.61%150.00%
Total72100.00%2100.00%

#ifdef CONFIG_PM_SLEEP
static int ocores_i2c_suspend(struct device *dev) { struct ocores_i2c *i2c = dev_get_drvdata(dev); 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)); if (!IS_ERR(i2c->clk)) clk_disable_unprepare(i2c->clk); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Manuel Lauss4769.12%133.33%
Max Filippov1725.00%133.33%
Rafael J. Wysocki45.88%133.33%
Total68100.00%3100.00%


static int ocores_i2c_resume(struct device *dev) { struct ocores_i2c *i2c = dev_get_drvdata(dev); if (!IS_ERR(i2c->clk)) { unsigned long rate; int ret = clk_prepare_enable(i2c->clk); if (ret) { dev_err(dev, "clk_prepare_enable failed: %d\n", ret); return ret; } rate = clk_get_rate(i2c->clk) / 1000; if (rate) i2c->ip_clock_khz = rate; } return ocores_init(dev, i2c); }

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Max Filippov5356.38%240.00%
Manuel Lauss2223.40%120.00%
Wolfram Sang1515.96%120.00%
Rafael J. Wysocki44.26%120.00%
Total94100.00%5100.00%

static SIMPLE_DEV_PM_OPS(ocores_i2c_pm, ocores_i2c_suspend, ocores_i2c_resume); #define OCORES_I2C_PM (&ocores_i2c_pm) #else #define OCORES_I2C_PM NULL #endif static struct platform_driver ocores_i2c_driver = { .probe = ocores_i2c_probe, .remove = ocores_i2c_remove, .driver = { .name = "ocores-i2c", .of_match_table = ocores_i2c_match, .pm = OCORES_I2C_PM, }, }; 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");

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Peter Korsgaard120742.10%26.25%
Andreas Larsson53018.49%39.38%
Max Filippov51217.86%39.38%
Ganesan Ramalingam1826.35%39.38%
Jonas Bonn1786.21%26.25%
Manuel Lauss883.07%13.12%
Alexey Khoroshilov341.19%13.12%
Richard Röjfors331.15%13.12%
Wolfram Sang291.01%39.38%
Rafael J. Wysocki280.98%13.12%
Thierry Reding130.45%13.12%
Julia Lawall110.38%13.12%
Axel Lin70.24%13.12%
Jingoo Han60.21%39.38%
Tejun Heo30.10%13.12%
Samuel Ortiz20.07%13.12%
Jean Delvare10.03%13.12%
Jayachandran C10.03%13.12%
H Hartley Sweeten10.03%13.12%
Grant C. Likely10.03%13.12%
Total2867100.00%32100.00%
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