diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-wmt.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-wmt.c | 421 |
1 files changed, 0 insertions, 421 deletions
diff --git a/drivers/i2c/busses/i2c-wmt.c b/drivers/i2c/busses/i2c-wmt.c deleted file mode 100644 index 198afee523..0000000000 --- a/drivers/i2c/busses/i2c-wmt.c +++ /dev/null @@ -1,421 +0,0 @@ -// 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 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; - u16 tcr; - 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; - unsigned long wait_result; - - wait_result = wait_for_completion_timeout(&i2c_dev->complete, - msecs_to_jiffies(500)); - if (!wait_result) - return -ETIMEDOUT; - - 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 wmt_i2c_dev *i2c_dev, struct i2c_msg *pmsg, - int last) -{ - u16 val, tcr_val = i2c_dev->tcr; - int ret; - int xfer_len = 0; - - 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; - val |= CR_CPU_RDY; - writew(val, i2c_dev->base + REG_CR); - } - - reinit_completion(&i2c_dev->complete); - - 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) { - 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 wmt_i2c_dev *i2c_dev, struct i2c_msg *pmsg) -{ - u16 val, tcr_val = i2c_dev->tcr; - int ret; - u32 xfer_len = 0; - - val = readw(i2c_dev->base + REG_CR); - val &= ~(CR_TX_END | CR_TX_NEXT_NO_ACK); - - if (!(pmsg->flags & I2C_M_NOSTART)) - val |= CR_CPU_RDY; - - if (pmsg->len == 1) - val |= CR_TX_NEXT_NO_ACK; - - writew(val, i2c_dev->base + REG_CR); - - reinit_completion(&i2c_dev->complete); - - 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) { - ret = wmt_check_status(i2c_dev); - if (ret) - return ret; - - pmsg->buf[xfer_len] = readw(i2c_dev->base + REG_CDR) >> 8; - xfer_len++; - - val = readw(i2c_dev->base + REG_CR) | CR_CPU_RDY; - if (xfer_len == pmsg->len - 1) - val |= CR_TX_NEXT_NO_ACK; - 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; - int ret = 0; - struct wmt_i2c_dev *i2c_dev = i2c_get_adapdata(adap); - - for (i = 0; ret >= 0 && i < num; i++) { - pmsg = &msgs[i]; - if (!(pmsg->flags & I2C_M_NOSTART)) { - ret = wmt_i2c_wait_bus_not_busy(i2c_dev); - if (ret < 0) - return ret; - } - - if (pmsg->flags & I2C_M_RD) - ret = wmt_i2c_read(i2c_dev, pmsg); - else - ret = wmt_i2c_write(i2c_dev, pmsg, (i + 1) == num); - } - - 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->tcr == TCR_FAST_MODE) - writew(SCL_TIMEOUT(128) | TR_HS, i2c_dev->base + REG_TR); - else - writew(SCL_TIMEOUT(128) | TR_STD, 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; - int err; - u32 clk_rate; - - i2c_dev = devm_kzalloc(&pdev->dev, sizeof(*i2c_dev), GFP_KERNEL); - if (!i2c_dev) - return -ENOMEM; - - i2c_dev->base = devm_platform_get_and_ioremap_resource(pdev, 0, NULL); - 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); - } - - err = of_property_read_u32(np, "clock-frequency", &clk_rate); - if (!err && (clk_rate == I2C_MAX_FAST_MODE_FREQ)) - i2c_dev->tcr = TCR_FAST_MODE; - - 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) - goto err_disable_clk; - - platform_set_drvdata(pdev, i2c_dev); - - return 0; - -err_disable_clk: - clk_disable_unprepare(i2c_dev->clk); - return err; -} - -static void 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); -} - -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_new = 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); |