| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Tony Prisk | 2168 | 99.04% | 1 | 12.50% |
| Nicholas Mc Guire | 12 | 0.55% | 2 | 25.00% |
| Wolfram Sang | 5 | 0.23% | 2 | 25.00% |
| Thomas Gleixner | 2 | 0.09% | 1 | 12.50% |
| Andy Shevchenko | 1 | 0.05% | 1 | 12.50% |
| Jingoo Han | 1 | 0.05% | 1 | 12.50% |
| Total | 2189 | 8 |
// SPDX-License-Identifier: GPL-2.0-or-later /* * Wondermedia I2C Master Mode Driver * * Copyright (C) 2012 Tony Prisk <linux@prisktech.co.nz> * * Derived from GPLv2+ licensed source: * - Copyright (C) 2008 WonderMedia Technologies, Inc. */ #include <linux/clk.h> #include <linux/delay.h> #include <linux/err.h> #include <linux/i2c.h> #include <linux/interrupt.h> #include <linux/io.h> #include <linux/module.h> #include <linux/of.h> #include <linux/of_address.h> #include <linux/of_irq.h> #include <linux/platform_device.h> #define REG_CR 0x00 #define REG_TCR 0x02 #define REG_CSR 0x04 #define REG_ISR 0x06 #define REG_IMR 0x08 #define REG_CDR 0x0A #define REG_TR 0x0C #define REG_MCR 0x0E #define REG_SLAVE_CR 0x10 #define REG_SLAVE_SR 0x12 #define REG_SLAVE_ISR 0x14 #define REG_SLAVE_IMR 0x16 #define REG_SLAVE_DR 0x18 #define REG_SLAVE_TR 0x1A /* REG_CR Bit fields */ #define CR_TX_NEXT_ACK 0x0000 #define CR_ENABLE 0x0001 #define CR_TX_NEXT_NO_ACK 0x0002 #define CR_TX_END 0x0004 #define CR_CPU_RDY 0x0008 #define SLAV_MODE_SEL 0x8000 /* REG_TCR Bit fields */ #define TCR_STANDARD_MODE 0x0000 #define TCR_MASTER_WRITE 0x0000 #define TCR_HS_MODE 0x2000 #define TCR_MASTER_READ 0x4000 #define TCR_FAST_MODE 0x8000 #define TCR_SLAVE_ADDR_MASK 0x007F /* REG_ISR Bit fields */ #define ISR_NACK_ADDR 0x0001 #define ISR_BYTE_END 0x0002 #define ISR_SCL_TIMEOUT 0x0004 #define ISR_WRITE_ALL 0x0007 /* REG_IMR Bit fields */ #define IMR_ENABLE_ALL 0x0007 /* REG_CSR Bit fields */ #define CSR_RCV_NOT_ACK 0x0001 #define CSR_RCV_ACK_MASK 0x0001 #define CSR_READY_MASK 0x0002 /* REG_TR */ #define SCL_TIMEOUT(x) (((x) & 0xFF) << 8) #define TR_STD 0x0064 #define TR_HS 0x0019 /* REG_MCR */ #define MCR_APB_96M 7 #define MCR_APB_166M 12 #define I2C_MODE_STANDARD 0 #define I2C_MODE_FAST 1 #define WMT_I2C_TIMEOUT (msecs_to_jiffies(1000)) struct wmt_i2c_dev { struct i2c_adapter adapter; struct completion complete; struct device *dev; void __iomem *base; struct clk *clk; int mode; int irq; u16 cmd_status; }; static int wmt_i2c_wait_bus_not_busy(struct wmt_i2c_dev *i2c_dev) { unsigned long timeout; timeout = jiffies + WMT_I2C_TIMEOUT; while (!(readw(i2c_dev->base + REG_CSR) & CSR_READY_MASK)) { if (time_after(jiffies, timeout)) { dev_warn(i2c_dev->dev, "timeout waiting for bus ready\n"); return -EBUSY; } msleep(20); } return 0; } static int wmt_check_status(struct wmt_i2c_dev *i2c_dev) { int ret = 0; if (i2c_dev->cmd_status & ISR_NACK_ADDR) ret = -EIO; if (i2c_dev->cmd_status & ISR_SCL_TIMEOUT) ret = -ETIMEDOUT; return ret; } static int wmt_i2c_write(struct i2c_adapter *adap, struct i2c_msg *pmsg, int last) { struct wmt_i2c_dev *i2c_dev = i2c_get_adapdata(adap); u16 val, tcr_val; int ret; unsigned long wait_result; int xfer_len = 0; if (!(pmsg->flags & I2C_M_NOSTART)) { ret = wmt_i2c_wait_bus_not_busy(i2c_dev); if (ret < 0) return ret; } if (pmsg->len == 0) { /* * We still need to run through the while (..) once, so * start at -1 and break out early from the loop */ xfer_len = -1; writew(0, i2c_dev->base + REG_CDR); } else { writew(pmsg->buf[0] & 0xFF, i2c_dev->base + REG_CDR); } if (!(pmsg->flags & I2C_M_NOSTART)) { val = readw(i2c_dev->base + REG_CR); val &= ~CR_TX_END; writew(val, i2c_dev->base + REG_CR); val = readw(i2c_dev->base + REG_CR); val |= CR_CPU_RDY; writew(val, i2c_dev->base + REG_CR); } reinit_completion(&i2c_dev->complete); if (i2c_dev->mode == I2C_MODE_STANDARD) tcr_val = TCR_STANDARD_MODE; else tcr_val = TCR_FAST_MODE; tcr_val |= (TCR_MASTER_WRITE | (pmsg->addr & TCR_SLAVE_ADDR_MASK)); writew(tcr_val, i2c_dev->base + REG_TCR); if (pmsg->flags & I2C_M_NOSTART) { val = readw(i2c_dev->base + REG_CR); val |= CR_CPU_RDY; writew(val, i2c_dev->base + REG_CR); } while (xfer_len < pmsg->len) { wait_result = wait_for_completion_timeout(&i2c_dev->complete, msecs_to_jiffies(500)); if (wait_result == 0) return -ETIMEDOUT; ret = wmt_check_status(i2c_dev); if (ret) return ret; xfer_len++; val = readw(i2c_dev->base + REG_CSR); if ((val & CSR_RCV_ACK_MASK) == CSR_RCV_NOT_ACK) { dev_dbg(i2c_dev->dev, "write RCV NACK error\n"); return -EIO; } if (pmsg->len == 0) { val = CR_TX_END | CR_CPU_RDY | CR_ENABLE; writew(val, i2c_dev->base + REG_CR); break; } if (xfer_len == pmsg->len) { if (last != 1) writew(CR_ENABLE, i2c_dev->base + REG_CR); } else { writew(pmsg->buf[xfer_len] & 0xFF, i2c_dev->base + REG_CDR); writew(CR_CPU_RDY | CR_ENABLE, i2c_dev->base + REG_CR); } } return 0; } static int wmt_i2c_read(struct i2c_adapter *adap, struct i2c_msg *pmsg, int last) { struct wmt_i2c_dev *i2c_dev = i2c_get_adapdata(adap); u16 val, tcr_val; int ret; unsigned long wait_result; u32 xfer_len = 0; if (!(pmsg->flags & I2C_M_NOSTART)) { ret = wmt_i2c_wait_bus_not_busy(i2c_dev); if (ret < 0) return ret; } val = readw(i2c_dev->base + REG_CR); val &= ~CR_TX_END; writew(val, i2c_dev->base + REG_CR); val = readw(i2c_dev->base + REG_CR); val &= ~CR_TX_NEXT_NO_ACK; writew(val, i2c_dev->base + REG_CR); if (!(pmsg->flags & I2C_M_NOSTART)) { val = readw(i2c_dev->base + REG_CR); val |= CR_CPU_RDY; writew(val, i2c_dev->base + REG_CR); } if (pmsg->len == 1) { val = readw(i2c_dev->base + REG_CR); val |= CR_TX_NEXT_NO_ACK; writew(val, i2c_dev->base + REG_CR); } reinit_completion(&i2c_dev->complete); if (i2c_dev->mode == I2C_MODE_STANDARD) tcr_val = TCR_STANDARD_MODE; else tcr_val = TCR_FAST_MODE; tcr_val |= TCR_MASTER_READ | (pmsg->addr & TCR_SLAVE_ADDR_MASK); writew(tcr_val, i2c_dev->base + REG_TCR); if (pmsg->flags & I2C_M_NOSTART) { val = readw(i2c_dev->base + REG_CR); val |= CR_CPU_RDY; writew(val, i2c_dev->base + REG_CR); } while (xfer_len < pmsg->len) { wait_result = wait_for_completion_timeout(&i2c_dev->complete, msecs_to_jiffies(500)); if (!wait_result) return -ETIMEDOUT; ret = wmt_check_status(i2c_dev); if (ret) return ret; pmsg->buf[xfer_len] = readw(i2c_dev->base + REG_CDR) >> 8; xfer_len++; if (xfer_len == pmsg->len - 1) { val = readw(i2c_dev->base + REG_CR); val |= (CR_TX_NEXT_NO_ACK | CR_CPU_RDY); writew(val, i2c_dev->base + REG_CR); } else { val = readw(i2c_dev->base + REG_CR); val |= CR_CPU_RDY; writew(val, i2c_dev->base + REG_CR); } } return 0; } static int wmt_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) { struct i2c_msg *pmsg; int i, is_last; int ret = 0; for (i = 0; ret >= 0 && i < num; i++) { is_last = ((i + 1) == num); pmsg = &msgs[i]; if (pmsg->flags & I2C_M_RD) ret = wmt_i2c_read(adap, pmsg, is_last); else ret = wmt_i2c_write(adap, pmsg, is_last); } return (ret < 0) ? ret : i; } static u32 wmt_i2c_func(struct i2c_adapter *adap) { return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_NOSTART; } static const struct i2c_algorithm wmt_i2c_algo = { .master_xfer = wmt_i2c_xfer, .functionality = wmt_i2c_func, }; static irqreturn_t wmt_i2c_isr(int irq, void *data) { struct wmt_i2c_dev *i2c_dev = data; /* save the status and write-clear it */ i2c_dev->cmd_status = readw(i2c_dev->base + REG_ISR); writew(i2c_dev->cmd_status, i2c_dev->base + REG_ISR); complete(&i2c_dev->complete); return IRQ_HANDLED; } static int wmt_i2c_reset_hardware(struct wmt_i2c_dev *i2c_dev) { int err; err = clk_prepare_enable(i2c_dev->clk); if (err) { dev_err(i2c_dev->dev, "failed to enable clock\n"); return err; } err = clk_set_rate(i2c_dev->clk, 20000000); if (err) { dev_err(i2c_dev->dev, "failed to set clock = 20Mhz\n"); clk_disable_unprepare(i2c_dev->clk); return err; } writew(0, i2c_dev->base + REG_CR); writew(MCR_APB_166M, i2c_dev->base + REG_MCR); writew(ISR_WRITE_ALL, i2c_dev->base + REG_ISR); writew(IMR_ENABLE_ALL, i2c_dev->base + REG_IMR); writew(CR_ENABLE, i2c_dev->base + REG_CR); readw(i2c_dev->base + REG_CSR); /* read clear */ writew(ISR_WRITE_ALL, i2c_dev->base + REG_ISR); if (i2c_dev->mode == I2C_MODE_STANDARD) writew(SCL_TIMEOUT(128) | TR_STD, i2c_dev->base + REG_TR); else writew(SCL_TIMEOUT(128) | TR_HS, i2c_dev->base + REG_TR); return 0; } static int wmt_i2c_probe(struct platform_device *pdev) { struct device_node *np = pdev->dev.of_node; struct wmt_i2c_dev *i2c_dev; struct i2c_adapter *adap; struct resource *res; int err; u32 clk_rate; i2c_dev = devm_kzalloc(&pdev->dev, sizeof(*i2c_dev), GFP_KERNEL); if (!i2c_dev) return -ENOMEM; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); i2c_dev->base = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(i2c_dev->base)) return PTR_ERR(i2c_dev->base); i2c_dev->irq = irq_of_parse_and_map(np, 0); if (!i2c_dev->irq) { dev_err(&pdev->dev, "irq missing or invalid\n"); return -EINVAL; } i2c_dev->clk = of_clk_get(np, 0); if (IS_ERR(i2c_dev->clk)) { dev_err(&pdev->dev, "unable to request clock\n"); return PTR_ERR(i2c_dev->clk); } i2c_dev->mode = I2C_MODE_STANDARD; err = of_property_read_u32(np, "clock-frequency", &clk_rate); if (!err && (clk_rate == I2C_MAX_FAST_MODE_FREQ)) i2c_dev->mode = I2C_MODE_FAST; i2c_dev->dev = &pdev->dev; err = devm_request_irq(&pdev->dev, i2c_dev->irq, wmt_i2c_isr, 0, "i2c", i2c_dev); if (err) { dev_err(&pdev->dev, "failed to request irq %i\n", i2c_dev->irq); return err; } adap = &i2c_dev->adapter; i2c_set_adapdata(adap, i2c_dev); strscpy(adap->name, "WMT I2C adapter", sizeof(adap->name)); adap->owner = THIS_MODULE; adap->algo = &wmt_i2c_algo; adap->dev.parent = &pdev->dev; adap->dev.of_node = pdev->dev.of_node; init_completion(&i2c_dev->complete); err = wmt_i2c_reset_hardware(i2c_dev); if (err) { dev_err(&pdev->dev, "error initializing hardware\n"); return err; } err = i2c_add_adapter(adap); if (err) return err; platform_set_drvdata(pdev, i2c_dev); return 0; } static int wmt_i2c_remove(struct platform_device *pdev) { struct wmt_i2c_dev *i2c_dev = platform_get_drvdata(pdev); /* Disable interrupts, clock and delete adapter */ writew(0, i2c_dev->base + REG_IMR); clk_disable_unprepare(i2c_dev->clk); i2c_del_adapter(&i2c_dev->adapter); return 0; } static const struct of_device_id wmt_i2c_dt_ids[] = { { .compatible = "wm,wm8505-i2c" }, { /* Sentinel */ }, }; static struct platform_driver wmt_i2c_driver = { .probe = wmt_i2c_probe, .remove = wmt_i2c_remove, .driver = { .name = "wmt-i2c", .of_match_table = wmt_i2c_dt_ids, }, }; module_platform_driver(wmt_i2c_driver); MODULE_DESCRIPTION("Wondermedia I2C master-mode bus adapter"); MODULE_AUTHOR("Tony Prisk <linux@prisktech.co.nz>"); MODULE_LICENSE("GPL"); MODULE_DEVICE_TABLE(of, wmt_i2c_dt_ids);
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