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![Stefan Brüns](/assets/img/avatar_default.png)
Include the OF-based modalias in the uevent sent when registering devices on the sunxi RSB bus, so that user space has a chance to autoload the kernel module for the device. Fixes a regression caused by commit3f241bfa60
("arm64: allwinner: a64: pine64: Use dcdc1 regulator for mmc0"). When the axp20x-rsb module for the AXP803 PMIC is built as a module, it is not loaded and the system ends up with an disfunctional MMC controller. Fixes:d787dcdb9c
("bus: sunxi-rsb: Add driver for Allwinner Reduced Serial Bus") Cc: stable <stable@vger.kernel.org> # 4.4.x7a3b7cd332
of: device: Export of_device_{get_modalias, uvent_modalias} to modules Acked-by: Chen-Yu Tsai <wens@csie.org> Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
784 lines
19 KiB
C
784 lines
19 KiB
C
/*
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* RSB (Reduced Serial Bus) driver.
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*
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* Author: Chen-Yu Tsai <wens@csie.org>
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*
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* This file is licensed under the terms of the GNU General Public License
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* version 2. This program is licensed "as is" without any warranty of any
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* kind, whether express or implied.
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*
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* The RSB controller looks like an SMBus controller which only supports
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* byte and word data transfers. But, it differs from standard SMBus
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* protocol on several aspects:
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* - it uses addresses set at runtime to address slaves. Runtime addresses
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* are sent to slaves using their 12bit hardware addresses. Up to 15
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* runtime addresses are available.
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* - it adds a parity bit every 8bits of data and address for read and
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* write accesses; this replaces the ack bit
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* - only one read access is required to read a byte (instead of a write
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* followed by a read access in standard SMBus protocol)
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* - there's no Ack bit after each read access
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*
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* This means this bus cannot be used to interface with standard SMBus
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* devices. Devices known to support this interface include the AXP223,
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* AXP809, and AXP806 PMICs, and the AC100 audio codec, all from X-Powers.
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*
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* A description of the operation and wire protocol can be found in the
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* RSB section of Allwinner's A80 user manual, which can be found at
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*
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* https://github.com/allwinner-zh/documents/tree/master/A80
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*
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* This document is officially released by Allwinner.
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*
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* This driver is based on i2c-sun6i-p2wi.c, the P2WI bus driver.
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*
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*/
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#include <linux/clk.h>
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#include <linux/clk/clk-conf.h>
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#include <linux/device.h>
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#include <linux/interrupt.h>
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#include <linux/io.h>
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#include <linux/iopoll.h>
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#include <linux/module.h>
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#include <linux/of.h>
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#include <linux/of_irq.h>
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#include <linux/of_platform.h>
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#include <linux/platform_device.h>
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#include <linux/regmap.h>
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#include <linux/reset.h>
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#include <linux/slab.h>
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#include <linux/sunxi-rsb.h>
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#include <linux/types.h>
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/* RSB registers */
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#define RSB_CTRL 0x0 /* Global control */
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#define RSB_CCR 0x4 /* Clock control */
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#define RSB_INTE 0x8 /* Interrupt controls */
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#define RSB_INTS 0xc /* Interrupt status */
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#define RSB_ADDR 0x10 /* Address to send with read/write command */
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#define RSB_DATA 0x1c /* Data to read/write */
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#define RSB_LCR 0x24 /* Line control */
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#define RSB_DMCR 0x28 /* Device mode (init) control */
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#define RSB_CMD 0x2c /* RSB Command */
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#define RSB_DAR 0x30 /* Device address / runtime address */
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/* CTRL fields */
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#define RSB_CTRL_START_TRANS BIT(7)
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#define RSB_CTRL_ABORT_TRANS BIT(6)
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#define RSB_CTRL_GLOBAL_INT_ENB BIT(1)
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#define RSB_CTRL_SOFT_RST BIT(0)
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/* CLK CTRL fields */
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#define RSB_CCR_SDA_OUT_DELAY(v) (((v) & 0x7) << 8)
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#define RSB_CCR_MAX_CLK_DIV 0xff
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#define RSB_CCR_CLK_DIV(v) ((v) & RSB_CCR_MAX_CLK_DIV)
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/* STATUS fields */
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#define RSB_INTS_TRANS_ERR_ACK BIT(16)
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#define RSB_INTS_TRANS_ERR_DATA_BIT(v) (((v) >> 8) & 0xf)
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#define RSB_INTS_TRANS_ERR_DATA GENMASK(11, 8)
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#define RSB_INTS_LOAD_BSY BIT(2)
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#define RSB_INTS_TRANS_ERR BIT(1)
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#define RSB_INTS_TRANS_OVER BIT(0)
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/* LINE CTRL fields*/
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#define RSB_LCR_SCL_STATE BIT(5)
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#define RSB_LCR_SDA_STATE BIT(4)
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#define RSB_LCR_SCL_CTL BIT(3)
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#define RSB_LCR_SCL_CTL_EN BIT(2)
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#define RSB_LCR_SDA_CTL BIT(1)
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#define RSB_LCR_SDA_CTL_EN BIT(0)
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/* DEVICE MODE CTRL field values */
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#define RSB_DMCR_DEVICE_START BIT(31)
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#define RSB_DMCR_MODE_DATA (0x7c << 16)
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#define RSB_DMCR_MODE_REG (0x3e << 8)
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#define RSB_DMCR_DEV_ADDR 0x00
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/* CMD values */
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#define RSB_CMD_RD8 0x8b
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#define RSB_CMD_RD16 0x9c
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#define RSB_CMD_RD32 0xa6
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#define RSB_CMD_WR8 0x4e
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#define RSB_CMD_WR16 0x59
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#define RSB_CMD_WR32 0x63
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#define RSB_CMD_STRA 0xe8
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/* DAR fields */
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#define RSB_DAR_RTA(v) (((v) & 0xff) << 16)
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#define RSB_DAR_DA(v) ((v) & 0xffff)
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#define RSB_MAX_FREQ 20000000
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#define RSB_CTRL_NAME "sunxi-rsb"
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struct sunxi_rsb_addr_map {
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u16 hwaddr;
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u8 rtaddr;
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};
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struct sunxi_rsb {
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struct device *dev;
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void __iomem *regs;
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struct clk *clk;
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struct reset_control *rstc;
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struct completion complete;
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struct mutex lock;
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unsigned int status;
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};
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/* bus / slave device related functions */
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static struct bus_type sunxi_rsb_bus;
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static int sunxi_rsb_device_match(struct device *dev, struct device_driver *drv)
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{
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return of_driver_match_device(dev, drv);
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}
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static int sunxi_rsb_device_probe(struct device *dev)
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{
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const struct sunxi_rsb_driver *drv = to_sunxi_rsb_driver(dev->driver);
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struct sunxi_rsb_device *rdev = to_sunxi_rsb_device(dev);
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int ret;
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if (!drv->probe)
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return -ENODEV;
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if (!rdev->irq) {
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int irq = -ENOENT;
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if (dev->of_node)
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irq = of_irq_get(dev->of_node, 0);
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if (irq == -EPROBE_DEFER)
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return irq;
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if (irq < 0)
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irq = 0;
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rdev->irq = irq;
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}
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ret = of_clk_set_defaults(dev->of_node, false);
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if (ret < 0)
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return ret;
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return drv->probe(rdev);
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}
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static int sunxi_rsb_device_remove(struct device *dev)
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{
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const struct sunxi_rsb_driver *drv = to_sunxi_rsb_driver(dev->driver);
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return drv->remove(to_sunxi_rsb_device(dev));
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}
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static struct bus_type sunxi_rsb_bus = {
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.name = RSB_CTRL_NAME,
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.match = sunxi_rsb_device_match,
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.probe = sunxi_rsb_device_probe,
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.remove = sunxi_rsb_device_remove,
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.uevent = of_device_uevent_modalias,
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};
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static void sunxi_rsb_dev_release(struct device *dev)
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{
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struct sunxi_rsb_device *rdev = to_sunxi_rsb_device(dev);
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kfree(rdev);
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}
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/**
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* sunxi_rsb_device_create() - allocate and add an RSB device
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* @rsb: RSB controller
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* @node: RSB slave device node
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* @hwaddr: RSB slave hardware address
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* @rtaddr: RSB slave runtime address
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*/
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static struct sunxi_rsb_device *sunxi_rsb_device_create(struct sunxi_rsb *rsb,
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struct device_node *node, u16 hwaddr, u8 rtaddr)
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{
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int err;
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struct sunxi_rsb_device *rdev;
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rdev = kzalloc(sizeof(*rdev), GFP_KERNEL);
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if (!rdev)
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return ERR_PTR(-ENOMEM);
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rdev->rsb = rsb;
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rdev->hwaddr = hwaddr;
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rdev->rtaddr = rtaddr;
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rdev->dev.bus = &sunxi_rsb_bus;
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rdev->dev.parent = rsb->dev;
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rdev->dev.of_node = node;
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rdev->dev.release = sunxi_rsb_dev_release;
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dev_set_name(&rdev->dev, "%s-%x", RSB_CTRL_NAME, hwaddr);
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err = device_register(&rdev->dev);
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if (err < 0) {
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dev_err(&rdev->dev, "Can't add %s, status %d\n",
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dev_name(&rdev->dev), err);
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goto err_device_add;
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}
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dev_dbg(&rdev->dev, "device %s registered\n", dev_name(&rdev->dev));
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err_device_add:
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put_device(&rdev->dev);
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return ERR_PTR(err);
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}
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/**
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* sunxi_rsb_device_unregister(): unregister an RSB device
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* @rdev: rsb_device to be removed
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*/
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static void sunxi_rsb_device_unregister(struct sunxi_rsb_device *rdev)
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{
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device_unregister(&rdev->dev);
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}
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static int sunxi_rsb_remove_devices(struct device *dev, void *data)
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{
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struct sunxi_rsb_device *rdev = to_sunxi_rsb_device(dev);
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if (dev->bus == &sunxi_rsb_bus)
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sunxi_rsb_device_unregister(rdev);
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return 0;
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}
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/**
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* sunxi_rsb_driver_register() - Register device driver with RSB core
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* @rdrv: device driver to be associated with slave-device.
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*
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* This API will register the client driver with the RSB framework.
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* It is typically called from the driver's module-init function.
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*/
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int sunxi_rsb_driver_register(struct sunxi_rsb_driver *rdrv)
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{
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rdrv->driver.bus = &sunxi_rsb_bus;
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return driver_register(&rdrv->driver);
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}
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EXPORT_SYMBOL_GPL(sunxi_rsb_driver_register);
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/* common code that starts a transfer */
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static int _sunxi_rsb_run_xfer(struct sunxi_rsb *rsb)
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{
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if (readl(rsb->regs + RSB_CTRL) & RSB_CTRL_START_TRANS) {
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dev_dbg(rsb->dev, "RSB transfer still in progress\n");
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return -EBUSY;
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}
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reinit_completion(&rsb->complete);
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writel(RSB_INTS_LOAD_BSY | RSB_INTS_TRANS_ERR | RSB_INTS_TRANS_OVER,
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rsb->regs + RSB_INTE);
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writel(RSB_CTRL_START_TRANS | RSB_CTRL_GLOBAL_INT_ENB,
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rsb->regs + RSB_CTRL);
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if (!wait_for_completion_io_timeout(&rsb->complete,
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msecs_to_jiffies(100))) {
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dev_dbg(rsb->dev, "RSB timeout\n");
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/* abort the transfer */
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writel(RSB_CTRL_ABORT_TRANS, rsb->regs + RSB_CTRL);
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/* clear any interrupt flags */
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writel(readl(rsb->regs + RSB_INTS), rsb->regs + RSB_INTS);
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return -ETIMEDOUT;
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}
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if (rsb->status & RSB_INTS_LOAD_BSY) {
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dev_dbg(rsb->dev, "RSB busy\n");
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return -EBUSY;
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}
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if (rsb->status & RSB_INTS_TRANS_ERR) {
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if (rsb->status & RSB_INTS_TRANS_ERR_ACK) {
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dev_dbg(rsb->dev, "RSB slave nack\n");
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return -EINVAL;
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}
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if (rsb->status & RSB_INTS_TRANS_ERR_DATA) {
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dev_dbg(rsb->dev, "RSB transfer data error\n");
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return -EIO;
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}
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}
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return 0;
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}
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static int sunxi_rsb_read(struct sunxi_rsb *rsb, u8 rtaddr, u8 addr,
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u32 *buf, size_t len)
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{
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u32 cmd;
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int ret;
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if (!buf)
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return -EINVAL;
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switch (len) {
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case 1:
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cmd = RSB_CMD_RD8;
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break;
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case 2:
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cmd = RSB_CMD_RD16;
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break;
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case 4:
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cmd = RSB_CMD_RD32;
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break;
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default:
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dev_err(rsb->dev, "Invalid access width: %zd\n", len);
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return -EINVAL;
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}
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mutex_lock(&rsb->lock);
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writel(addr, rsb->regs + RSB_ADDR);
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writel(RSB_DAR_RTA(rtaddr), rsb->regs + RSB_DAR);
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writel(cmd, rsb->regs + RSB_CMD);
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ret = _sunxi_rsb_run_xfer(rsb);
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if (ret)
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goto unlock;
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*buf = readl(rsb->regs + RSB_DATA);
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unlock:
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mutex_unlock(&rsb->lock);
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return ret;
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}
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static int sunxi_rsb_write(struct sunxi_rsb *rsb, u8 rtaddr, u8 addr,
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const u32 *buf, size_t len)
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{
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u32 cmd;
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int ret;
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if (!buf)
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return -EINVAL;
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switch (len) {
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case 1:
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cmd = RSB_CMD_WR8;
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break;
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case 2:
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cmd = RSB_CMD_WR16;
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break;
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case 4:
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cmd = RSB_CMD_WR32;
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break;
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default:
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dev_err(rsb->dev, "Invalid access width: %zd\n", len);
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return -EINVAL;
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}
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mutex_lock(&rsb->lock);
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writel(addr, rsb->regs + RSB_ADDR);
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writel(RSB_DAR_RTA(rtaddr), rsb->regs + RSB_DAR);
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writel(*buf, rsb->regs + RSB_DATA);
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writel(cmd, rsb->regs + RSB_CMD);
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ret = _sunxi_rsb_run_xfer(rsb);
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mutex_unlock(&rsb->lock);
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return ret;
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}
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/* RSB regmap functions */
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struct sunxi_rsb_ctx {
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struct sunxi_rsb_device *rdev;
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int size;
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};
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static int regmap_sunxi_rsb_reg_read(void *context, unsigned int reg,
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unsigned int *val)
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{
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struct sunxi_rsb_ctx *ctx = context;
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struct sunxi_rsb_device *rdev = ctx->rdev;
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if (reg > 0xff)
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return -EINVAL;
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return sunxi_rsb_read(rdev->rsb, rdev->rtaddr, reg, val, ctx->size);
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}
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static int regmap_sunxi_rsb_reg_write(void *context, unsigned int reg,
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unsigned int val)
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{
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struct sunxi_rsb_ctx *ctx = context;
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struct sunxi_rsb_device *rdev = ctx->rdev;
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return sunxi_rsb_write(rdev->rsb, rdev->rtaddr, reg, &val, ctx->size);
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}
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static void regmap_sunxi_rsb_free_ctx(void *context)
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{
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struct sunxi_rsb_ctx *ctx = context;
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kfree(ctx);
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}
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static struct regmap_bus regmap_sunxi_rsb = {
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.reg_write = regmap_sunxi_rsb_reg_write,
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.reg_read = regmap_sunxi_rsb_reg_read,
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.free_context = regmap_sunxi_rsb_free_ctx,
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.reg_format_endian_default = REGMAP_ENDIAN_NATIVE,
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.val_format_endian_default = REGMAP_ENDIAN_NATIVE,
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};
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static struct sunxi_rsb_ctx *regmap_sunxi_rsb_init_ctx(struct sunxi_rsb_device *rdev,
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const struct regmap_config *config)
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{
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struct sunxi_rsb_ctx *ctx;
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switch (config->val_bits) {
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case 8:
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case 16:
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case 32:
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break;
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default:
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return ERR_PTR(-EINVAL);
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}
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ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
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if (!ctx)
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return ERR_PTR(-ENOMEM);
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ctx->rdev = rdev;
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ctx->size = config->val_bits / 8;
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return ctx;
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}
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struct regmap *__devm_regmap_init_sunxi_rsb(struct sunxi_rsb_device *rdev,
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const struct regmap_config *config,
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struct lock_class_key *lock_key,
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const char *lock_name)
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{
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struct sunxi_rsb_ctx *ctx = regmap_sunxi_rsb_init_ctx(rdev, config);
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if (IS_ERR(ctx))
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return ERR_CAST(ctx);
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return __devm_regmap_init(&rdev->dev, ®map_sunxi_rsb, ctx, config,
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lock_key, lock_name);
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}
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EXPORT_SYMBOL_GPL(__devm_regmap_init_sunxi_rsb);
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|
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/* RSB controller driver functions */
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static irqreturn_t sunxi_rsb_irq(int irq, void *dev_id)
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{
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struct sunxi_rsb *rsb = dev_id;
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u32 status;
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status = readl(rsb->regs + RSB_INTS);
|
|
rsb->status = status;
|
|
|
|
/* Clear interrupts */
|
|
status &= (RSB_INTS_LOAD_BSY | RSB_INTS_TRANS_ERR |
|
|
RSB_INTS_TRANS_OVER);
|
|
writel(status, rsb->regs + RSB_INTS);
|
|
|
|
complete(&rsb->complete);
|
|
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
static int sunxi_rsb_init_device_mode(struct sunxi_rsb *rsb)
|
|
{
|
|
int ret = 0;
|
|
u32 reg;
|
|
|
|
/* send init sequence */
|
|
writel(RSB_DMCR_DEVICE_START | RSB_DMCR_MODE_DATA |
|
|
RSB_DMCR_MODE_REG | RSB_DMCR_DEV_ADDR, rsb->regs + RSB_DMCR);
|
|
|
|
readl_poll_timeout(rsb->regs + RSB_DMCR, reg,
|
|
!(reg & RSB_DMCR_DEVICE_START), 100, 250000);
|
|
if (reg & RSB_DMCR_DEVICE_START)
|
|
ret = -ETIMEDOUT;
|
|
|
|
/* clear interrupt status bits */
|
|
writel(readl(rsb->regs + RSB_INTS), rsb->regs + RSB_INTS);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* There are 15 valid runtime addresses, though Allwinner typically
|
|
* skips the first, for unknown reasons, and uses the following three.
|
|
*
|
|
* 0x17, 0x2d, 0x3a, 0x4e, 0x59, 0x63, 0x74, 0x8b,
|
|
* 0x9c, 0xa6, 0xb1, 0xc5, 0xd2, 0xe8, 0xff
|
|
*
|
|
* No designs with 2 RSB slave devices sharing identical hardware
|
|
* addresses on the same bus have been seen in the wild. All designs
|
|
* use 0x2d for the primary PMIC, 0x3a for the secondary PMIC if
|
|
* there is one, and 0x45 for peripheral ICs.
|
|
*
|
|
* The hardware does not seem to support re-setting runtime addresses.
|
|
* Attempts to do so result in the slave devices returning a NACK.
|
|
* Hence we just hardcode the mapping here, like Allwinner does.
|
|
*/
|
|
|
|
static const struct sunxi_rsb_addr_map sunxi_rsb_addr_maps[] = {
|
|
{ 0x3a3, 0x2d }, /* Primary PMIC: AXP223, AXP809, AXP81X, ... */
|
|
{ 0x745, 0x3a }, /* Secondary PMIC: AXP806, ... */
|
|
{ 0xe89, 0x4e }, /* Peripheral IC: AC100, ... */
|
|
};
|
|
|
|
static u8 sunxi_rsb_get_rtaddr(u16 hwaddr)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < ARRAY_SIZE(sunxi_rsb_addr_maps); i++)
|
|
if (hwaddr == sunxi_rsb_addr_maps[i].hwaddr)
|
|
return sunxi_rsb_addr_maps[i].rtaddr;
|
|
|
|
return 0; /* 0 is an invalid runtime address */
|
|
}
|
|
|
|
static int of_rsb_register_devices(struct sunxi_rsb *rsb)
|
|
{
|
|
struct device *dev = rsb->dev;
|
|
struct device_node *child, *np = dev->of_node;
|
|
u32 hwaddr;
|
|
u8 rtaddr;
|
|
int ret;
|
|
|
|
if (!np)
|
|
return -EINVAL;
|
|
|
|
/* Runtime addresses for all slaves should be set first */
|
|
for_each_available_child_of_node(np, child) {
|
|
dev_dbg(dev, "setting child %pOF runtime address\n",
|
|
child);
|
|
|
|
ret = of_property_read_u32(child, "reg", &hwaddr);
|
|
if (ret) {
|
|
dev_err(dev, "%pOF: invalid 'reg' property: %d\n",
|
|
child, ret);
|
|
continue;
|
|
}
|
|
|
|
rtaddr = sunxi_rsb_get_rtaddr(hwaddr);
|
|
if (!rtaddr) {
|
|
dev_err(dev, "%pOF: unknown hardware device address\n",
|
|
child);
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* Since no devices have been registered yet, we are the
|
|
* only ones using the bus, we can skip locking the bus.
|
|
*/
|
|
|
|
/* setup command parameters */
|
|
writel(RSB_CMD_STRA, rsb->regs + RSB_CMD);
|
|
writel(RSB_DAR_RTA(rtaddr) | RSB_DAR_DA(hwaddr),
|
|
rsb->regs + RSB_DAR);
|
|
|
|
/* send command */
|
|
ret = _sunxi_rsb_run_xfer(rsb);
|
|
if (ret)
|
|
dev_warn(dev, "%pOF: set runtime address failed: %d\n",
|
|
child, ret);
|
|
}
|
|
|
|
/* Then we start adding devices and probing them */
|
|
for_each_available_child_of_node(np, child) {
|
|
struct sunxi_rsb_device *rdev;
|
|
|
|
dev_dbg(dev, "adding child %pOF\n", child);
|
|
|
|
ret = of_property_read_u32(child, "reg", &hwaddr);
|
|
if (ret)
|
|
continue;
|
|
|
|
rtaddr = sunxi_rsb_get_rtaddr(hwaddr);
|
|
if (!rtaddr)
|
|
continue;
|
|
|
|
rdev = sunxi_rsb_device_create(rsb, child, hwaddr, rtaddr);
|
|
if (IS_ERR(rdev))
|
|
dev_err(dev, "failed to add child device %pOF: %ld\n",
|
|
child, PTR_ERR(rdev));
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct of_device_id sunxi_rsb_of_match_table[] = {
|
|
{ .compatible = "allwinner,sun8i-a23-rsb" },
|
|
{}
|
|
};
|
|
MODULE_DEVICE_TABLE(of, sunxi_rsb_of_match_table);
|
|
|
|
static int sunxi_rsb_probe(struct platform_device *pdev)
|
|
{
|
|
struct device *dev = &pdev->dev;
|
|
struct device_node *np = dev->of_node;
|
|
struct resource *r;
|
|
struct sunxi_rsb *rsb;
|
|
unsigned long p_clk_freq;
|
|
u32 clk_delay, clk_freq = 3000000;
|
|
int clk_div, irq, ret;
|
|
u32 reg;
|
|
|
|
of_property_read_u32(np, "clock-frequency", &clk_freq);
|
|
if (clk_freq > RSB_MAX_FREQ) {
|
|
dev_err(dev,
|
|
"clock-frequency (%u Hz) is too high (max = 20MHz)\n",
|
|
clk_freq);
|
|
return -EINVAL;
|
|
}
|
|
|
|
rsb = devm_kzalloc(dev, sizeof(*rsb), GFP_KERNEL);
|
|
if (!rsb)
|
|
return -ENOMEM;
|
|
|
|
rsb->dev = dev;
|
|
platform_set_drvdata(pdev, rsb);
|
|
r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
|
|
rsb->regs = devm_ioremap_resource(dev, r);
|
|
if (IS_ERR(rsb->regs))
|
|
return PTR_ERR(rsb->regs);
|
|
|
|
irq = platform_get_irq(pdev, 0);
|
|
if (irq < 0) {
|
|
dev_err(dev, "failed to retrieve irq: %d\n", irq);
|
|
return irq;
|
|
}
|
|
|
|
rsb->clk = devm_clk_get(dev, NULL);
|
|
if (IS_ERR(rsb->clk)) {
|
|
ret = PTR_ERR(rsb->clk);
|
|
dev_err(dev, "failed to retrieve clk: %d\n", ret);
|
|
return ret;
|
|
}
|
|
|
|
ret = clk_prepare_enable(rsb->clk);
|
|
if (ret) {
|
|
dev_err(dev, "failed to enable clk: %d\n", ret);
|
|
return ret;
|
|
}
|
|
|
|
p_clk_freq = clk_get_rate(rsb->clk);
|
|
|
|
rsb->rstc = devm_reset_control_get(dev, NULL);
|
|
if (IS_ERR(rsb->rstc)) {
|
|
ret = PTR_ERR(rsb->rstc);
|
|
dev_err(dev, "failed to retrieve reset controller: %d\n", ret);
|
|
goto err_clk_disable;
|
|
}
|
|
|
|
ret = reset_control_deassert(rsb->rstc);
|
|
if (ret) {
|
|
dev_err(dev, "failed to deassert reset line: %d\n", ret);
|
|
goto err_clk_disable;
|
|
}
|
|
|
|
init_completion(&rsb->complete);
|
|
mutex_init(&rsb->lock);
|
|
|
|
/* reset the controller */
|
|
writel(RSB_CTRL_SOFT_RST, rsb->regs + RSB_CTRL);
|
|
readl_poll_timeout(rsb->regs + RSB_CTRL, reg,
|
|
!(reg & RSB_CTRL_SOFT_RST), 1000, 100000);
|
|
|
|
/*
|
|
* Clock frequency and delay calculation code is from
|
|
* Allwinner U-boot sources.
|
|
*
|
|
* From A83 user manual:
|
|
* bus clock frequency = parent clock frequency / (2 * (divider + 1))
|
|
*/
|
|
clk_div = p_clk_freq / clk_freq / 2;
|
|
if (!clk_div)
|
|
clk_div = 1;
|
|
else if (clk_div > RSB_CCR_MAX_CLK_DIV + 1)
|
|
clk_div = RSB_CCR_MAX_CLK_DIV + 1;
|
|
|
|
clk_delay = clk_div >> 1;
|
|
if (!clk_delay)
|
|
clk_delay = 1;
|
|
|
|
dev_info(dev, "RSB running at %lu Hz\n", p_clk_freq / clk_div / 2);
|
|
writel(RSB_CCR_SDA_OUT_DELAY(clk_delay) | RSB_CCR_CLK_DIV(clk_div - 1),
|
|
rsb->regs + RSB_CCR);
|
|
|
|
ret = devm_request_irq(dev, irq, sunxi_rsb_irq, 0, RSB_CTRL_NAME, rsb);
|
|
if (ret) {
|
|
dev_err(dev, "can't register interrupt handler irq %d: %d\n",
|
|
irq, ret);
|
|
goto err_reset_assert;
|
|
}
|
|
|
|
/* initialize all devices on the bus into RSB mode */
|
|
ret = sunxi_rsb_init_device_mode(rsb);
|
|
if (ret)
|
|
dev_warn(dev, "Initialize device mode failed: %d\n", ret);
|
|
|
|
of_rsb_register_devices(rsb);
|
|
|
|
return 0;
|
|
|
|
err_reset_assert:
|
|
reset_control_assert(rsb->rstc);
|
|
|
|
err_clk_disable:
|
|
clk_disable_unprepare(rsb->clk);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int sunxi_rsb_remove(struct platform_device *pdev)
|
|
{
|
|
struct sunxi_rsb *rsb = platform_get_drvdata(pdev);
|
|
|
|
device_for_each_child(rsb->dev, NULL, sunxi_rsb_remove_devices);
|
|
reset_control_assert(rsb->rstc);
|
|
clk_disable_unprepare(rsb->clk);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct platform_driver sunxi_rsb_driver = {
|
|
.probe = sunxi_rsb_probe,
|
|
.remove = sunxi_rsb_remove,
|
|
.driver = {
|
|
.name = RSB_CTRL_NAME,
|
|
.of_match_table = sunxi_rsb_of_match_table,
|
|
},
|
|
};
|
|
|
|
static int __init sunxi_rsb_init(void)
|
|
{
|
|
int ret;
|
|
|
|
ret = bus_register(&sunxi_rsb_bus);
|
|
if (ret) {
|
|
pr_err("failed to register sunxi sunxi_rsb bus: %d\n", ret);
|
|
return ret;
|
|
}
|
|
|
|
return platform_driver_register(&sunxi_rsb_driver);
|
|
}
|
|
module_init(sunxi_rsb_init);
|
|
|
|
static void __exit sunxi_rsb_exit(void)
|
|
{
|
|
platform_driver_unregister(&sunxi_rsb_driver);
|
|
bus_unregister(&sunxi_rsb_bus);
|
|
}
|
|
module_exit(sunxi_rsb_exit);
|
|
|
|
MODULE_AUTHOR("Chen-Yu Tsai <wens@csie.org>");
|
|
MODULE_DESCRIPTION("Allwinner sunXi Reduced Serial Bus controller driver");
|
|
MODULE_LICENSE("GPL v2");
|