| /* |
| * RSB (Reduced Serial Bus) driver. |
| * |
| * Author: Chen-Yu Tsai <wens@csie.org> |
| * |
| * This file is licensed under the terms of the GNU General Public License |
| * version 2. This program is licensed "as is" without any warranty of any |
| * kind, whether express or implied. |
| * |
| * The RSB controller looks like an SMBus controller which only supports |
| * byte and word data transfers. But, it differs from standard SMBus |
| * protocol on several aspects: |
| * - it uses addresses set at runtime to address slaves. Runtime addresses |
| * are sent to slaves using their 12bit hardware addresses. Up to 15 |
| * runtime addresses are available. |
| * - it adds a parity bit every 8bits of data and address for read and |
| * write accesses; this replaces the ack bit |
| * - only one read access is required to read a byte (instead of a write |
| * followed by a read access in standard SMBus protocol) |
| * - there's no Ack bit after each read access |
| * |
| * This means this bus cannot be used to interface with standard SMBus |
| * devices. Devices known to support this interface include the AXP223, |
| * AXP809, and AXP806 PMICs, and the AC100 audio codec, all from X-Powers. |
| * |
| * A description of the operation and wire protocol can be found in the |
| * RSB section of Allwinner's A80 user manual, which can be found at |
| * |
| * https://github.com/allwinner-zh/documents/tree/master/A80 |
| * |
| * This document is officially released by Allwinner. |
| * |
| * This driver is based on i2c-sun6i-p2wi.c, the P2WI bus driver. |
| * |
| */ |
| |
| #include <linux/clk.h> |
| #include <linux/clk/clk-conf.h> |
| #include <linux/device.h> |
| #include <linux/interrupt.h> |
| #include <linux/io.h> |
| #include <linux/iopoll.h> |
| #include <linux/module.h> |
| #include <linux/of.h> |
| #include <linux/of_irq.h> |
| #include <linux/of_platform.h> |
| #include <linux/platform_device.h> |
| #include <linux/regmap.h> |
| #include <linux/reset.h> |
| #include <linux/slab.h> |
| #include <linux/sunxi-rsb.h> |
| #include <linux/types.h> |
| |
| /* RSB registers */ |
| #define RSB_CTRL 0x0 /* Global control */ |
| #define RSB_CCR 0x4 /* Clock control */ |
| #define RSB_INTE 0x8 /* Interrupt controls */ |
| #define RSB_INTS 0xc /* Interrupt status */ |
| #define RSB_ADDR 0x10 /* Address to send with read/write command */ |
| #define RSB_DATA 0x1c /* Data to read/write */ |
| #define RSB_LCR 0x24 /* Line control */ |
| #define RSB_DMCR 0x28 /* Device mode (init) control */ |
| #define RSB_CMD 0x2c /* RSB Command */ |
| #define RSB_DAR 0x30 /* Device address / runtime address */ |
| |
| /* CTRL fields */ |
| #define RSB_CTRL_START_TRANS BIT(7) |
| #define RSB_CTRL_ABORT_TRANS BIT(6) |
| #define RSB_CTRL_GLOBAL_INT_ENB BIT(1) |
| #define RSB_CTRL_SOFT_RST BIT(0) |
| |
| /* CLK CTRL fields */ |
| #define RSB_CCR_SDA_OUT_DELAY(v) (((v) & 0x7) << 8) |
| #define RSB_CCR_MAX_CLK_DIV 0xff |
| #define RSB_CCR_CLK_DIV(v) ((v) & RSB_CCR_MAX_CLK_DIV) |
| |
| /* STATUS fields */ |
| #define RSB_INTS_TRANS_ERR_ACK BIT(16) |
| #define RSB_INTS_TRANS_ERR_DATA_BIT(v) (((v) >> 8) & 0xf) |
| #define RSB_INTS_TRANS_ERR_DATA GENMASK(11, 8) |
| #define RSB_INTS_LOAD_BSY BIT(2) |
| #define RSB_INTS_TRANS_ERR BIT(1) |
| #define RSB_INTS_TRANS_OVER BIT(0) |
| |
| /* LINE CTRL fields*/ |
| #define RSB_LCR_SCL_STATE BIT(5) |
| #define RSB_LCR_SDA_STATE BIT(4) |
| #define RSB_LCR_SCL_CTL BIT(3) |
| #define RSB_LCR_SCL_CTL_EN BIT(2) |
| #define RSB_LCR_SDA_CTL BIT(1) |
| #define RSB_LCR_SDA_CTL_EN BIT(0) |
| |
| /* DEVICE MODE CTRL field values */ |
| #define RSB_DMCR_DEVICE_START BIT(31) |
| #define RSB_DMCR_MODE_DATA (0x7c << 16) |
| #define RSB_DMCR_MODE_REG (0x3e << 8) |
| #define RSB_DMCR_DEV_ADDR 0x00 |
| |
| /* CMD values */ |
| #define RSB_CMD_RD8 0x8b |
| #define RSB_CMD_RD16 0x9c |
| #define RSB_CMD_RD32 0xa6 |
| #define RSB_CMD_WR8 0x4e |
| #define RSB_CMD_WR16 0x59 |
| #define RSB_CMD_WR32 0x63 |
| #define RSB_CMD_STRA 0xe8 |
| |
| /* DAR fields */ |
| #define RSB_DAR_RTA(v) (((v) & 0xff) << 16) |
| #define RSB_DAR_DA(v) ((v) & 0xffff) |
| |
| #define RSB_MAX_FREQ 20000000 |
| |
| #define RSB_CTRL_NAME "sunxi-rsb" |
| |
| struct sunxi_rsb_addr_map { |
| u16 hwaddr; |
| u8 rtaddr; |
| }; |
| |
| struct sunxi_rsb { |
| struct device *dev; |
| void __iomem *regs; |
| struct clk *clk; |
| struct reset_control *rstc; |
| struct completion complete; |
| struct mutex lock; |
| unsigned int status; |
| }; |
| |
| /* bus / slave device related functions */ |
| static struct bus_type sunxi_rsb_bus; |
| |
| static int sunxi_rsb_device_match(struct device *dev, struct device_driver *drv) |
| { |
| return of_driver_match_device(dev, drv); |
| } |
| |
| static int sunxi_rsb_device_probe(struct device *dev) |
| { |
| const struct sunxi_rsb_driver *drv = to_sunxi_rsb_driver(dev->driver); |
| struct sunxi_rsb_device *rdev = to_sunxi_rsb_device(dev); |
| int ret; |
| |
| if (!drv->probe) |
| return -ENODEV; |
| |
| if (!rdev->irq) { |
| int irq = -ENOENT; |
| |
| if (dev->of_node) |
| irq = of_irq_get(dev->of_node, 0); |
| |
| if (irq == -EPROBE_DEFER) |
| return irq; |
| if (irq < 0) |
| irq = 0; |
| |
| rdev->irq = irq; |
| } |
| |
| ret = of_clk_set_defaults(dev->of_node, false); |
| if (ret < 0) |
| return ret; |
| |
| return drv->probe(rdev); |
| } |
| |
| static int sunxi_rsb_device_remove(struct device *dev) |
| { |
| const struct sunxi_rsb_driver *drv = to_sunxi_rsb_driver(dev->driver); |
| |
| return drv->remove(to_sunxi_rsb_device(dev)); |
| } |
| |
| static struct bus_type sunxi_rsb_bus = { |
| .name = RSB_CTRL_NAME, |
| .match = sunxi_rsb_device_match, |
| .probe = sunxi_rsb_device_probe, |
| .remove = sunxi_rsb_device_remove, |
| .uevent = of_device_uevent_modalias, |
| }; |
| |
| static void sunxi_rsb_dev_release(struct device *dev) |
| { |
| struct sunxi_rsb_device *rdev = to_sunxi_rsb_device(dev); |
| |
| kfree(rdev); |
| } |
| |
| /** |
| * sunxi_rsb_device_create() - allocate and add an RSB device |
| * @rsb: RSB controller |
| * @node: RSB slave device node |
| * @hwaddr: RSB slave hardware address |
| * @rtaddr: RSB slave runtime address |
| */ |
| static struct sunxi_rsb_device *sunxi_rsb_device_create(struct sunxi_rsb *rsb, |
| struct device_node *node, u16 hwaddr, u8 rtaddr) |
| { |
| int err; |
| struct sunxi_rsb_device *rdev; |
| |
| rdev = kzalloc(sizeof(*rdev), GFP_KERNEL); |
| if (!rdev) |
| return ERR_PTR(-ENOMEM); |
| |
| rdev->rsb = rsb; |
| rdev->hwaddr = hwaddr; |
| rdev->rtaddr = rtaddr; |
| rdev->dev.bus = &sunxi_rsb_bus; |
| rdev->dev.parent = rsb->dev; |
| rdev->dev.of_node = node; |
| rdev->dev.release = sunxi_rsb_dev_release; |
| |
| dev_set_name(&rdev->dev, "%s-%x", RSB_CTRL_NAME, hwaddr); |
| |
| err = device_register(&rdev->dev); |
| if (err < 0) { |
| dev_err(&rdev->dev, "Can't add %s, status %d\n", |
| dev_name(&rdev->dev), err); |
| goto err_device_add; |
| } |
| |
| dev_dbg(&rdev->dev, "device %s registered\n", dev_name(&rdev->dev)); |
| |
| err_device_add: |
| put_device(&rdev->dev); |
| |
| return ERR_PTR(err); |
| } |
| |
| /** |
| * sunxi_rsb_device_unregister(): unregister an RSB device |
| * @rdev: rsb_device to be removed |
| */ |
| static void sunxi_rsb_device_unregister(struct sunxi_rsb_device *rdev) |
| { |
| device_unregister(&rdev->dev); |
| } |
| |
| static int sunxi_rsb_remove_devices(struct device *dev, void *data) |
| { |
| struct sunxi_rsb_device *rdev = to_sunxi_rsb_device(dev); |
| |
| if (dev->bus == &sunxi_rsb_bus) |
| sunxi_rsb_device_unregister(rdev); |
| |
| return 0; |
| } |
| |
| /** |
| * sunxi_rsb_driver_register() - Register device driver with RSB core |
| * @rdrv: device driver to be associated with slave-device. |
| * |
| * This API will register the client driver with the RSB framework. |
| * It is typically called from the driver's module-init function. |
| */ |
| int sunxi_rsb_driver_register(struct sunxi_rsb_driver *rdrv) |
| { |
| rdrv->driver.bus = &sunxi_rsb_bus; |
| return driver_register(&rdrv->driver); |
| } |
| EXPORT_SYMBOL_GPL(sunxi_rsb_driver_register); |
| |
| /* common code that starts a transfer */ |
| static int _sunxi_rsb_run_xfer(struct sunxi_rsb *rsb) |
| { |
| if (readl(rsb->regs + RSB_CTRL) & RSB_CTRL_START_TRANS) { |
| dev_dbg(rsb->dev, "RSB transfer still in progress\n"); |
| return -EBUSY; |
| } |
| |
| reinit_completion(&rsb->complete); |
| |
| writel(RSB_INTS_LOAD_BSY | RSB_INTS_TRANS_ERR | RSB_INTS_TRANS_OVER, |
| rsb->regs + RSB_INTE); |
| writel(RSB_CTRL_START_TRANS | RSB_CTRL_GLOBAL_INT_ENB, |
| rsb->regs + RSB_CTRL); |
| |
| if (!wait_for_completion_io_timeout(&rsb->complete, |
| msecs_to_jiffies(100))) { |
| dev_dbg(rsb->dev, "RSB timeout\n"); |
| |
| /* abort the transfer */ |
| writel(RSB_CTRL_ABORT_TRANS, rsb->regs + RSB_CTRL); |
| |
| /* clear any interrupt flags */ |
| writel(readl(rsb->regs + RSB_INTS), rsb->regs + RSB_INTS); |
| |
| return -ETIMEDOUT; |
| } |
| |
| if (rsb->status & RSB_INTS_LOAD_BSY) { |
| dev_dbg(rsb->dev, "RSB busy\n"); |
| return -EBUSY; |
| } |
| |
| if (rsb->status & RSB_INTS_TRANS_ERR) { |
| if (rsb->status & RSB_INTS_TRANS_ERR_ACK) { |
| dev_dbg(rsb->dev, "RSB slave nack\n"); |
| return -EINVAL; |
| } |
| |
| if (rsb->status & RSB_INTS_TRANS_ERR_DATA) { |
| dev_dbg(rsb->dev, "RSB transfer data error\n"); |
| return -EIO; |
| } |
| } |
| |
| return 0; |
| } |
| |
| static int sunxi_rsb_read(struct sunxi_rsb *rsb, u8 rtaddr, u8 addr, |
| u32 *buf, size_t len) |
| { |
| u32 cmd; |
| int ret; |
| |
| if (!buf) |
| return -EINVAL; |
| |
| switch (len) { |
| case 1: |
| cmd = RSB_CMD_RD8; |
| break; |
| case 2: |
| cmd = RSB_CMD_RD16; |
| break; |
| case 4: |
| cmd = RSB_CMD_RD32; |
| break; |
| default: |
| dev_err(rsb->dev, "Invalid access width: %zd\n", len); |
| return -EINVAL; |
| } |
| |
| mutex_lock(&rsb->lock); |
| |
| writel(addr, rsb->regs + RSB_ADDR); |
| writel(RSB_DAR_RTA(rtaddr), rsb->regs + RSB_DAR); |
| writel(cmd, rsb->regs + RSB_CMD); |
| |
| ret = _sunxi_rsb_run_xfer(rsb); |
| if (ret) |
| goto unlock; |
| |
| *buf = readl(rsb->regs + RSB_DATA); |
| |
| unlock: |
| mutex_unlock(&rsb->lock); |
| |
| return ret; |
| } |
| |
| static int sunxi_rsb_write(struct sunxi_rsb *rsb, u8 rtaddr, u8 addr, |
| const u32 *buf, size_t len) |
| { |
| u32 cmd; |
| int ret; |
| |
| if (!buf) |
| return -EINVAL; |
| |
| switch (len) { |
| case 1: |
| cmd = RSB_CMD_WR8; |
| break; |
| case 2: |
| cmd = RSB_CMD_WR16; |
| break; |
| case 4: |
| cmd = RSB_CMD_WR32; |
| break; |
| default: |
| dev_err(rsb->dev, "Invalid access width: %zd\n", len); |
| return -EINVAL; |
| } |
| |
| mutex_lock(&rsb->lock); |
| |
| writel(addr, rsb->regs + RSB_ADDR); |
| writel(RSB_DAR_RTA(rtaddr), rsb->regs + RSB_DAR); |
| writel(*buf, rsb->regs + RSB_DATA); |
| writel(cmd, rsb->regs + RSB_CMD); |
| ret = _sunxi_rsb_run_xfer(rsb); |
| |
| mutex_unlock(&rsb->lock); |
| |
| return ret; |
| } |
| |
| /* RSB regmap functions */ |
| struct sunxi_rsb_ctx { |
| struct sunxi_rsb_device *rdev; |
| int size; |
| }; |
| |
| static int regmap_sunxi_rsb_reg_read(void *context, unsigned int reg, |
| unsigned int *val) |
| { |
| struct sunxi_rsb_ctx *ctx = context; |
| struct sunxi_rsb_device *rdev = ctx->rdev; |
| |
| if (reg > 0xff) |
| return -EINVAL; |
| |
| return sunxi_rsb_read(rdev->rsb, rdev->rtaddr, reg, val, ctx->size); |
| } |
| |
| static int regmap_sunxi_rsb_reg_write(void *context, unsigned int reg, |
| unsigned int val) |
| { |
| struct sunxi_rsb_ctx *ctx = context; |
| struct sunxi_rsb_device *rdev = ctx->rdev; |
| |
| return sunxi_rsb_write(rdev->rsb, rdev->rtaddr, reg, &val, ctx->size); |
| } |
| |
| static void regmap_sunxi_rsb_free_ctx(void *context) |
| { |
| struct sunxi_rsb_ctx *ctx = context; |
| |
| kfree(ctx); |
| } |
| |
| static struct regmap_bus regmap_sunxi_rsb = { |
| .reg_write = regmap_sunxi_rsb_reg_write, |
| .reg_read = regmap_sunxi_rsb_reg_read, |
| .free_context = regmap_sunxi_rsb_free_ctx, |
| .reg_format_endian_default = REGMAP_ENDIAN_NATIVE, |
| .val_format_endian_default = REGMAP_ENDIAN_NATIVE, |
| }; |
| |
| static struct sunxi_rsb_ctx *regmap_sunxi_rsb_init_ctx(struct sunxi_rsb_device *rdev, |
| const struct regmap_config *config) |
| { |
| struct sunxi_rsb_ctx *ctx; |
| |
| switch (config->val_bits) { |
| case 8: |
| case 16: |
| case 32: |
| break; |
| default: |
| return ERR_PTR(-EINVAL); |
| } |
| |
| ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); |
| if (!ctx) |
| return ERR_PTR(-ENOMEM); |
| |
| ctx->rdev = rdev; |
| ctx->size = config->val_bits / 8; |
| |
| return ctx; |
| } |
| |
| struct regmap *__devm_regmap_init_sunxi_rsb(struct sunxi_rsb_device *rdev, |
| const struct regmap_config *config, |
| struct lock_class_key *lock_key, |
| const char *lock_name) |
| { |
| struct sunxi_rsb_ctx *ctx = regmap_sunxi_rsb_init_ctx(rdev, config); |
| |
| if (IS_ERR(ctx)) |
| return ERR_CAST(ctx); |
| |
| return __devm_regmap_init(&rdev->dev, ®map_sunxi_rsb, ctx, config, |
| lock_key, lock_name); |
| } |
| EXPORT_SYMBOL_GPL(__devm_regmap_init_sunxi_rsb); |
| |
| /* RSB controller driver functions */ |
| static irqreturn_t sunxi_rsb_irq(int irq, void *dev_id) |
| { |
| struct sunxi_rsb *rsb = dev_id; |
| u32 status; |
| |
| 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"); |