diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-rcar.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-rcar.c | 344 |
1 files changed, 110 insertions, 234 deletions
diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c index d2fe11da5e8..89940592367 100644 --- a/drivers/i2c/busses/i2c-rcar.c +++ b/drivers/i2c/busses/i2c-rcar.c @@ -1,7 +1,9 @@ /* - * drivers/i2c/busses/i2c-rcar.c + * Driver for the Renesas RCar I2C unit * - * Copyright (C) 2012 Renesas Solutions Corp. + * Copyright (C) 2014 Wolfram Sang <wsa@sang-engineering.com> + * + * Copyright (C) 2012-14 Renesas Solutions Corp. * Kuninori Morimoto <kuninori.morimoto.gx@renesas.com> * * This file is based on the drivers/i2c/busses/i2c-sh7760.c @@ -12,31 +14,26 @@ * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License + * the Free Software Foundation; version 2 of the License. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #include <linux/clk.h> #include <linux/delay.h> #include <linux/err.h> -#include <linux/init.h> #include <linux/interrupt.h> #include <linux/io.h> #include <linux/i2c.h> #include <linux/i2c/i2c-rcar.h> #include <linux/kernel.h> #include <linux/module.h> +#include <linux/of_device.h> #include <linux/platform_device.h> #include <linux/pm_runtime.h> #include <linux/slab.h> -#include <linux/spinlock.h> /* register offsets */ #define ICSCR 0x00 /* slave ctrl */ @@ -60,7 +57,7 @@ #define FSB (1 << 1) /* force stop bit */ #define ESG (1 << 0) /* en startbit gen */ -/* ICMSR */ +/* ICMSR (also for ICMIE) */ #define MNR (1 << 6) /* nack received */ #define MAL (1 << 5) /* arbitration lost */ #define MST (1 << 4) /* sent a stop */ @@ -69,32 +66,18 @@ #define MDR (1 << 1) #define MAT (1 << 0) /* slave addr xfer done */ -/* ICMIE */ -#define MNRE (1 << 6) /* nack irq en */ -#define MALE (1 << 5) /* arblos irq en */ -#define MSTE (1 << 4) /* stop irq en */ -#define MDEE (1 << 3) -#define MDTE (1 << 2) -#define MDRE (1 << 1) -#define MATE (1 << 0) /* address sent irq en */ +#define RCAR_BUS_PHASE_START (MDBS | MIE | ESG) +#define RCAR_BUS_PHASE_DATA (MDBS | MIE) +#define RCAR_BUS_PHASE_STOP (MDBS | MIE | FSB) -enum { - RCAR_BUS_PHASE_ADDR, - RCAR_BUS_PHASE_DATA, - RCAR_BUS_PHASE_STOP, -}; +#define RCAR_IRQ_SEND (MNR | MAL | MST | MAT | MDE) +#define RCAR_IRQ_RECV (MNR | MAL | MST | MAT | MDR) +#define RCAR_IRQ_STOP (MST) -enum { - RCAR_IRQ_CLOSE, - RCAR_IRQ_OPEN_FOR_SEND, - RCAR_IRQ_OPEN_FOR_RECV, - RCAR_IRQ_OPEN_FOR_STOP, -}; +#define RCAR_IRQ_ACK_SEND (~(MAT | MDE)) +#define RCAR_IRQ_ACK_RECV (~(MAT | MDR)) -/* - * flags - */ #define ID_LAST_MSG (1 << 0) #define ID_IOERROR (1 << 1) #define ID_DONE (1 << 2) @@ -102,23 +85,22 @@ enum { #define ID_NACK (1 << 4) enum rcar_i2c_type { - I2C_RCAR_H1, - I2C_RCAR_H2, + I2C_RCAR_GEN1, + I2C_RCAR_GEN2, }; struct rcar_i2c_priv { void __iomem *io; struct i2c_adapter adap; struct i2c_msg *msg; + struct clk *clk; - spinlock_t lock; wait_queue_head_t wait; int pos; - int irq; u32 icccr; u32 flags; - enum rcar_i2c_type devtype; + enum rcar_i2c_type devtype; }; #define rcar_i2c_priv_to_dev(p) ((p)->adap.dev.parent) @@ -129,9 +111,7 @@ struct rcar_i2c_priv { #define LOOP_TIMEOUT 1024 -/* - * basic functions - */ + static void rcar_i2c_write(struct rcar_i2c_priv *priv, int reg, u32 val) { writel(val, priv->io + reg); @@ -160,36 +140,6 @@ static void rcar_i2c_init(struct rcar_i2c_priv *priv) rcar_i2c_write(priv, ICMAR, 0); } -static void rcar_i2c_irq_mask(struct rcar_i2c_priv *priv, int open) -{ - u32 val = MNRE | MALE | MSTE | MATE; /* default */ - - switch (open) { - case RCAR_IRQ_OPEN_FOR_SEND: - val |= MDEE; /* default + send */ - break; - case RCAR_IRQ_OPEN_FOR_RECV: - val |= MDRE; /* default + read */ - break; - case RCAR_IRQ_OPEN_FOR_STOP: - val = MSTE; /* stop irq only */ - break; - case RCAR_IRQ_CLOSE: - default: - val = 0; /* all close */ - break; - } - rcar_i2c_write(priv, ICMIER, val); -} - -static void rcar_i2c_set_addr(struct rcar_i2c_priv *priv, u32 recv) -{ - rcar_i2c_write(priv, ICMAR, (priv->msg->addr << 1) | recv); -} - -/* - * bus control functions - */ static int rcar_i2c_bus_barrier(struct rcar_i2c_priv *priv) { int i; @@ -204,44 +154,21 @@ static int rcar_i2c_bus_barrier(struct rcar_i2c_priv *priv) return -EBUSY; } -static void rcar_i2c_bus_phase(struct rcar_i2c_priv *priv, int phase) -{ - switch (phase) { - case RCAR_BUS_PHASE_ADDR: - rcar_i2c_write(priv, ICMCR, MDBS | MIE | ESG); - break; - case RCAR_BUS_PHASE_DATA: - rcar_i2c_write(priv, ICMCR, MDBS | MIE); - break; - case RCAR_BUS_PHASE_STOP: - rcar_i2c_write(priv, ICMCR, MDBS | MIE | FSB); - break; - } -} - -/* - * clock function - */ static int rcar_i2c_clock_calculate(struct rcar_i2c_priv *priv, u32 bus_speed, struct device *dev) { - struct clk *clkp = clk_get(NULL, "peripheral_clk"); u32 scgd, cdf; u32 round, ick; u32 scl; u32 cdf_width; - - if (!clkp) { - dev_err(dev, "there is no peripheral_clk\n"); - return -EIO; - } + unsigned long rate; switch (priv->devtype) { - case I2C_RCAR_H1: + case I2C_RCAR_GEN1: cdf_width = 2; break; - case I2C_RCAR_H2: + case I2C_RCAR_GEN2: cdf_width = 3; break; default: @@ -264,15 +191,14 @@ static int rcar_i2c_clock_calculate(struct rcar_i2c_priv *priv, * clkp : peripheral_clk * F[] : integer up-valuation */ - for (cdf = 0; cdf < (1 << cdf_width); cdf++) { - ick = clk_get_rate(clkp) / (1 + cdf); - if (ick < 20000000) - goto ick_find; + rate = clk_get_rate(priv->clk); + cdf = rate / 20000000; + if (cdf >= 1 << cdf_width) { + dev_err(dev, "Input clock %lu too high\n", rate); + return -EIO; } - dev_err(dev, "there is no best CDF\n"); - return -EIO; + ick = rate / (cdf + 1); -ick_find: /* * it is impossible to calculate large scale * number on u32. separate it @@ -290,6 +216,12 @@ ick_find: * * Calculation result (= SCL) should be less than * bus_speed for hardware safety + * + * We could use something along the lines of + * div = ick / (bus_speed + 1) + 1; + * scgd = (div - 20 - round + 7) / 8; + * scl = ick / (20 + (scgd * 8) + round); + * (not fully verified) but that would get pretty involved */ for (scgd = 0; scgd < 0x40; scgd++) { scl = ick / (20 + (scgd * 8) + round); @@ -301,70 +233,28 @@ ick_find: scgd_find: dev_dbg(dev, "clk %d/%d(%lu), round %u, CDF:0x%x, SCGD: 0x%x\n", - scl, bus_speed, clk_get_rate(clkp), round, cdf, scgd); + scl, bus_speed, clk_get_rate(priv->clk), round, cdf, scgd); /* * keep icccr value */ - priv->icccr = (scgd << (cdf_width) | cdf); - - return 0; -} - -static void rcar_i2c_clock_start(struct rcar_i2c_priv *priv) -{ - rcar_i2c_write(priv, ICCCR, priv->icccr); -} - -/* - * status functions - */ -static u32 rcar_i2c_status_get(struct rcar_i2c_priv *priv) -{ - return rcar_i2c_read(priv, ICMSR); -} - -#define rcar_i2c_status_clear(priv) rcar_i2c_status_bit_clear(priv, 0xffffffff) -static void rcar_i2c_status_bit_clear(struct rcar_i2c_priv *priv, u32 bit) -{ - rcar_i2c_write(priv, ICMSR, ~bit); -} - -/* - * recv/send functions - */ -static int rcar_i2c_recv(struct rcar_i2c_priv *priv) -{ - rcar_i2c_set_addr(priv, 1); - rcar_i2c_status_clear(priv); - rcar_i2c_bus_phase(priv, RCAR_BUS_PHASE_ADDR); - rcar_i2c_irq_mask(priv, RCAR_IRQ_OPEN_FOR_RECV); + priv->icccr = scgd << cdf_width | cdf; return 0; } -static int rcar_i2c_send(struct rcar_i2c_priv *priv) +static int rcar_i2c_prepare_msg(struct rcar_i2c_priv *priv) { - int ret; - - /* - * It should check bus status when send case - */ - ret = rcar_i2c_bus_barrier(priv); - if (ret < 0) - return ret; + int read = !!rcar_i2c_is_recv(priv); - rcar_i2c_set_addr(priv, 0); - rcar_i2c_status_clear(priv); - rcar_i2c_bus_phase(priv, RCAR_BUS_PHASE_ADDR); - rcar_i2c_irq_mask(priv, RCAR_IRQ_OPEN_FOR_SEND); + rcar_i2c_write(priv, ICMAR, (priv->msg->addr << 1) | read); + rcar_i2c_write(priv, ICMSR, 0); + rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_START); + rcar_i2c_write(priv, ICMIER, read ? RCAR_IRQ_RECV : RCAR_IRQ_SEND); return 0; } -#define rcar_i2c_send_restart(priv) rcar_i2c_status_bit_clear(priv, (MAT | MDE)) -#define rcar_i2c_recv_restart(priv) rcar_i2c_status_bit_clear(priv, (MAT | MDR)) - /* * interrupt functions */ @@ -385,7 +275,7 @@ static int rcar_i2c_irq_send(struct rcar_i2c_priv *priv, u32 msr) * goto data phase. */ if (msr & MAT) - rcar_i2c_bus_phase(priv, RCAR_BUS_PHASE_DATA); + rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_DATA); if (priv->pos < msg->len) { /* @@ -413,7 +303,7 @@ static int rcar_i2c_irq_send(struct rcar_i2c_priv *priv, u32 msr) * prepare stop condition here. * ID_DONE will be set on STOP irq. */ - rcar_i2c_bus_phase(priv, RCAR_BUS_PHASE_STOP); + rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_STOP); else /* * If current msg is _NOT_ last msg, @@ -424,7 +314,7 @@ static int rcar_i2c_irq_send(struct rcar_i2c_priv *priv, u32 msr) return ID_DONE; } - rcar_i2c_send_restart(priv); + rcar_i2c_write(priv, ICMSR, RCAR_IRQ_ACK_SEND); return 0; } @@ -461,11 +351,11 @@ static int rcar_i2c_irq_recv(struct rcar_i2c_priv *priv, u32 msr) * otherwise, go to DATA phase. */ if (priv->pos + 1 >= msg->len) - rcar_i2c_bus_phase(priv, RCAR_BUS_PHASE_STOP); + rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_STOP); else - rcar_i2c_bus_phase(priv, RCAR_BUS_PHASE_DATA); + rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_DATA); - rcar_i2c_recv_restart(priv); + rcar_i2c_write(priv, ICMSR, RCAR_IRQ_ACK_RECV); return 0; } @@ -473,53 +363,31 @@ static int rcar_i2c_irq_recv(struct rcar_i2c_priv *priv, u32 msr) static irqreturn_t rcar_i2c_irq(int irq, void *ptr) { struct rcar_i2c_priv *priv = ptr; - struct device *dev = rcar_i2c_priv_to_dev(priv); u32 msr; - /*-------------- spin lock -----------------*/ - spin_lock(&priv->lock); - - msr = rcar_i2c_status_get(priv); + msr = rcar_i2c_read(priv, ICMSR); - /* - * Arbitration lost - */ + /* Arbitration lost */ if (msr & MAL) { - /* - * CAUTION - * - * When arbitration lost, device become _slave_ mode. - */ - dev_dbg(dev, "Arbitration Lost\n"); rcar_i2c_flags_set(priv, (ID_DONE | ID_ARBLOST)); goto out; } - /* - * Stop - */ + /* Stop */ if (msr & MST) { - dev_dbg(dev, "Stop\n"); rcar_i2c_flags_set(priv, ID_DONE); goto out; } - /* - * Nack - */ + /* Nack */ if (msr & MNR) { - dev_dbg(dev, "Nack\n"); - /* go to stop phase */ - rcar_i2c_bus_phase(priv, RCAR_BUS_PHASE_STOP); - rcar_i2c_irq_mask(priv, RCAR_IRQ_OPEN_FOR_STOP); + rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_STOP); + rcar_i2c_write(priv, ICMIER, RCAR_IRQ_STOP); rcar_i2c_flags_set(priv, ID_NACK); goto out; } - /* - * recv/send - */ if (rcar_i2c_is_recv(priv)) rcar_i2c_flags_set(priv, rcar_i2c_irq_recv(priv, msr)); else @@ -527,14 +395,11 @@ static irqreturn_t rcar_i2c_irq(int irq, void *ptr) out: if (rcar_i2c_flags_has(priv, ID_DONE)) { - rcar_i2c_irq_mask(priv, RCAR_IRQ_CLOSE); - rcar_i2c_status_clear(priv); + rcar_i2c_write(priv, ICMIER, 0); + rcar_i2c_write(priv, ICMSR, 0); wake_up(&priv->wait); } - spin_unlock(&priv->lock); - /*-------------- spin unlock -----------------*/ - return IRQ_HANDLED; } @@ -544,24 +409,24 @@ static int rcar_i2c_master_xfer(struct i2c_adapter *adap, { struct rcar_i2c_priv *priv = i2c_get_adapdata(adap); struct device *dev = rcar_i2c_priv_to_dev(priv); - unsigned long flags; int i, ret, timeout; pm_runtime_get_sync(dev); - /*-------------- spin lock -----------------*/ - spin_lock_irqsave(&priv->lock, flags); - rcar_i2c_init(priv); - rcar_i2c_clock_start(priv); + /* start clock */ + rcar_i2c_write(priv, ICCCR, priv->icccr); - spin_unlock_irqrestore(&priv->lock, flags); - /*-------------- spin unlock -----------------*/ + ret = rcar_i2c_bus_barrier(priv); + if (ret < 0) + goto out; - ret = -EINVAL; for (i = 0; i < num; i++) { - /*-------------- spin lock -----------------*/ - spin_lock_irqsave(&priv->lock, flags); + /* This HW can't send STOP after address phase */ + if (msgs[i].len == 0) { + ret = -EOPNOTSUPP; + break; + } /* init each data */ priv->msg = &msgs[i]; @@ -570,21 +435,11 @@ static int rcar_i2c_master_xfer(struct i2c_adapter *adap, if (priv->msg == &msgs[num - 1]) rcar_i2c_flags_set(priv, ID_LAST_MSG); - /* start send/recv */ - if (rcar_i2c_is_recv(priv)) - ret = rcar_i2c_recv(priv); - else - ret = rcar_i2c_send(priv); - - spin_unlock_irqrestore(&priv->lock, flags); - /*-------------- spin unlock -----------------*/ + ret = rcar_i2c_prepare_msg(priv); if (ret < 0) break; - /* - * wait result - */ timeout = wait_event_timeout(priv->wait, rcar_i2c_flags_has(priv, ID_DONE), 5 * HZ); @@ -593,11 +448,8 @@ static int rcar_i2c_master_xfer(struct i2c_adapter *adap, break; } - /* - * error handling - */ if (rcar_i2c_flags_has(priv, ID_NACK)) { - ret = -EREMOTEIO; + ret = -ENXIO; break; } @@ -613,10 +465,10 @@ static int rcar_i2c_master_xfer(struct i2c_adapter *adap, ret = i + 1; /* The number of transfer */ } - +out: pm_runtime_put(dev); - if (ret < 0) + if (ret < 0 && ret != -ENXIO) dev_err(dev, "error %d : %x\n", ret, priv->flags); return ret; @@ -624,7 +476,8 @@ static int rcar_i2c_master_xfer(struct i2c_adapter *adap, static u32 rcar_i2c_func(struct i2c_adapter *adap) { - return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; + /* This HW can't do SMBUS_QUICK and NOSTART */ + return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK); } static const struct i2c_algorithm rcar_i2c_algo = { @@ -632,6 +485,19 @@ static const struct i2c_algorithm rcar_i2c_algo = { .functionality = rcar_i2c_func, }; +static const struct of_device_id rcar_i2c_dt_ids[] = { + { .compatible = "renesas,i2c-rcar", .data = (void *)I2C_RCAR_GEN1 }, + { .compatible = "renesas,i2c-r8a7778", .data = (void *)I2C_RCAR_GEN1 }, + { .compatible = "renesas,i2c-r8a7779", .data = (void *)I2C_RCAR_GEN1 }, + { .compatible = "renesas,i2c-r8a7790", .data = (void *)I2C_RCAR_GEN2 }, + { .compatible = "renesas,i2c-r8a7791", .data = (void *)I2C_RCAR_GEN2 }, + { .compatible = "renesas,i2c-r8a7792", .data = (void *)I2C_RCAR_GEN2 }, + { .compatible = "renesas,i2c-r8a7793", .data = (void *)I2C_RCAR_GEN2 }, + { .compatible = "renesas,i2c-r8a7794", .data = (void *)I2C_RCAR_GEN2 }, + {}, +}; +MODULE_DEVICE_TABLE(of, rcar_i2c_dt_ids); + static int rcar_i2c_probe(struct platform_device *pdev) { struct i2c_rcar_platform_data *pdata = dev_get_platdata(&pdev->dev); @@ -640,19 +506,28 @@ static int rcar_i2c_probe(struct platform_device *pdev) struct resource *res; struct device *dev = &pdev->dev; u32 bus_speed; - int ret; + int irq, ret; priv = devm_kzalloc(dev, sizeof(struct rcar_i2c_priv), GFP_KERNEL); - if (!priv) { - dev_err(dev, "no mem for private data\n"); + if (!priv) return -ENOMEM; + + priv->clk = devm_clk_get(dev, NULL); + if (IS_ERR(priv->clk)) { + dev_err(dev, "cannot get clock\n"); + return PTR_ERR(priv->clk); } bus_speed = 100000; /* default 100 kHz */ - if (pdata && pdata->bus_speed) + ret = of_property_read_u32(dev->of_node, "clock-frequency", &bus_speed); + if (ret < 0 && pdata && pdata->bus_speed) bus_speed = pdata->bus_speed; - priv->devtype = platform_get_device_id(pdev)->driver_data; + if (pdev->dev.of_node) + priv->devtype = (long)of_match_device(rcar_i2c_dt_ids, + dev)->data; + else + priv->devtype = platform_get_device_id(pdev)->driver_data; ret = rcar_i2c_clock_calculate(priv, bus_speed, dev); if (ret < 0) @@ -663,23 +538,23 @@ static int rcar_i2c_probe(struct platform_device *pdev) if (IS_ERR(priv->io)) return PTR_ERR(priv->io); - priv->irq = platform_get_irq(pdev, 0); + irq = platform_get_irq(pdev, 0); init_waitqueue_head(&priv->wait); - spin_lock_init(&priv->lock); adap = &priv->adap; adap->nr = pdev->id; adap->algo = &rcar_i2c_algo; - adap->class = I2C_CLASS_HWMON | I2C_CLASS_SPD; + adap->class = I2C_CLASS_HWMON | I2C_CLASS_SPD | I2C_CLASS_DEPRECATED; adap->retries = 3; adap->dev.parent = dev; + adap->dev.of_node = dev->of_node; i2c_set_adapdata(adap, priv); strlcpy(adap->name, pdev->name, sizeof(adap->name)); - ret = devm_request_irq(dev, priv->irq, rcar_i2c_irq, 0, + ret = devm_request_irq(dev, irq, rcar_i2c_irq, 0, dev_name(dev), priv); if (ret < 0) { - dev_err(dev, "cannot get irq %d\n", priv->irq); + dev_err(dev, "cannot get irq %d\n", irq); return ret; } @@ -709,9 +584,9 @@ static int rcar_i2c_remove(struct platform_device *pdev) } static struct platform_device_id rcar_i2c_id_table[] = { - { "i2c-rcar", I2C_RCAR_H1 }, - { "i2c-rcar_h1", I2C_RCAR_H1 }, - { "i2c-rcar_h2", I2C_RCAR_H2 }, + { "i2c-rcar", I2C_RCAR_GEN1 }, + { "i2c-rcar_gen1", I2C_RCAR_GEN1 }, + { "i2c-rcar_gen2", I2C_RCAR_GEN2 }, {}, }; MODULE_DEVICE_TABLE(platform, rcar_i2c_id_table); @@ -720,6 +595,7 @@ static struct platform_driver rcar_i2c_driver = { .driver = { .name = "i2c-rcar", .owner = THIS_MODULE, + .of_match_table = rcar_i2c_dt_ids, }, .probe = rcar_i2c_probe, .remove = rcar_i2c_remove, @@ -728,6 +604,6 @@ static struct platform_driver rcar_i2c_driver = { module_platform_driver(rcar_i2c_driver); -MODULE_LICENSE("GPL"); +MODULE_LICENSE("GPL v2"); MODULE_DESCRIPTION("Renesas R-Car I2C bus driver"); MODULE_AUTHOR("Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>"); |
