| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Boris Brezillon | 1398 | 99.71% | 2 | 33.33% |
| Wolfram Sang | 1 | 0.07% | 1 | 16.67% |
| Andy Shevchenko | 1 | 0.07% | 1 | 16.67% |
| Philipp Zabel | 1 | 0.07% | 1 | 16.67% |
| Rob Herring | 1 | 0.07% | 1 | 16.67% |
| Total | 1402 | 6 |
/* * P2WI (Push-Pull Two Wire Interface) bus driver. * * Author: Boris BREZILLON <boris.brezillon@free-electrons.com> * * 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 P2WI controller looks like an SMBus controller which only supports byte * data transfers. But, it differs from standard SMBus protocol on several * aspects: * - it supports only one slave device, and thus drop the address field * - it adds a parity bit every 8bits of data * - 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 byte transfer * * This means this bus cannot be used to interface with standard SMBus * devices (the only known device to support this interface is the AXP221 * PMIC). * */ #include <linux/clk.h> #include <linux/i2c.h> #include <linux/io.h> #include <linux/interrupt.h> #include <linux/module.h> #include <linux/of.h> #include <linux/platform_device.h> #include <linux/reset.h> /* P2WI registers */ #define P2WI_CTRL 0x0 #define P2WI_CCR 0x4 #define P2WI_INTE 0x8 #define P2WI_INTS 0xc #define P2WI_DADDR0 0x10 #define P2WI_DADDR1 0x14 #define P2WI_DLEN 0x18 #define P2WI_DATA0 0x1c #define P2WI_DATA1 0x20 #define P2WI_LCR 0x24 #define P2WI_PMCR 0x28 /* CTRL fields */ #define P2WI_CTRL_START_TRANS BIT(7) #define P2WI_CTRL_ABORT_TRANS BIT(6) #define P2WI_CTRL_GLOBAL_INT_ENB BIT(1) #define P2WI_CTRL_SOFT_RST BIT(0) /* CLK CTRL fields */ #define P2WI_CCR_SDA_OUT_DELAY(v) (((v) & 0x7) << 8) #define P2WI_CCR_MAX_CLK_DIV 0xff #define P2WI_CCR_CLK_DIV(v) ((v) & P2WI_CCR_MAX_CLK_DIV) /* STATUS fields */ #define P2WI_INTS_TRANS_ERR_ID(v) (((v) >> 8) & 0xff) #define P2WI_INTS_LOAD_BSY BIT(2) #define P2WI_INTS_TRANS_ERR BIT(1) #define P2WI_INTS_TRANS_OVER BIT(0) /* DATA LENGTH fields*/ #define P2WI_DLEN_READ BIT(4) #define P2WI_DLEN_DATA_LENGTH(v) ((v - 1) & 0x7) /* LINE CTRL fields*/ #define P2WI_LCR_SCL_STATE BIT(5) #define P2WI_LCR_SDA_STATE BIT(4) #define P2WI_LCR_SCL_CTL BIT(3) #define P2WI_LCR_SCL_CTL_EN BIT(2) #define P2WI_LCR_SDA_CTL BIT(1) #define P2WI_LCR_SDA_CTL_EN BIT(0) /* PMU MODE CTRL fields */ #define P2WI_PMCR_PMU_INIT_SEND BIT(31) #define P2WI_PMCR_PMU_INIT_DATA(v) (((v) & 0xff) << 16) #define P2WI_PMCR_PMU_MODE_REG(v) (((v) & 0xff) << 8) #define P2WI_PMCR_PMU_DEV_ADDR(v) ((v) & 0xff) #define P2WI_MAX_FREQ 6000000 struct p2wi { struct i2c_adapter adapter; struct completion complete; unsigned int status; void __iomem *regs; struct clk *clk; struct reset_control *rstc; int slave_addr; }; static irqreturn_t p2wi_interrupt(int irq, void *dev_id) { struct p2wi *p2wi = dev_id; unsigned long status; status = readl(p2wi->regs + P2WI_INTS); p2wi->status = status; /* Clear interrupts */ status &= (P2WI_INTS_LOAD_BSY | P2WI_INTS_TRANS_ERR | P2WI_INTS_TRANS_OVER); writel(status, p2wi->regs + P2WI_INTS); complete(&p2wi->complete); return IRQ_HANDLED; } static u32 p2wi_functionality(struct i2c_adapter *adap) { return I2C_FUNC_SMBUS_BYTE_DATA; } static int p2wi_smbus_xfer(struct i2c_adapter *adap, u16 addr, unsigned short flags, char read_write, u8 command, int size, union i2c_smbus_data *data) { struct p2wi *p2wi = i2c_get_adapdata(adap); unsigned long dlen = P2WI_DLEN_DATA_LENGTH(1); if (p2wi->slave_addr >= 0 && addr != p2wi->slave_addr) { dev_err(&adap->dev, "invalid P2WI address\n"); return -EINVAL; } if (!data) return -EINVAL; writel(command, p2wi->regs + P2WI_DADDR0); if (read_write == I2C_SMBUS_READ) dlen |= P2WI_DLEN_READ; else writel(data->byte, p2wi->regs + P2WI_DATA0); writel(dlen, p2wi->regs + P2WI_DLEN); if (readl(p2wi->regs + P2WI_CTRL) & P2WI_CTRL_START_TRANS) { dev_err(&adap->dev, "P2WI bus busy\n"); return -EBUSY; } reinit_completion(&p2wi->complete); writel(P2WI_INTS_LOAD_BSY | P2WI_INTS_TRANS_ERR | P2WI_INTS_TRANS_OVER, p2wi->regs + P2WI_INTE); writel(P2WI_CTRL_START_TRANS | P2WI_CTRL_GLOBAL_INT_ENB, p2wi->regs + P2WI_CTRL); wait_for_completion(&p2wi->complete); if (p2wi->status & P2WI_INTS_LOAD_BSY) { dev_err(&adap->dev, "P2WI bus busy\n"); return -EBUSY; } if (p2wi->status & P2WI_INTS_TRANS_ERR) { dev_err(&adap->dev, "P2WI bus xfer error\n"); return -ENXIO; } if (read_write == I2C_SMBUS_READ) data->byte = readl(p2wi->regs + P2WI_DATA0); return 0; } static const struct i2c_algorithm p2wi_algo = { .smbus_xfer = p2wi_smbus_xfer, .functionality = p2wi_functionality, }; static const struct of_device_id p2wi_of_match_table[] = { { .compatible = "allwinner,sun6i-a31-p2wi" }, {} }; MODULE_DEVICE_TABLE(of, p2wi_of_match_table); static int p2wi_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct device_node *np = dev->of_node; struct device_node *childnp; unsigned long parent_clk_freq; u32 clk_freq = I2C_MAX_STANDARD_MODE_FREQ; struct resource *r; struct p2wi *p2wi; u32 slave_addr; int clk_div; int irq; int ret; of_property_read_u32(np, "clock-frequency", &clk_freq); if (clk_freq > P2WI_MAX_FREQ) { dev_err(dev, "required clock-frequency (%u Hz) is too high (max = 6MHz)", clk_freq); return -EINVAL; } if (of_get_child_count(np) > 1) { dev_err(dev, "P2WI only supports one slave device\n"); return -EINVAL; } p2wi = devm_kzalloc(dev, sizeof(struct p2wi), GFP_KERNEL); if (!p2wi) return -ENOMEM; p2wi->slave_addr = -1; /* * Authorize a p2wi node without any children to be able to use an * i2c-dev from userpace. * In this case the slave_addr is set to -1 and won't be checked when * launching a P2WI transfer. */ childnp = of_get_next_available_child(np, NULL); if (childnp) { ret = of_property_read_u32(childnp, "reg", &slave_addr); if (ret) { dev_err(dev, "invalid slave address on node %pOF\n", childnp); return -EINVAL; } p2wi->slave_addr = slave_addr; } r = platform_get_resource(pdev, IORESOURCE_MEM, 0); p2wi->regs = devm_ioremap_resource(dev, r); if (IS_ERR(p2wi->regs)) return PTR_ERR(p2wi->regs); strlcpy(p2wi->adapter.name, pdev->name, sizeof(p2wi->adapter.name)); irq = platform_get_irq(pdev, 0); if (irq < 0) { dev_err(dev, "failed to retrieve irq: %d\n", irq); return irq; } p2wi->clk = devm_clk_get(dev, NULL); if (IS_ERR(p2wi->clk)) { ret = PTR_ERR(p2wi->clk); dev_err(dev, "failed to retrieve clk: %d\n", ret); return ret; } ret = clk_prepare_enable(p2wi->clk); if (ret) { dev_err(dev, "failed to enable clk: %d\n", ret); return ret; } parent_clk_freq = clk_get_rate(p2wi->clk); p2wi->rstc = devm_reset_control_get_exclusive(dev, NULL); if (IS_ERR(p2wi->rstc)) { ret = PTR_ERR(p2wi->rstc); dev_err(dev, "failed to retrieve reset controller: %d\n", ret); goto err_clk_disable; } ret = reset_control_deassert(p2wi->rstc); if (ret) { dev_err(dev, "failed to deassert reset line: %d\n", ret); goto err_clk_disable; } init_completion(&p2wi->complete); p2wi->adapter.dev.parent = dev; p2wi->adapter.algo = &p2wi_algo; p2wi->adapter.owner = THIS_MODULE; p2wi->adapter.dev.of_node = pdev->dev.of_node; platform_set_drvdata(pdev, p2wi); i2c_set_adapdata(&p2wi->adapter, p2wi); ret = devm_request_irq(dev, irq, p2wi_interrupt, 0, pdev->name, p2wi); if (ret) { dev_err(dev, "can't register interrupt handler irq%d: %d\n", irq, ret); goto err_reset_assert; } writel(P2WI_CTRL_SOFT_RST, p2wi->regs + P2WI_CTRL); clk_div = parent_clk_freq / clk_freq; if (!clk_div) { dev_warn(dev, "clock-frequency is too high, setting it to %lu Hz\n", parent_clk_freq); clk_div = 1; } else if (clk_div > P2WI_CCR_MAX_CLK_DIV) { dev_warn(dev, "clock-frequency is too low, setting it to %lu Hz\n", parent_clk_freq / P2WI_CCR_MAX_CLK_DIV); clk_div = P2WI_CCR_MAX_CLK_DIV; } writel(P2WI_CCR_SDA_OUT_DELAY(1) | P2WI_CCR_CLK_DIV(clk_div), p2wi->regs + P2WI_CCR); ret = i2c_add_adapter(&p2wi->adapter); if (!ret) return 0; err_reset_assert: reset_control_assert(p2wi->rstc); err_clk_disable: clk_disable_unprepare(p2wi->clk); return ret; } static int p2wi_remove(struct platform_device *dev) { struct p2wi *p2wi = platform_get_drvdata(dev); reset_control_assert(p2wi->rstc); clk_disable_unprepare(p2wi->clk); i2c_del_adapter(&p2wi->adapter); return 0; } static struct platform_driver p2wi_driver = { .probe = p2wi_probe, .remove = p2wi_remove, .driver = { .name = "i2c-sunxi-p2wi", .of_match_table = p2wi_of_match_table, }, }; module_platform_driver(p2wi_driver); MODULE_AUTHOR("Boris BREZILLON <boris.brezillon@free-electrons.com>"); MODULE_DESCRIPTION("Allwinner P2WI driver"); MODULE_LICENSE("GPL v2");
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