From d5c54ff3d1db0a4348fa04d8e78f3bf6063e3afc Mon Sep 17 00:00:00 2001 From: John Crispin Date: Mon, 7 Dec 2015 17:21:27 +0100 Subject: [PATCH 45/53] i2c: add mt7621 driver Signed-off-by: John Crispin --- drivers/i2c/busses/Kconfig | 4 + drivers/i2c/busses/Makefile | 1 + drivers/i2c/busses/i2c-mt7621.c | 303 +++++++++++++++++++++++++++++++++++++++ 3 files changed, 308 insertions(+) create mode 100644 drivers/i2c/busses/i2c-mt7621.c --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -811,6 +811,11 @@ config I2C_RALINK depends on RALINK && !SOC_MT7621 select OF_I2C +config I2C_MT7621 + tristate "MT7621/MT7628 I2C Controller" + depends on RALINK && (SOC_MT7620 || SOC_MT7621) + select OF_I2C + config HAVE_S3C2410_I2C bool help --- a/drivers/i2c/busses/Makefile +++ b/drivers/i2c/busses/Makefile @@ -76,6 +76,7 @@ obj-$(CONFIG_I2C_PUV3) += i2c-puv3.o obj-$(CONFIG_I2C_PXA) += i2c-pxa.o obj-$(CONFIG_I2C_PXA_PCI) += i2c-pxa-pci.o obj-$(CONFIG_I2C_RALINK) += i2c-ralink.o +obj-$(CONFIG_I2C_MT7621) += i2c-mt7621.o obj-$(CONFIG_I2C_QUP) += i2c-qup.o obj-$(CONFIG_I2C_RIIC) += i2c-riic.o obj-$(CONFIG_I2C_RK3X) += i2c-rk3x.o --- /dev/null +++ b/drivers/i2c/busses/i2c-mt7621.c @@ -0,0 +1,433 @@ +/* + * drivers/i2c/busses/i2c-mt7621.c + * + * Copyright (C) 2013 Steven Liu + * Copyright (C) 2016 Michael Lee + * + * Improve driver for i2cdetect from i2c-tools to detect i2c devices on the bus. + * (C) 2014 Sittisak + * + * This software is licensed under the terms of the GNU General Public + * License version 2, as published by the Free Software Foundation, and + * may be copied, distributed, and modified under those terms. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define REG_SM0CFG0 0x08 +#define REG_SM0DOUT 0x10 +#define REG_SM0DIN 0x14 +#define REG_SM0ST 0x18 +#define REG_SM0AUTO 0x1C +#define REG_SM0CFG1 0x20 +#define REG_SM0CFG2 0x28 +#define REG_SM0CTL0 0x40 +#define REG_SM0CTL1 0x44 +#define REG_SM0D0 0x50 +#define REG_SM0D1 0x54 +#define REG_PINTEN 0x5C +#define REG_PINTST 0x60 +#define REG_PINTCL 0x64 + +/* REG_SM0CFG0 */ +#define I2C_DEVADDR_MASK 0x7f + +/* REG_SM0ST */ +#define I2C_DATARDY BIT(2) +#define I2C_SDOEMPTY BIT(1) +#define I2C_BUSY BIT(0) + +/* REG_SM0AUTO */ +#define READ_CMD BIT(0) + +/* REG_SM0CFG1 */ +#define BYTECNT_MAX 64 +#define SET_BYTECNT(x) (x - 1) + +/* REG_SM0CFG2 */ +#define AUTOMODE_EN BIT(0) + +/* REG_SM0CTL0 */ +#define ODRAIN_HIGH_SM0 BIT(31) +#define VSYNC_SHIFT 28 +#define VSYNC_MASK 0x3 +#define VSYNC_PULSE (0x1 << VSYNC_SHIFT) +#define VSYNC_RISING (0x2 << VSYNC_SHIFT) +#define CLK_DIV_SHIFT 16 +#define CLK_DIV_MASK 0xfff +#define DEG_CNT_SHIFT 8 +#define DEG_CNT_MASK 0xff +#define WAIT_HIGH BIT(6) +#define DEG_EN BIT(5) +#define CS_STATUA BIT(4) +#define SCL_STATUS BIT(3) +#define SDA_STATUS BIT(2) +#define SM0_EN BIT(1) +#define SCL_STRECH BIT(0) + +/* REG_SM0CTL1 */ +#define ACK_SHIFT 16 +#define ACK_MASK 0xff +#define PGLEN_SHIFT 8 +#define PGLEN_MASK 0x7 +#define SM0_MODE_SHIFT 4 +#define SM0_MODE_MASK 0x7 +#define SM0_MODE_START 0x1 +#define SM0_MODE_WRITE 0x2 +#define SM0_MODE_STOP 0x3 +#define SM0_MODE_READ_NACK 0x4 +#define SM0_MODE_READ_ACK 0x5 +#define SM0_TRI_BUSY BIT(0) + +/* timeout waiting for I2C devices to respond (clock streching) */ +#define TIMEOUT_MS 1000 +#define DELAY_INTERVAL_US 100 + +struct mtk_i2c { + void __iomem *base; + struct clk *clk; + struct device *dev; + struct i2c_adapter adap; + u32 cur_clk; + u32 clk_div; + u32 flags; +}; + +static void mtk_i2c_w32(struct mtk_i2c *i2c, u32 val, unsigned reg) +{ + iowrite32(val, i2c->base + reg); +} + +static u32 mtk_i2c_r32(struct mtk_i2c *i2c, unsigned reg) +{ + return ioread32(i2c->base + reg); +} + +static int poll_down_timeout(void __iomem *addr, u32 mask) +{ + unsigned long timeout = jiffies + msecs_to_jiffies(TIMEOUT_MS); + + do { + if (!(readl_relaxed(addr) & mask)) + return 0; + + usleep_range(DELAY_INTERVAL_US, DELAY_INTERVAL_US + 50); + } while (time_before(jiffies, timeout)); + + return (readl_relaxed(addr) & mask) ? -EAGAIN : 0; +} + +static int mtk_i2c_wait_idle(struct mtk_i2c *i2c) +{ + int ret; + + ret = poll_down_timeout(i2c->base + REG_SM0ST, I2C_BUSY); + if (ret < 0) + dev_dbg(i2c->dev, "idle err(%d)\n", ret); + + return ret; +} + +static int poll_up_timeout(void __iomem *addr, u32 mask) +{ + unsigned long timeout = jiffies + msecs_to_jiffies(TIMEOUT_MS); + u32 status; + + do { + status = readl_relaxed(addr); + if (status & mask) + return 0; + usleep_range(DELAY_INTERVAL_US, DELAY_INTERVAL_US + 50); + } while (time_before(jiffies, timeout)); + + return -ETIMEDOUT; +} + +static int mtk_i2c_wait_rx_done(struct mtk_i2c *i2c) +{ + int ret; + + ret = poll_up_timeout(i2c->base + REG_SM0ST, I2C_DATARDY); + if (ret < 0) + dev_dbg(i2c->dev, "rx err(%d)\n", ret); + + return ret; +} + +static int mtk_i2c_wait_tx_done(struct mtk_i2c *i2c) +{ + int ret; + + ret = poll_up_timeout(i2c->base + REG_SM0ST, I2C_SDOEMPTY); + if (ret < 0) + dev_dbg(i2c->dev, "tx err(%d)\n", ret); + + return ret; +} + +static void mtk_i2c_reset(struct mtk_i2c *i2c) +{ + u32 reg; + device_reset(i2c->adap.dev.parent); + barrier(); + + /* ctrl0 */ + reg = ODRAIN_HIGH_SM0 | VSYNC_PULSE | (i2c->clk_div << CLK_DIV_SHIFT) | + WAIT_HIGH | SM0_EN; + mtk_i2c_w32(i2c, reg, REG_SM0CTL0); + + /* auto mode */ + mtk_i2c_w32(i2c, AUTOMODE_EN, REG_SM0CFG2); +} + +static void mtk_i2c_dump_reg(struct mtk_i2c *i2c) +{ + dev_dbg(i2c->dev, "cfg0 %08x, dout %08x, din %08x, " \ + "status %08x, auto %08x, cfg1 %08x, " \ + "cfg2 %08x, ctl0 %08x, ctl1 %08x\n", + mtk_i2c_r32(i2c, REG_SM0CFG0), + mtk_i2c_r32(i2c, REG_SM0DOUT), + mtk_i2c_r32(i2c, REG_SM0DIN), + mtk_i2c_r32(i2c, REG_SM0ST), + mtk_i2c_r32(i2c, REG_SM0AUTO), + mtk_i2c_r32(i2c, REG_SM0CFG1), + mtk_i2c_r32(i2c, REG_SM0CFG2), + mtk_i2c_r32(i2c, REG_SM0CTL0), + mtk_i2c_r32(i2c, REG_SM0CTL1)); +} + +static int mtk_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, + int num) +{ + struct mtk_i2c *i2c; + struct i2c_msg *pmsg; + int i, j, ret; + u32 cmd; + + i2c = i2c_get_adapdata(adap); + + for (i = 0; i < num; i++) { + pmsg = &msgs[i]; + cmd = 0; + + dev_dbg(i2c->dev, "addr: 0x%x, len: %d, flags: 0x%x\n", + pmsg->addr, pmsg->len, pmsg->flags); + + /* wait hardware idle */ + if ((ret = mtk_i2c_wait_idle(i2c))) + goto err_timeout; + + if (pmsg->flags & I2C_M_TEN) { + dev_dbg(i2c->dev, "10 bits addr not supported\n"); + return -EINVAL; + } else { + /* 7 bits address */ + mtk_i2c_w32(i2c, pmsg->addr & I2C_DEVADDR_MASK, + REG_SM0CFG0); + } + + /* buffer length */ + if (pmsg->len == 0) { + dev_dbg(i2c->dev, "length is 0\n"); + return -EINVAL; + } else + mtk_i2c_w32(i2c, SET_BYTECNT(pmsg->len), + REG_SM0CFG1); + + j = 0; + if (pmsg->flags & I2C_M_RD) { + cmd |= READ_CMD; + /* start transfer */ + barrier(); + mtk_i2c_w32(i2c, cmd, REG_SM0AUTO); + do { + /* wait */ + if ((ret = mtk_i2c_wait_rx_done(i2c))) + goto err_timeout; + /* read data */ + if (pmsg->len) + pmsg->buf[j] = mtk_i2c_r32(i2c, + REG_SM0DIN); + j++; + } while (j < pmsg->len); + } else { + do { + /* write data */ + if (pmsg->len) + mtk_i2c_w32(i2c, pmsg->buf[j], + REG_SM0DOUT); + /* start transfer */ + if (j == 0) { + barrier(); + mtk_i2c_w32(i2c, cmd, REG_SM0AUTO); + } + /* wait */ + if ((ret = mtk_i2c_wait_tx_done(i2c))) + goto err_timeout; + j++; + } while (j < pmsg->len); + } + } + /* the return value is number of executed messages */ + ret = i; + + return ret; + +err_timeout: + mtk_i2c_dump_reg(i2c); + mtk_i2c_reset(i2c); + return ret; +} + +static u32 mtk_i2c_func(struct i2c_adapter *a) +{ + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; +} + +static const struct i2c_algorithm mtk_i2c_algo = { + .master_xfer = mtk_i2c_master_xfer, + .functionality = mtk_i2c_func, +}; + +static const struct of_device_id i2c_mtk_dt_ids[] = { + { .compatible = "mediatek,mt7621-i2c" }, + { /* sentinel */ } +}; + +MODULE_DEVICE_TABLE(of, i2c_mtk_dt_ids); + +static struct i2c_adapter_quirks mtk_i2c_quirks = { + .max_write_len = BYTECNT_MAX, + .max_read_len = BYTECNT_MAX, +}; + +static void mtk_i2c_init(struct mtk_i2c *i2c) +{ + i2c->clk_div = clk_get_rate(i2c->clk) / i2c->cur_clk; + if (i2c->clk_div > CLK_DIV_MASK) + i2c->clk_div = CLK_DIV_MASK; + + mtk_i2c_reset(i2c); +} + +static int mtk_i2c_probe(struct platform_device *pdev) +{ + struct resource *res; + struct mtk_i2c *i2c; + struct i2c_adapter *adap; + const struct of_device_id *match; + int ret; + + match = of_match_device(i2c_mtk_dt_ids, &pdev->dev); + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) { + dev_err(&pdev->dev, "no memory resource found\n"); + return -ENODEV; + } + + i2c = devm_kzalloc(&pdev->dev, sizeof(struct mtk_i2c), GFP_KERNEL); + if (!i2c) { + dev_err(&pdev->dev, "failed to allocate i2c_adapter\n"); + return -ENOMEM; + } + + i2c->base = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(i2c->base)) + return PTR_ERR(i2c->base); + + i2c->clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(i2c->clk)) { + dev_err(&pdev->dev, "no clock defined\n"); + return -ENODEV; + } + clk_prepare_enable(i2c->clk); + i2c->dev = &pdev->dev; + + if (of_property_read_u32(pdev->dev.of_node, + "clock-frequency", &i2c->cur_clk)) + i2c->cur_clk = 100000; + + adap = &i2c->adap; + adap->owner = THIS_MODULE; + adap->class = I2C_CLASS_HWMON | I2C_CLASS_SPD; + adap->algo = &mtk_i2c_algo; + adap->retries = 3; + adap->dev.parent = &pdev->dev; + i2c_set_adapdata(adap, i2c); + adap->dev.of_node = pdev->dev.of_node; + strlcpy(adap->name, dev_name(&pdev->dev), sizeof(adap->name)); + adap->quirks = &mtk_i2c_quirks; + + platform_set_drvdata(pdev, i2c); + + mtk_i2c_init(i2c); + + ret = i2c_add_adapter(adap); + if (ret < 0) { + dev_err(&pdev->dev, "failed to add adapter\n"); + clk_disable_unprepare(i2c->clk); + return ret; + } + + dev_info(&pdev->dev, "clock %uKHz, re-start not support\n", + i2c->cur_clk/1000); + + return ret; +} + +static int mtk_i2c_remove(struct platform_device *pdev) +{ + struct mtk_i2c *i2c = platform_get_drvdata(pdev); + + i2c_del_adapter(&i2c->adap); + clk_disable_unprepare(i2c->clk); + + return 0; +} + +static struct platform_driver mtk_i2c_driver = { + .probe = mtk_i2c_probe, + .remove = mtk_i2c_remove, + .driver = { + .owner = THIS_MODULE, + .name = "i2c-mt7621", + .of_match_table = i2c_mtk_dt_ids, + }, +}; + +static int __init i2c_mtk_init (void) +{ + return platform_driver_register(&mtk_i2c_driver); +} +subsys_initcall(i2c_mtk_init); + +static void __exit i2c_mtk_exit (void) +{ + platform_driver_unregister(&mtk_i2c_driver); +} +module_exit(i2c_mtk_exit); + +MODULE_AUTHOR("Steven Liu "); +MODULE_DESCRIPTION("MT7621 I2c host driver"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:MT7621-I2C");