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873 lines
21 KiB
873 lines
21 KiB
/* |
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* RSB (Reduced Serial Bus) driver. |
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* |
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* Author: Chen-Yu Tsai <[email protected]> |
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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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|
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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/pm.h> |
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#include <linux/pm_runtime.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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|
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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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|
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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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|
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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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|
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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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|
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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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|
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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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|
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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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|
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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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|
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#define RSB_MAX_FREQ 20000000 |
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|
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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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u32 clk_freq; |
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}; |
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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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drv->remove(to_sunxi_rsb_device(dev)); |
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return 0; |
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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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|
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kfree(rdev); |
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} |
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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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ret = pm_runtime_resume_and_get(rsb->dev); |
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if (ret) |
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return ret; |
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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) & GENMASK(len * 8 - 1, 0); |
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unlock: |
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mutex_unlock(&rsb->lock); |
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pm_runtime_mark_last_busy(rsb->dev); |
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pm_runtime_put_autosuspend(rsb->dev); |
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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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ret = pm_runtime_resume_and_get(rsb->dev); |
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if (ret) |
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return ret; |
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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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pm_runtime_mark_last_busy(rsb->dev); |
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pm_runtime_put_autosuspend(rsb->dev); |
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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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/* 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); |
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rsb->status = status; |
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/* Clear interrupts */ |
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status &= (RSB_INTS_LOAD_BSY | RSB_INTS_TRANS_ERR | |
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RSB_INTS_TRANS_OVER); |
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writel(status, rsb->regs + RSB_INTS); |
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complete(&rsb->complete); |
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return IRQ_HANDLED; |
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} |
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static int sunxi_rsb_init_device_mode(struct sunxi_rsb *rsb) |
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{ |
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int ret = 0; |
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u32 reg; |
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/* send init sequence */ |
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writel(RSB_DMCR_DEVICE_START | RSB_DMCR_MODE_DATA | |
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RSB_DMCR_MODE_REG | RSB_DMCR_DEV_ADDR, rsb->regs + RSB_DMCR); |
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readl_poll_timeout(rsb->regs + RSB_DMCR, reg, |
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!(reg & RSB_DMCR_DEVICE_START), 100, 250000); |
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if (reg & RSB_DMCR_DEVICE_START) |
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ret = -ETIMEDOUT; |
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/* clear interrupt status bits */ |
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writel(readl(rsb->regs + RSB_INTS), rsb->regs + RSB_INTS); |
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return ret; |
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} |
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|
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/* |
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* There are 15 valid runtime addresses, though Allwinner typically |
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* skips the first, for unknown reasons, and uses the following three. |
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* |
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* 0x17, 0x2d, 0x3a, 0x4e, 0x59, 0x63, 0x74, 0x8b, |
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* 0x9c, 0xa6, 0xb1, 0xc5, 0xd2, 0xe8, 0xff |
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* |
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* No designs with 2 RSB slave devices sharing identical hardware |
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* addresses on the same bus have been seen in the wild. All designs |
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* use 0x2d for the primary PMIC, 0x3a for the secondary PMIC if |
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* there is one, and 0x45 for peripheral ICs. |
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* |
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* The hardware does not seem to support re-setting runtime addresses. |
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* Attempts to do so result in the slave devices returning a NACK. |
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* Hence we just hardcode the mapping here, like Allwinner does. |
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*/ |
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|
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static const struct sunxi_rsb_addr_map sunxi_rsb_addr_maps[] = { |
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{ 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 int sunxi_rsb_hw_init(struct sunxi_rsb *rsb) |
|
{ |
|
struct device *dev = rsb->dev; |
|
unsigned long p_clk_freq; |
|
u32 clk_delay, reg; |
|
int clk_div, ret; |
|
|
|
ret = clk_prepare_enable(rsb->clk); |
|
if (ret) { |
|
dev_err(dev, "failed to enable clk: %d\n", ret); |
|
return ret; |
|
} |
|
|
|
ret = reset_control_deassert(rsb->rstc); |
|
if (ret) { |
|
dev_err(dev, "failed to deassert reset line: %d\n", ret); |
|
goto err_clk_disable; |
|
} |
|
|
|
/* 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)) |
|
*/ |
|
p_clk_freq = clk_get_rate(rsb->clk); |
|
clk_div = p_clk_freq / rsb->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); |
|
|
|
return 0; |
|
|
|
err_clk_disable: |
|
clk_disable_unprepare(rsb->clk); |
|
|
|
return ret; |
|
} |
|
|
|
static void sunxi_rsb_hw_exit(struct sunxi_rsb *rsb) |
|
{ |
|
/* Keep the clock and PM reference counts consistent. */ |
|
if (pm_runtime_status_suspended(rsb->dev)) |
|
pm_runtime_resume(rsb->dev); |
|
reset_control_assert(rsb->rstc); |
|
clk_disable_unprepare(rsb->clk); |
|
} |
|
|
|
static int __maybe_unused sunxi_rsb_runtime_suspend(struct device *dev) |
|
{ |
|
struct sunxi_rsb *rsb = dev_get_drvdata(dev); |
|
|
|
clk_disable_unprepare(rsb->clk); |
|
|
|
return 0; |
|
} |
|
|
|
static int __maybe_unused sunxi_rsb_runtime_resume(struct device *dev) |
|
{ |
|
struct sunxi_rsb *rsb = dev_get_drvdata(dev); |
|
|
|
return clk_prepare_enable(rsb->clk); |
|
} |
|
|
|
static int __maybe_unused sunxi_rsb_suspend(struct device *dev) |
|
{ |
|
struct sunxi_rsb *rsb = dev_get_drvdata(dev); |
|
|
|
sunxi_rsb_hw_exit(rsb); |
|
|
|
return 0; |
|
} |
|
|
|
static int __maybe_unused sunxi_rsb_resume(struct device *dev) |
|
{ |
|
struct sunxi_rsb *rsb = dev_get_drvdata(dev); |
|
|
|
return sunxi_rsb_hw_init(rsb); |
|
} |
|
|
|
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; |
|
u32 clk_freq = 3000000; |
|
int irq, ret; |
|
|
|
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; |
|
rsb->clk_freq = clk_freq; |
|
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) |
|
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; |
|
} |
|
|
|
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); |
|
return ret; |
|
} |
|
|
|
init_completion(&rsb->complete); |
|
mutex_init(&rsb->lock); |
|
|
|
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); |
|
return ret; |
|
} |
|
|
|
ret = sunxi_rsb_hw_init(rsb); |
|
if (ret) |
|
return ret; |
|
|
|
/* 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); |
|
|
|
pm_suspend_ignore_children(dev, true); |
|
pm_runtime_set_active(dev); |
|
pm_runtime_set_autosuspend_delay(dev, MSEC_PER_SEC); |
|
pm_runtime_use_autosuspend(dev); |
|
pm_runtime_enable(dev); |
|
|
|
of_rsb_register_devices(rsb); |
|
|
|
return 0; |
|
} |
|
|
|
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); |
|
pm_runtime_disable(&pdev->dev); |
|
sunxi_rsb_hw_exit(rsb); |
|
|
|
return 0; |
|
} |
|
|
|
static void sunxi_rsb_shutdown(struct platform_device *pdev) |
|
{ |
|
struct sunxi_rsb *rsb = platform_get_drvdata(pdev); |
|
|
|
pm_runtime_disable(&pdev->dev); |
|
sunxi_rsb_hw_exit(rsb); |
|
} |
|
|
|
static const struct dev_pm_ops sunxi_rsb_dev_pm_ops = { |
|
SET_RUNTIME_PM_OPS(sunxi_rsb_runtime_suspend, |
|
sunxi_rsb_runtime_resume, NULL) |
|
SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(sunxi_rsb_suspend, sunxi_rsb_resume) |
|
}; |
|
|
|
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 struct platform_driver sunxi_rsb_driver = { |
|
.probe = sunxi_rsb_probe, |
|
.remove = sunxi_rsb_remove, |
|
.shutdown = sunxi_rsb_shutdown, |
|
.driver = { |
|
.name = RSB_CTRL_NAME, |
|
.of_match_table = sunxi_rsb_of_match_table, |
|
.pm = &sunxi_rsb_dev_pm_ops, |
|
}, |
|
}; |
|
|
|
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 <[email protected]>"); |
|
MODULE_DESCRIPTION("Allwinner sunXi Reduced Serial Bus controller driver"); |
|
MODULE_LICENSE("GPL v2");
|
|
|