From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-lb0-f176.google.com ([209.85.217.176]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1X7Whs-0001Ul-IY for barebox@lists.infradead.org; Wed, 16 Jul 2014 21:25:46 +0000 Received: by mail-lb0-f176.google.com with SMTP id u10so817513lbd.7 for ; Wed, 16 Jul 2014 14:25:19 -0700 (PDT) From: Antony Pavlov Date: Thu, 17 Jul 2014 01:25:09 +0400 Message-Id: <1405545909-9855-2-git-send-email-antonynpavlov@gmail.com> In-Reply-To: <1405545909-9855-1-git-send-email-antonynpavlov@gmail.com> References: <1405545909-9855-1-git-send-email-antonynpavlov@gmail.com> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "barebox" Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: [PATCH v2] i2c: add Marvell 64xxx driver To: barebox@lists.infradead.org This driver is also used for Allwinner SoCs I2C controllers. Ported from linux-3.15. The most notable barebox driver version changes: * drop message offloading support; * add reg-io-width parameter to use driver with byte-oriented controller versions. Signed-off-by: Antony Pavlov --- drivers/i2c/busses/Kconfig | 8 + drivers/i2c/busses/Makefile | 1 + drivers/i2c/busses/i2c-mv64xxx.c | 687 +++++++++++++++++++++++++++++++++++++++ 3 files changed, 696 insertions(+) diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index 370abb0..851556f 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -16,6 +16,14 @@ config I2C_IMX bool "MPC85xx/i.MX I2C Master driver" depends on (ARCH_IMX && !ARCH_IMX1) || ARCH_MPC85XX +config I2C_MV64XXX + bool "Marvell mv64xxx I2C Controller" + depends on HAVE_CLK && OFDEVICE + help + If you say yes to this option, support will be included for the + built-in I2C interface on the Marvell 64xxx line of host bridges. + This driver is also used for Allwinner SoCs I2C controllers. + config I2C_OMAP bool "OMAP I2C Master driver" depends on ARCH_OMAP diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile index 9823d1b..4e4f6ba 100644 --- a/drivers/i2c/busses/Makefile +++ b/drivers/i2c/busses/Makefile @@ -1,5 +1,6 @@ obj-$(CONFIG_I2C_GPIO) += i2c-gpio.o obj-$(CONFIG_I2C_IMX) += i2c-imx.o +obj-$(CONFIG_I2C_MV64XXX) += i2c-mv64xxx.o obj-$(CONFIG_I2C_OMAP) += i2c-omap.o obj-$(CONFIG_I2C_TEGRA) += i2c-tegra.o obj-$(CONFIG_I2C_VERSATILE) += i2c-versatile.o diff --git a/drivers/i2c/busses/i2c-mv64xxx.c b/drivers/i2c/busses/i2c-mv64xxx.c new file mode 100644 index 0000000..324796a --- /dev/null +++ b/drivers/i2c/busses/i2c-mv64xxx.c @@ -0,0 +1,687 @@ +/* + * Driver for the i2c controller on the Marvell line of host bridges + * (e.g, gt642[46]0, mv643[46]0, mv644[46]0, and Orion SoC family). + * + * This code was ported from linux-3.15 kernel by Antony Pavlov. + * + * Author: Mark A. Greer + * + * 2005 (c) MontaVista, Software, Inc. 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. + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include + +#define MV64XXX_I2C_ADDR_ADDR(val) ((val & 0x7f) << 1) +#define MV64XXX_I2C_BAUD_DIV_N(val) (val & 0x7) +#define MV64XXX_I2C_BAUD_DIV_M(val) ((val & 0xf) << 3) + +#define MV64XXX_I2C_REG_CONTROL_ACK 0x00000004 +#define MV64XXX_I2C_REG_CONTROL_IFLG 0x00000008 +#define MV64XXX_I2C_REG_CONTROL_STOP 0x00000010 +#define MV64XXX_I2C_REG_CONTROL_START 0x00000020 +#define MV64XXX_I2C_REG_CONTROL_TWSIEN 0x00000040 +#define MV64XXX_I2C_REG_CONTROL_INTEN 0x00000080 + +/* Ctlr status values */ +#define MV64XXX_I2C_STATUS_BUS_ERR 0x00 +#define MV64XXX_I2C_STATUS_MAST_START 0x08 +#define MV64XXX_I2C_STATUS_MAST_REPEAT_START 0x10 +#define MV64XXX_I2C_STATUS_MAST_WR_ADDR_ACK 0x18 +#define MV64XXX_I2C_STATUS_MAST_WR_ADDR_NO_ACK 0x20 +#define MV64XXX_I2C_STATUS_MAST_WR_ACK 0x28 +#define MV64XXX_I2C_STATUS_MAST_WR_NO_ACK 0x30 +#define MV64XXX_I2C_STATUS_MAST_LOST_ARB 0x38 +#define MV64XXX_I2C_STATUS_MAST_RD_ADDR_ACK 0x40 +#define MV64XXX_I2C_STATUS_MAST_RD_ADDR_NO_ACK 0x48 +#define MV64XXX_I2C_STATUS_MAST_RD_DATA_ACK 0x50 +#define MV64XXX_I2C_STATUS_MAST_RD_DATA_NO_ACK 0x58 +#define MV64XXX_I2C_STATUS_MAST_WR_ADDR_2_ACK 0xd0 +#define MV64XXX_I2C_STATUS_MAST_WR_ADDR_2_NO_ACK 0xd8 +#define MV64XXX_I2C_STATUS_MAST_RD_ADDR_2_ACK 0xe0 +#define MV64XXX_I2C_STATUS_MAST_RD_ADDR_2_NO_ACK 0xe8 +#define MV64XXX_I2C_STATUS_NO_STATUS 0xf8 + +/* Driver states */ +enum { + MV64XXX_I2C_STATE_INVALID, + MV64XXX_I2C_STATE_IDLE, + MV64XXX_I2C_STATE_WAITING_FOR_START_COND, + MV64XXX_I2C_STATE_WAITING_FOR_RESTART, + MV64XXX_I2C_STATE_WAITING_FOR_ADDR_1_ACK, + MV64XXX_I2C_STATE_WAITING_FOR_ADDR_2_ACK, + MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_ACK, + MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_DATA, +}; + +/* Driver actions */ +enum { + MV64XXX_I2C_ACTION_INVALID, + MV64XXX_I2C_ACTION_CONTINUE, + MV64XXX_I2C_ACTION_SEND_RESTART, + MV64XXX_I2C_ACTION_OFFLOAD_RESTART, + MV64XXX_I2C_ACTION_SEND_ADDR_1, + MV64XXX_I2C_ACTION_SEND_ADDR_2, + MV64XXX_I2C_ACTION_SEND_DATA, + MV64XXX_I2C_ACTION_RCV_DATA, + MV64XXX_I2C_ACTION_RCV_DATA_STOP, + MV64XXX_I2C_ACTION_SEND_STOP, + MV64XXX_I2C_ACTION_OFFLOAD_SEND_STOP, +}; + +struct mv64xxx_i2c_regs { + u8 addr; + u8 ext_addr; + u8 data; + u8 control; + u8 status; + u8 clock; + u8 soft_reset; +}; + +struct mv64xxx_i2c_data { + struct i2c_msg *msgs; + int num_msgs; + u32 state; + u32 action; + u32 aborting; + u32 cntl_bits; + void __iomem *reg_base; + struct mv64xxx_i2c_regs reg_offsets; + u32 addr1; + u32 addr2; + u32 bytes_left; + u32 byte_posn; + u32 send_stop; + u32 block; + int rc; + u32 freq_m; + u32 freq_n; + struct clk *clk; + struct i2c_msg *msg; + struct i2c_adapter adapter; +/* 5us delay in order to avoid repeated start timing violation */ + bool errata_delay; + struct reset_control *rstc; + bool irq_clear_inverted; + int reg_io_width; +}; + +static struct mv64xxx_i2c_regs mv64xxx_i2c_regs_mv64xxx = { + .addr = 0x00, + .ext_addr = 0x10, + .data = 0x04, + .control = 0x08, + .status = 0x0c, + .clock = 0x0c, + .soft_reset = 0x1c, +}; + +static struct mv64xxx_i2c_regs mv64xxx_i2c_regs_sun4i = { + .addr = 0x00, + .ext_addr = 0x04, + .data = 0x08, + .control = 0x0c, + .status = 0x10, + .clock = 0x14, + .soft_reset = 0x18, +}; + +static inline void mv64xxx_write(struct mv64xxx_i2c_data *drv_data, u32 v, int reg) +{ + void *addr = drv_data->reg_base + reg; + + switch (drv_data->reg_io_width) { + case IORESOURCE_MEM_8BIT: + writeb((u8)v, addr); + break; + case IORESOURCE_MEM_32BIT: + writel(v, addr); + break; + default: + dev_err(&drv_data->adapter.dev, + "%s: wrong reg_io_width!\n", __func__); + } +} + +static inline u32 mv64xxx_read(struct mv64xxx_i2c_data *drv_data, int reg) +{ + void *addr = drv_data->reg_base + reg; + u32 r; + + switch (drv_data->reg_io_width) { + case IORESOURCE_MEM_8BIT: + r = readb(addr); + break; + + case IORESOURCE_MEM_32BIT: + r = readl(addr); + break; + + default: + dev_err(&drv_data->adapter.dev, + "%s: wrong reg_io_width!\n", __func__); + r = 0xffffffff; + } + + return r; +} + +static void +mv64xxx_i2c_prepare_for_io(struct mv64xxx_i2c_data *drv_data, + struct i2c_msg *msg) +{ + u32 dir = 0; + + drv_data->cntl_bits = MV64XXX_I2C_REG_CONTROL_ACK | + MV64XXX_I2C_REG_CONTROL_INTEN | MV64XXX_I2C_REG_CONTROL_TWSIEN; + + if (msg->flags & I2C_M_RD) + dir = 1; + + if (msg->flags & I2C_M_TEN) { + drv_data->addr1 = 0xf0 | (((u32)msg->addr & 0x300) >> 7) | dir; + drv_data->addr2 = (u32)msg->addr & 0xff; + } else { + drv_data->addr1 = MV64XXX_I2C_ADDR_ADDR((u32)msg->addr) | dir; + drv_data->addr2 = 0; + } +} + +/* + ***************************************************************************** + * + * Finite State Machine & Interrupt Routines + * + ***************************************************************************** + */ + +/* Reset hardware and initialize FSM */ +static void +mv64xxx_i2c_hw_init(struct mv64xxx_i2c_data *drv_data) +{ + mv64xxx_write(drv_data, 0, drv_data->reg_offsets.soft_reset); + mv64xxx_write(drv_data, MV64XXX_I2C_BAUD_DIV_M(drv_data->freq_m) | MV64XXX_I2C_BAUD_DIV_N(drv_data->freq_n), + drv_data->reg_offsets.clock); + mv64xxx_write(drv_data, 0, drv_data->reg_offsets.addr); + mv64xxx_write(drv_data, 0, drv_data->reg_offsets.ext_addr); + mv64xxx_write(drv_data, MV64XXX_I2C_REG_CONTROL_TWSIEN | MV64XXX_I2C_REG_CONTROL_STOP, + drv_data->reg_offsets.control); + drv_data->state = MV64XXX_I2C_STATE_IDLE; +} + +static void +mv64xxx_i2c_fsm(struct mv64xxx_i2c_data *drv_data, u32 status) +{ + /* + * If state is idle, then this is likely the remnants of an old + * operation that driver has given up on or the user has killed. + * If so, issue the stop condition and go to idle. + */ + if (drv_data->state == MV64XXX_I2C_STATE_IDLE) { + drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP; + return; + } + + /* The status from the ctlr [mostly] tells us what to do next */ + switch (status) { + /* Start condition interrupt */ + case MV64XXX_I2C_STATUS_MAST_START: /* 0x08 */ + case MV64XXX_I2C_STATUS_MAST_REPEAT_START: /* 0x10 */ + drv_data->action = MV64XXX_I2C_ACTION_SEND_ADDR_1; + drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_ADDR_1_ACK; + break; + + /* Performing a write */ + case MV64XXX_I2C_STATUS_MAST_WR_ADDR_ACK: /* 0x18 */ + if (drv_data->msg->flags & I2C_M_TEN) { + drv_data->action = MV64XXX_I2C_ACTION_SEND_ADDR_2; + drv_data->state = + MV64XXX_I2C_STATE_WAITING_FOR_ADDR_2_ACK; + break; + } + /* FALLTHRU */ + case MV64XXX_I2C_STATUS_MAST_WR_ADDR_2_ACK: /* 0xd0 */ + case MV64XXX_I2C_STATUS_MAST_WR_ACK: /* 0x28 */ + if ((drv_data->bytes_left == 0) + || (drv_data->aborting + && (drv_data->byte_posn != 0))) { + if (drv_data->send_stop || drv_data->aborting) { + drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP; + drv_data->state = MV64XXX_I2C_STATE_IDLE; + } else { + drv_data->action = + MV64XXX_I2C_ACTION_SEND_RESTART; + drv_data->state = + MV64XXX_I2C_STATE_WAITING_FOR_RESTART; + } + } else { + drv_data->action = MV64XXX_I2C_ACTION_SEND_DATA; + drv_data->state = + MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_ACK; + drv_data->bytes_left--; + } + break; + + /* Performing a read */ + case MV64XXX_I2C_STATUS_MAST_RD_ADDR_ACK: /* 40 */ + if (drv_data->msg->flags & I2C_M_TEN) { + drv_data->action = MV64XXX_I2C_ACTION_SEND_ADDR_2; + drv_data->state = + MV64XXX_I2C_STATE_WAITING_FOR_ADDR_2_ACK; + break; + } + /* FALLTHRU */ + case MV64XXX_I2C_STATUS_MAST_RD_ADDR_2_ACK: /* 0xe0 */ + if (drv_data->bytes_left == 0) { + drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP; + drv_data->state = MV64XXX_I2C_STATE_IDLE; + break; + } + /* FALLTHRU */ + case MV64XXX_I2C_STATUS_MAST_RD_DATA_ACK: /* 0x50 */ + if (status != MV64XXX_I2C_STATUS_MAST_RD_DATA_ACK) + drv_data->action = MV64XXX_I2C_ACTION_CONTINUE; + else { + drv_data->action = MV64XXX_I2C_ACTION_RCV_DATA; + drv_data->bytes_left--; + } + drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_DATA; + + if ((drv_data->bytes_left == 1) || drv_data->aborting) + drv_data->cntl_bits &= ~MV64XXX_I2C_REG_CONTROL_ACK; + break; + + case MV64XXX_I2C_STATUS_MAST_RD_DATA_NO_ACK: /* 0x58 */ + drv_data->action = MV64XXX_I2C_ACTION_RCV_DATA_STOP; + drv_data->state = MV64XXX_I2C_STATE_IDLE; + break; + + case MV64XXX_I2C_STATUS_MAST_WR_ADDR_NO_ACK: /* 0x20 */ + case MV64XXX_I2C_STATUS_MAST_WR_NO_ACK: /* 30 */ + case MV64XXX_I2C_STATUS_MAST_RD_ADDR_NO_ACK: /* 48 */ + /* Doesn't seem to be a device at other end */ + drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP; + drv_data->state = MV64XXX_I2C_STATE_IDLE; + drv_data->rc = -ENXIO; + break; + + default: + dev_err(&drv_data->adapter.dev, + "mv64xxx_i2c_fsm: Ctlr Error -- state: 0x%x, " + "status: 0x%x, addr: 0x%x, flags: 0x%x\n", + drv_data->state, status, drv_data->msg->addr, + drv_data->msg->flags); + drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP; + mv64xxx_i2c_hw_init(drv_data); + drv_data->rc = -EIO; + } +} + +static void mv64xxx_i2c_send_start(struct mv64xxx_i2c_data *drv_data) +{ + drv_data->msg = drv_data->msgs; + drv_data->byte_posn = 0; + drv_data->bytes_left = drv_data->msg->len; + drv_data->aborting = 0; + drv_data->rc = 0; + + mv64xxx_i2c_prepare_for_io(drv_data, drv_data->msgs); + mv64xxx_write(drv_data, drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_START, + drv_data->reg_offsets.control); +} + +static void +mv64xxx_i2c_do_action(struct mv64xxx_i2c_data *drv_data) +{ + switch (drv_data->action) { + case MV64XXX_I2C_ACTION_SEND_RESTART: + /* We should only get here if we have further messages */ + BUG_ON(drv_data->num_msgs == 0); + + drv_data->msgs++; + drv_data->num_msgs--; + mv64xxx_i2c_send_start(drv_data); + + if (drv_data->errata_delay) + udelay(5); + + /* + * We're never at the start of the message here, and by this + * time it's already too late to do any protocol mangling. + * Thankfully, do not advertise support for that feature. + */ + drv_data->send_stop = drv_data->num_msgs == 1; + break; + + case MV64XXX_I2C_ACTION_CONTINUE: + mv64xxx_write(drv_data, drv_data->cntl_bits, + drv_data->reg_offsets.control); + break; + + case MV64XXX_I2C_ACTION_SEND_ADDR_1: + mv64xxx_write(drv_data, drv_data->addr1, + drv_data->reg_offsets.data); + mv64xxx_write(drv_data, drv_data->cntl_bits, + drv_data->reg_offsets.control); + break; + + case MV64XXX_I2C_ACTION_SEND_ADDR_2: + mv64xxx_write(drv_data, drv_data->addr2, + drv_data->reg_offsets.data); + mv64xxx_write(drv_data, drv_data->cntl_bits, + drv_data->reg_offsets.control); + break; + + case MV64XXX_I2C_ACTION_SEND_DATA: + mv64xxx_write(drv_data, drv_data->msg->buf[drv_data->byte_posn++], + drv_data->reg_offsets.data); + mv64xxx_write(drv_data, drv_data->cntl_bits, + drv_data->reg_offsets.control); + break; + + case MV64XXX_I2C_ACTION_RCV_DATA: + drv_data->msg->buf[drv_data->byte_posn++] = + mv64xxx_read(drv_data, drv_data->reg_offsets.data); + mv64xxx_write(drv_data, drv_data->cntl_bits, + drv_data->reg_offsets.control); + break; + + case MV64XXX_I2C_ACTION_RCV_DATA_STOP: + drv_data->msg->buf[drv_data->byte_posn++] = + mv64xxx_read(drv_data, drv_data->reg_offsets.data); + drv_data->cntl_bits &= ~MV64XXX_I2C_REG_CONTROL_INTEN; + mv64xxx_write(drv_data, drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_STOP, + drv_data->reg_offsets.control); + drv_data->block = 0; + if (drv_data->errata_delay) + udelay(5); + + break; + + case MV64XXX_I2C_ACTION_INVALID: + default: + dev_err(&drv_data->adapter.dev, + "mv64xxx_i2c_do_action: Invalid action: %d\n", + drv_data->action); + drv_data->rc = -EIO; + + /* FALLTHRU */ + case MV64XXX_I2C_ACTION_SEND_STOP: + drv_data->cntl_bits &= ~MV64XXX_I2C_REG_CONTROL_INTEN; + mv64xxx_write(drv_data, drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_STOP, + drv_data->reg_offsets.control); + drv_data->block = 0; + break; + } +} + +static void mv64xxx_i2c_intr(struct mv64xxx_i2c_data *drv_data) +{ + u32 status; + uint64_t start; + + start = get_time_ns(); + + while (mv64xxx_read(drv_data, drv_data->reg_offsets.control) & + MV64XXX_I2C_REG_CONTROL_IFLG) { + status = mv64xxx_read(drv_data, drv_data->reg_offsets.status); + mv64xxx_i2c_fsm(drv_data, status); + mv64xxx_i2c_do_action(drv_data); + + if (drv_data->irq_clear_inverted) + mv64xxx_write(drv_data, drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_IFLG, + drv_data->reg_offsets.control); + + if (is_timeout_non_interruptible(start, 3 * SECOND)) { + drv_data->rc = -EIO; + break; + } + } +} + +/* + ***************************************************************************** + * + * I2C Msg Execution Routines + * + ***************************************************************************** + */ +static void +mv64xxx_i2c_wait_for_completion(struct mv64xxx_i2c_data *drv_data) +{ + do { + mv64xxx_i2c_intr(drv_data); + if (drv_data->rc) { + drv_data->state = MV64XXX_I2C_STATE_IDLE; + dev_err(&drv_data->adapter.dev, "I2C bus error\n"); + mv64xxx_i2c_hw_init(drv_data); + drv_data->block = 0; + } + } while (drv_data->block != 0); +} + +static int +mv64xxx_i2c_execute_msg(struct mv64xxx_i2c_data *drv_data, struct i2c_msg *msg, + int is_last) +{ + drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_START_COND; + + drv_data->send_stop = is_last; + drv_data->block = 1; + mv64xxx_i2c_send_start(drv_data); + mv64xxx_i2c_wait_for_completion(drv_data); + + return drv_data->rc; +} + +/* + ***************************************************************************** + * + * I2C Core Support Routines (Interface to higher level I2C code) + * + ***************************************************************************** + */ +static int +mv64xxx_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) +{ + struct mv64xxx_i2c_data *drv_data = container_of(adap, struct mv64xxx_i2c_data, adapter); + int rc, ret = num; + + BUG_ON(drv_data->msgs != NULL); + drv_data->msgs = msgs; + drv_data->num_msgs = num; + + rc = mv64xxx_i2c_execute_msg(drv_data, &msgs[0], num == 1); + if (rc < 0) + ret = rc; + + drv_data->num_msgs = 0; + drv_data->msgs = NULL; + + return ret; +} + +/* + ***************************************************************************** + * + * Driver Interface & Early Init Routines + * + ***************************************************************************** + */ +static struct of_device_id mv64xxx_i2c_of_match_table[] = { + { .compatible = "allwinner,sun4i-i2c", .data = (unsigned long)&mv64xxx_i2c_regs_sun4i}, + { .compatible = "allwinner,sun6i-a31-i2c", .data = (unsigned long)&mv64xxx_i2c_regs_sun4i}, + { .compatible = "marvell,mv64xxx-i2c", .data = (unsigned long)&mv64xxx_i2c_regs_mv64xxx}, + { .compatible = "marvell,mv78230-i2c", .data = (unsigned long)&mv64xxx_i2c_regs_mv64xxx}, + { .compatible = "marvell,mv78230-a0-i2c", .data = (unsigned long)&mv64xxx_i2c_regs_mv64xxx}, + {} +}; + +static int +mv64xxx_calc_freq(const int tclk, const int n, const int m) +{ + return tclk / (10 * (m + 1) * (2 << n)); +} + +static bool +mv64xxx_find_baud_factors(const u32 req_freq, const u32 tclk, u32 *best_n, + u32 *best_m) +{ + int freq, delta, best_delta = INT_MAX; + int m, n; + + for (n = 0; n <= 7; n++) + for (m = 0; m <= 15; m++) { + freq = mv64xxx_calc_freq(tclk, n, m); + delta = req_freq - freq; + if (delta >= 0 && delta < best_delta) { + *best_m = m; + *best_n = n; + best_delta = delta; + } + if (best_delta == 0) + return true; + } + if (best_delta == INT_MAX) + return false; + return true; +} + +static int +mv64xxx_of_config(struct mv64xxx_i2c_data *drv_data, + struct device_d *pd) +{ + struct device_node *np = pd->device_node; + u32 bus_freq, tclk; + int rc = 0; + u32 prop; + struct mv64xxx_i2c_regs *mv64xxx_regs; + int freq; + + if (IS_ERR(drv_data->clk)) { + rc = -ENODEV; + goto out; + } + tclk = clk_get_rate(drv_data->clk); + + rc = of_property_read_u32(np, "clock-frequency", &bus_freq); + if (rc) + bus_freq = 100000; /* 100kHz by default */ + + if (!mv64xxx_find_baud_factors(bus_freq, tclk, + &drv_data->freq_n, &drv_data->freq_m)) { + rc = -EINVAL; + goto out; + } + + freq = mv64xxx_calc_freq(tclk, drv_data->freq_n, drv_data->freq_m); + dev_dbg(pd, "tclk=%d freq_n=%d freq_m=%d freq=%d\n", + tclk, drv_data->freq_n, drv_data->freq_m, freq); + + drv_data->reg_io_width = IORESOURCE_MEM_32BIT; + + if (of_property_read_u32(np, "reg-io-width", &prop) == 0) { + switch (prop) { + case 1: + drv_data->reg_io_width = IORESOURCE_MEM_8BIT; + break; + case 4: + drv_data->reg_io_width = IORESOURCE_MEM_32BIT; + break; + default: + dev_err(pd, "unsupported reg-io-width (%d)\n", prop); + rc = -EINVAL; + goto out; + } + } + + dev_get_drvdata(pd, (unsigned long *)&mv64xxx_regs); + memcpy(&drv_data->reg_offsets, mv64xxx_regs, + sizeof(drv_data->reg_offsets)); + + /* + * For controllers embedded in new SoCs activate the + * Transaction Generator support and the errata fix. + */ + if (of_device_is_compatible(np, "marvell,mv78230-i2c")) { + drv_data->errata_delay = true; + } + + if (of_device_is_compatible(np, "marvell,mv78230-a0-i2c")) { + drv_data->errata_delay = true; + } + + if (of_device_is_compatible(np, "allwinner,sun6i-a31-i2c")) + drv_data->irq_clear_inverted = true; + +out: + return rc; +} + +static int +mv64xxx_i2c_probe(struct device_d *pd) +{ + struct mv64xxx_i2c_data *drv_data; + int rc; + + if (!pd->device_node) + return -ENODEV; + + drv_data = xzalloc(sizeof(*drv_data)); + + drv_data->reg_base = dev_request_mem_region(pd, 0); + if (IS_ERR(drv_data->reg_base)) + return PTR_ERR(drv_data->reg_base); + + drv_data->clk = clk_get(pd, NULL); + if (IS_ERR(drv_data->clk)) + return PTR_ERR(drv_data->clk); + + clk_enable(drv_data->clk); + + rc = mv64xxx_of_config(drv_data, pd); + if (rc) + goto exit_clk; + + drv_data->adapter.master_xfer = mv64xxx_i2c_xfer; + drv_data->adapter.dev.parent = pd; + drv_data->adapter.nr = pd->id; + drv_data->adapter.dev.device_node = pd->device_node; + + mv64xxx_i2c_hw_init(drv_data); + + rc = i2c_add_numbered_adapter(&drv_data->adapter); + if (rc) { + dev_err(pd, "Failed to add I2C adapter\n"); + goto exit_clk; + } + + return 0; + +exit_clk: + clk_disable(drv_data->clk); + + return rc; +} + +static struct driver_d mv64xxx_i2c_driver = { + .probe = mv64xxx_i2c_probe, + .name = "mv64xxx_i2c", + .of_compatible = DRV_OF_COMPAT(mv64xxx_i2c_of_match_table), +}; +device_platform_driver(mv64xxx_i2c_driver); -- 2.0.1 _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox