diff options
Diffstat (limited to 'target/linux/brcm2708/patches-4.4/0046-Add-Chris-Boot-s-i2c-driver.patch')
-rw-r--r-- | target/linux/brcm2708/patches-4.4/0046-Add-Chris-Boot-s-i2c-driver.patch | 635 |
1 files changed, 0 insertions, 635 deletions
diff --git a/target/linux/brcm2708/patches-4.4/0046-Add-Chris-Boot-s-i2c-driver.patch b/target/linux/brcm2708/patches-4.4/0046-Add-Chris-Boot-s-i2c-driver.patch deleted file mode 100644 index 6730ee6fd8..0000000000 --- a/target/linux/brcm2708/patches-4.4/0046-Add-Chris-Boot-s-i2c-driver.patch +++ /dev/null @@ -1,635 +0,0 @@ -From 72181304010d3aa74cd2b98db592554a541ce4c2 Mon Sep 17 00:00:00 2001 -From: popcornmix <popcornmix@gmail.com> -Date: Wed, 17 Jun 2015 15:44:08 +0100 -Subject: [PATCH 046/170] Add Chris Boot's i2c driver -MIME-Version: 1.0 -Content-Type: text/plain; charset=UTF-8 -Content-Transfer-Encoding: 8bit - -i2c-bcm2708: fixed baudrate - -Fixed issue where the wrong CDIV value was set for baudrates below 3815 Hz (for 250MHz bus clock). -In that case the computed CDIV value was more than 0xffff. However the CDIV register width is only 16 bits. -This resulted in incorrect setting of CDIV and higher baudrate than intended. -Example: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0x1704 -> 42430Hz -After correction: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0xffff -> 3815Hz -The correct baudrate is shown in the log after the cdiv > 0xffff correction. - -Perform I2C combined transactions when possible - -Perform I2C combined transactions whenever possible, within the -restrictions of the Broadcomm Serial Controller. - -Disable DONE interrupt during TA poll - -Prevent interrupt from being triggered if poll is missed and transfer -starts and finishes. - -i2c: Make combined transactions optional and disabled by default - -i2c: bcm2708: add device tree support - -Add DT support to driver and add to .dtsi file. -Setup pins in .dts file. -i2c is disabled by default. - -Signed-off-by: Noralf Tronnes <notro@tronnes.org> - -bcm2708: don't register i2c controllers when using DT - -The devices for the i2c controllers are in the Device Tree. -Only register devices when not using DT. - -Signed-off-by: Noralf Tronnes <notro@tronnes.org> - -I2C: Only register the I2C device for the current board revision - -i2c_bcm2708: Fix clock reference counting - -Fix grabbing lock from atomic context in i2c driver - -2 main changes: -- check for timeouts in the bcm2708_bsc_setup function as indicated by this comment: - /* poll for transfer start bit (should only take 1-20 polls) */ - This implies that the setup function can now fail so account for this everywhere it's called -- Removed the clk_get_rate call from inside the setup function as it locks a mutex and that's not ok since we call it from under a spin lock. - -i2c-bcm2708: When using DT, leave the GPIO setup to pinctrl - -i2c-bcm2708: Increase timeouts to allow larger transfers - -Use the timeout value provided by the I2C_TIMEOUT ioctl when waiting -for completion. The default timeout is 1 second. - -See: https://github.com/raspberrypi/linux/issues/260 - -i2c-bcm2708/BCM270X_DT: Add support for I2C2 - -The third I2C bus (I2C2) is normally reserved for HDMI use. Careless -use of this bus can break an attached display - use with caution. - -It is recommended to disable accesses by VideoCore by setting -hdmi_ignore_edid=1 or hdmi_edid_file=1 in config.txt. - -The interface is disabled by default - enable using the -i2c2_iknowwhatimdoing DT parameter. - -bcm2708-spi: Don't use static pin configuration with DT - -Also remove superfluous error checking - the SPI framework ensures the -validity of the chip_select value. - -i2c-bcm2708: Remove non-DT support - -Signed-off-by: Noralf Trønnes <noralf@tronnes.org> ---- - drivers/i2c/busses/Kconfig | 21 +- - drivers/i2c/busses/Makefile | 2 + - drivers/i2c/busses/i2c-bcm2708.c | 493 +++++++++++++++++++++++++++++++++++++++ - 3 files changed, 515 insertions(+), 1 deletion(-) - create mode 100644 drivers/i2c/busses/i2c-bcm2708.c - ---- a/drivers/i2c/busses/Kconfig -+++ b/drivers/i2c/busses/Kconfig -@@ -8,6 +8,25 @@ menu "I2C Hardware Bus support" - comment "PC SMBus host controller drivers" - depends on PCI - -+config I2C_BCM2708 -+ tristate "BCM2708 BSC" -+ depends on MACH_BCM2708 || MACH_BCM2709 || ARCH_BCM2835 -+ help -+ Enabling this option will add BSC (Broadcom Serial Controller) -+ support for the BCM2708. BSC is a Broadcom proprietary bus compatible -+ with I2C/TWI/SMBus. -+ -+config I2C_BCM2708_BAUDRATE -+ prompt "BCM2708 I2C baudrate" -+ depends on I2C_BCM2708 -+ int -+ default 100000 -+ help -+ Set the I2C baudrate. This will alter the default value. A -+ different baudrate can be set by using a module parameter as well. If -+ no parameter is provided when loading, this is the value that will be -+ used. -+ - config I2C_ALI1535 - tristate "ALI 1535" - depends on PCI -@@ -365,7 +384,7 @@ config I2C_AXXIA - - config I2C_BCM2835 - tristate "Broadcom BCM2835 I2C controller" -- depends on ARCH_BCM2835 -+ depends on ARCH_BCM2835 || ARCH_BCM2708 || ARCH_BCM2709 - help - If you say yes to this option, support will be included for the - BCM2835 I2C controller. ---- a/drivers/i2c/busses/Makefile -+++ b/drivers/i2c/busses/Makefile -@@ -2,6 +2,8 @@ - # Makefile for the i2c bus drivers. - # - -+obj-$(CONFIG_I2C_BCM2708) += i2c-bcm2708.o -+ - # ACPI drivers - obj-$(CONFIG_I2C_SCMI) += i2c-scmi.o - ---- /dev/null -+++ b/drivers/i2c/busses/i2c-bcm2708.c -@@ -0,0 +1,493 @@ -+/* -+ * Driver for Broadcom BCM2708 BSC Controllers -+ * -+ * Copyright (C) 2012 Chris Boot & Frank Buss -+ * -+ * This driver is inspired by: -+ * i2c-ocores.c, by Peter Korsgaard <jacmet@sunsite.dk> -+ * -+ * 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, or -+ * (at your option) any later version. -+ * -+ * 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/kernel.h> -+#include <linux/module.h> -+#include <linux/spinlock.h> -+#include <linux/clk.h> -+#include <linux/err.h> -+#include <linux/of.h> -+#include <linux/platform_device.h> -+#include <linux/io.h> -+#include <linux/slab.h> -+#include <linux/i2c.h> -+#include <linux/interrupt.h> -+#include <linux/sched.h> -+#include <linux/wait.h> -+ -+/* BSC register offsets */ -+#define BSC_C 0x00 -+#define BSC_S 0x04 -+#define BSC_DLEN 0x08 -+#define BSC_A 0x0c -+#define BSC_FIFO 0x10 -+#define BSC_DIV 0x14 -+#define BSC_DEL 0x18 -+#define BSC_CLKT 0x1c -+ -+/* Bitfields in BSC_C */ -+#define BSC_C_I2CEN 0x00008000 -+#define BSC_C_INTR 0x00000400 -+#define BSC_C_INTT 0x00000200 -+#define BSC_C_INTD 0x00000100 -+#define BSC_C_ST 0x00000080 -+#define BSC_C_CLEAR_1 0x00000020 -+#define BSC_C_CLEAR_2 0x00000010 -+#define BSC_C_READ 0x00000001 -+ -+/* Bitfields in BSC_S */ -+#define BSC_S_CLKT 0x00000200 -+#define BSC_S_ERR 0x00000100 -+#define BSC_S_RXF 0x00000080 -+#define BSC_S_TXE 0x00000040 -+#define BSC_S_RXD 0x00000020 -+#define BSC_S_TXD 0x00000010 -+#define BSC_S_RXR 0x00000008 -+#define BSC_S_TXW 0x00000004 -+#define BSC_S_DONE 0x00000002 -+#define BSC_S_TA 0x00000001 -+ -+#define I2C_WAIT_LOOP_COUNT 200 -+ -+#define DRV_NAME "bcm2708_i2c" -+ -+static unsigned int baudrate = CONFIG_I2C_BCM2708_BAUDRATE; -+module_param(baudrate, uint, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP); -+MODULE_PARM_DESC(baudrate, "The I2C baudrate"); -+ -+static bool combined = false; -+module_param(combined, bool, 0644); -+MODULE_PARM_DESC(combined, "Use combined transactions"); -+ -+struct bcm2708_i2c { -+ struct i2c_adapter adapter; -+ -+ spinlock_t lock; -+ void __iomem *base; -+ int irq; -+ struct clk *clk; -+ u32 cdiv; -+ -+ struct completion done; -+ -+ struct i2c_msg *msg; -+ int pos; -+ int nmsgs; -+ bool error; -+}; -+ -+static inline u32 bcm2708_rd(struct bcm2708_i2c *bi, unsigned reg) -+{ -+ return readl(bi->base + reg); -+} -+ -+static inline void bcm2708_wr(struct bcm2708_i2c *bi, unsigned reg, u32 val) -+{ -+ writel(val, bi->base + reg); -+} -+ -+static inline void bcm2708_bsc_reset(struct bcm2708_i2c *bi) -+{ -+ bcm2708_wr(bi, BSC_C, 0); -+ bcm2708_wr(bi, BSC_S, BSC_S_CLKT | BSC_S_ERR | BSC_S_DONE); -+} -+ -+static inline void bcm2708_bsc_fifo_drain(struct bcm2708_i2c *bi) -+{ -+ while ((bcm2708_rd(bi, BSC_S) & BSC_S_RXD) && (bi->pos < bi->msg->len)) -+ bi->msg->buf[bi->pos++] = bcm2708_rd(bi, BSC_FIFO); -+} -+ -+static inline void bcm2708_bsc_fifo_fill(struct bcm2708_i2c *bi) -+{ -+ while ((bcm2708_rd(bi, BSC_S) & BSC_S_TXD) && (bi->pos < bi->msg->len)) -+ bcm2708_wr(bi, BSC_FIFO, bi->msg->buf[bi->pos++]); -+} -+ -+static inline int bcm2708_bsc_setup(struct bcm2708_i2c *bi) -+{ -+ u32 cdiv, s; -+ u32 c = BSC_C_I2CEN | BSC_C_INTD | BSC_C_ST | BSC_C_CLEAR_1; -+ int wait_loops = I2C_WAIT_LOOP_COUNT; -+ -+ /* Can't call clk_get_rate as it locks a mutex and here we are spinlocked. -+ * Use the value that we cached in the probe. -+ */ -+ cdiv = bi->cdiv; -+ -+ if (bi->msg->flags & I2C_M_RD) -+ c |= BSC_C_INTR | BSC_C_READ; -+ else -+ c |= BSC_C_INTT; -+ -+ bcm2708_wr(bi, BSC_DIV, cdiv); -+ bcm2708_wr(bi, BSC_A, bi->msg->addr); -+ bcm2708_wr(bi, BSC_DLEN, bi->msg->len); -+ if (combined) -+ { -+ /* Do the next two messages meet combined transaction criteria? -+ - Current message is a write, next message is a read -+ - Both messages to same slave address -+ - Write message can fit inside FIFO (16 bytes or less) */ -+ if ( (bi->nmsgs > 1) && -+ !(bi->msg[0].flags & I2C_M_RD) && (bi->msg[1].flags & I2C_M_RD) && -+ (bi->msg[0].addr == bi->msg[1].addr) && (bi->msg[0].len <= 16)) { -+ /* Fill FIFO with entire write message (16 byte FIFO) */ -+ while (bi->pos < bi->msg->len) { -+ bcm2708_wr(bi, BSC_FIFO, bi->msg->buf[bi->pos++]); -+ } -+ /* Start write transfer (no interrupts, don't clear FIFO) */ -+ bcm2708_wr(bi, BSC_C, BSC_C_I2CEN | BSC_C_ST); -+ -+ /* poll for transfer start bit (should only take 1-20 polls) */ -+ do { -+ s = bcm2708_rd(bi, BSC_S); -+ } while (!(s & (BSC_S_TA | BSC_S_ERR | BSC_S_CLKT | BSC_S_DONE)) && --wait_loops >= 0); -+ -+ /* did we time out or some error occured? */ -+ if (wait_loops < 0 || (s & (BSC_S_ERR | BSC_S_CLKT))) { -+ return -1; -+ } -+ -+ /* Send next read message before the write transfer finishes. */ -+ bi->nmsgs--; -+ bi->msg++; -+ bi->pos = 0; -+ bcm2708_wr(bi, BSC_DLEN, bi->msg->len); -+ c = BSC_C_I2CEN | BSC_C_INTD | BSC_C_INTR | BSC_C_ST | BSC_C_READ; -+ } -+ } -+ bcm2708_wr(bi, BSC_C, c); -+ -+ return 0; -+} -+ -+static irqreturn_t bcm2708_i2c_interrupt(int irq, void *dev_id) -+{ -+ struct bcm2708_i2c *bi = dev_id; -+ bool handled = true; -+ u32 s; -+ int ret; -+ -+ spin_lock(&bi->lock); -+ -+ /* we may see camera interrupts on the "other" I2C channel -+ Just return if we've not sent anything */ -+ if (!bi->nmsgs || !bi->msg) { -+ goto early_exit; -+ } -+ -+ s = bcm2708_rd(bi, BSC_S); -+ -+ if (s & (BSC_S_CLKT | BSC_S_ERR)) { -+ bcm2708_bsc_reset(bi); -+ bi->error = true; -+ -+ bi->msg = 0; /* to inform the that all work is done */ -+ bi->nmsgs = 0; -+ /* wake up our bh */ -+ complete(&bi->done); -+ } else if (s & BSC_S_DONE) { -+ bi->nmsgs--; -+ -+ if (bi->msg->flags & I2C_M_RD) { -+ bcm2708_bsc_fifo_drain(bi); -+ } -+ -+ bcm2708_bsc_reset(bi); -+ -+ if (bi->nmsgs) { -+ /* advance to next message */ -+ bi->msg++; -+ bi->pos = 0; -+ ret = bcm2708_bsc_setup(bi); -+ if (ret < 0) { -+ bcm2708_bsc_reset(bi); -+ bi->error = true; -+ bi->msg = 0; /* to inform the that all work is done */ -+ bi->nmsgs = 0; -+ /* wake up our bh */ -+ complete(&bi->done); -+ goto early_exit; -+ } -+ } else { -+ bi->msg = 0; /* to inform the that all work is done */ -+ bi->nmsgs = 0; -+ /* wake up our bh */ -+ complete(&bi->done); -+ } -+ } else if (s & BSC_S_TXW) { -+ bcm2708_bsc_fifo_fill(bi); -+ } else if (s & BSC_S_RXR) { -+ bcm2708_bsc_fifo_drain(bi); -+ } else { -+ handled = false; -+ } -+ -+early_exit: -+ spin_unlock(&bi->lock); -+ -+ return handled ? IRQ_HANDLED : IRQ_NONE; -+} -+ -+static int bcm2708_i2c_master_xfer(struct i2c_adapter *adap, -+ struct i2c_msg *msgs, int num) -+{ -+ struct bcm2708_i2c *bi = adap->algo_data; -+ unsigned long flags; -+ int ret; -+ -+ spin_lock_irqsave(&bi->lock, flags); -+ -+ reinit_completion(&bi->done); -+ bi->msg = msgs; -+ bi->pos = 0; -+ bi->nmsgs = num; -+ bi->error = false; -+ -+ ret = bcm2708_bsc_setup(bi); -+ -+ spin_unlock_irqrestore(&bi->lock, flags); -+ -+ /* check the result of the setup */ -+ if (ret < 0) -+ { -+ dev_err(&adap->dev, "transfer setup timed out\n"); -+ goto error_timeout; -+ } -+ -+ ret = wait_for_completion_timeout(&bi->done, adap->timeout); -+ if (ret == 0) { -+ dev_err(&adap->dev, "transfer timed out\n"); -+ goto error_timeout; -+ } -+ -+ ret = bi->error ? -EIO : num; -+ return ret; -+ -+error_timeout: -+ spin_lock_irqsave(&bi->lock, flags); -+ bcm2708_bsc_reset(bi); -+ bi->msg = 0; /* to inform the interrupt handler that there's nothing else to be done */ -+ bi->nmsgs = 0; -+ spin_unlock_irqrestore(&bi->lock, flags); -+ return -ETIMEDOUT; -+} -+ -+static u32 bcm2708_i2c_functionality(struct i2c_adapter *adap) -+{ -+ return I2C_FUNC_I2C | /*I2C_FUNC_10BIT_ADDR |*/ I2C_FUNC_SMBUS_EMUL; -+} -+ -+static struct i2c_algorithm bcm2708_i2c_algorithm = { -+ .master_xfer = bcm2708_i2c_master_xfer, -+ .functionality = bcm2708_i2c_functionality, -+}; -+ -+static int bcm2708_i2c_probe(struct platform_device *pdev) -+{ -+ struct resource *regs; -+ int irq, err = -ENOMEM; -+ struct clk *clk; -+ struct bcm2708_i2c *bi; -+ struct i2c_adapter *adap; -+ unsigned long bus_hz; -+ u32 cdiv; -+ -+ if (pdev->dev.of_node) { -+ u32 bus_clk_rate; -+ pdev->id = of_alias_get_id(pdev->dev.of_node, "i2c"); -+ if (pdev->id < 0) { -+ dev_err(&pdev->dev, "alias is missing\n"); -+ return -EINVAL; -+ } -+ if (!of_property_read_u32(pdev->dev.of_node, -+ "clock-frequency", &bus_clk_rate)) -+ baudrate = bus_clk_rate; -+ else -+ dev_warn(&pdev->dev, -+ "Could not read clock-frequency property\n"); -+ } -+ -+ regs = platform_get_resource(pdev, IORESOURCE_MEM, 0); -+ if (!regs) { -+ dev_err(&pdev->dev, "could not get IO memory\n"); -+ return -ENXIO; -+ } -+ -+ irq = platform_get_irq(pdev, 0); -+ if (irq < 0) { -+ dev_err(&pdev->dev, "could not get IRQ\n"); -+ return irq; -+ } -+ -+ clk = clk_get(&pdev->dev, NULL); -+ if (IS_ERR(clk)) { -+ dev_err(&pdev->dev, "could not find clk: %ld\n", PTR_ERR(clk)); -+ return PTR_ERR(clk); -+ } -+ -+ err = clk_prepare_enable(clk); -+ if (err) { -+ dev_err(&pdev->dev, "could not enable clk: %d\n", err); -+ goto out_clk_put; -+ } -+ -+ bi = kzalloc(sizeof(*bi), GFP_KERNEL); -+ if (!bi) -+ goto out_clk_disable; -+ -+ platform_set_drvdata(pdev, bi); -+ -+ adap = &bi->adapter; -+ adap->class = I2C_CLASS_HWMON | I2C_CLASS_DDC; -+ adap->algo = &bcm2708_i2c_algorithm; -+ adap->algo_data = bi; -+ adap->dev.parent = &pdev->dev; -+ adap->nr = pdev->id; -+ strlcpy(adap->name, dev_name(&pdev->dev), sizeof(adap->name)); -+ adap->dev.of_node = pdev->dev.of_node; -+ -+ switch (pdev->id) { -+ case 0: -+ adap->class = I2C_CLASS_HWMON; -+ break; -+ case 1: -+ adap->class = I2C_CLASS_DDC; -+ break; -+ case 2: -+ adap->class = I2C_CLASS_DDC; -+ break; -+ default: -+ dev_err(&pdev->dev, "can only bind to BSC 0, 1 or 2\n"); -+ err = -ENXIO; -+ goto out_free_bi; -+ } -+ -+ spin_lock_init(&bi->lock); -+ init_completion(&bi->done); -+ -+ bi->base = ioremap(regs->start, resource_size(regs)); -+ if (!bi->base) { -+ dev_err(&pdev->dev, "could not remap memory\n"); -+ goto out_free_bi; -+ } -+ -+ bi->irq = irq; -+ bi->clk = clk; -+ -+ err = request_irq(irq, bcm2708_i2c_interrupt, IRQF_SHARED, -+ dev_name(&pdev->dev), bi); -+ if (err) { -+ dev_err(&pdev->dev, "could not request IRQ: %d\n", err); -+ goto out_iounmap; -+ } -+ -+ bcm2708_bsc_reset(bi); -+ -+ err = i2c_add_numbered_adapter(adap); -+ if (err < 0) { -+ dev_err(&pdev->dev, "could not add I2C adapter: %d\n", err); -+ goto out_free_irq; -+ } -+ -+ bus_hz = clk_get_rate(bi->clk); -+ cdiv = bus_hz / baudrate; -+ if (cdiv > 0xffff) { -+ cdiv = 0xffff; -+ baudrate = bus_hz / cdiv; -+ } -+ bi->cdiv = cdiv; -+ -+ dev_info(&pdev->dev, "BSC%d Controller at 0x%08lx (irq %d) (baudrate %d)\n", -+ pdev->id, (unsigned long)regs->start, irq, baudrate); -+ -+ return 0; -+ -+out_free_irq: -+ free_irq(bi->irq, bi); -+out_iounmap: -+ iounmap(bi->base); -+out_free_bi: -+ kfree(bi); -+out_clk_disable: -+ clk_disable_unprepare(clk); -+out_clk_put: -+ clk_put(clk); -+ return err; -+} -+ -+static int bcm2708_i2c_remove(struct platform_device *pdev) -+{ -+ struct bcm2708_i2c *bi = platform_get_drvdata(pdev); -+ -+ platform_set_drvdata(pdev, NULL); -+ -+ i2c_del_adapter(&bi->adapter); -+ free_irq(bi->irq, bi); -+ iounmap(bi->base); -+ clk_disable_unprepare(bi->clk); -+ clk_put(bi->clk); -+ kfree(bi); -+ -+ return 0; -+} -+ -+static const struct of_device_id bcm2708_i2c_of_match[] = { -+ { .compatible = "brcm,bcm2708-i2c" }, -+ {}, -+}; -+MODULE_DEVICE_TABLE(of, bcm2708_i2c_of_match); -+ -+static struct platform_driver bcm2708_i2c_driver = { -+ .driver = { -+ .name = DRV_NAME, -+ .owner = THIS_MODULE, -+ .of_match_table = bcm2708_i2c_of_match, -+ }, -+ .probe = bcm2708_i2c_probe, -+ .remove = bcm2708_i2c_remove, -+}; -+ -+// module_platform_driver(bcm2708_i2c_driver); -+ -+ -+static int __init bcm2708_i2c_init(void) -+{ -+ return platform_driver_register(&bcm2708_i2c_driver); -+} -+ -+static void __exit bcm2708_i2c_exit(void) -+{ -+ platform_driver_unregister(&bcm2708_i2c_driver); -+} -+ -+module_init(bcm2708_i2c_init); -+module_exit(bcm2708_i2c_exit); -+ -+ -+ -+MODULE_DESCRIPTION("BSC controller driver for Broadcom BCM2708"); -+MODULE_AUTHOR("Chris Boot <bootc@bootc.net>"); -+MODULE_LICENSE("GPL v2"); -+MODULE_ALIAS("platform:" DRV_NAME); |