From 64ef094bc5b6dee4d9d44f4efd5f594a5979c08d Mon Sep 17 00:00:00 2001 From: Mario Six Date: Mon, 15 Jan 2018 11:08:10 +0100 Subject: [PATCH] i2c: ihs_i2c: Prepare DM conversion Prepare the function interface of the ihs_i2c driver for DM conversion in a future patch. While we're at it, fix some style violations, and make the code more readable. Signed-off-by: Mario Six --- drivers/i2c/ihs_i2c.c | 69 +++++++++++++++++++++++++------------------ 1 file changed, 40 insertions(+), 29 deletions(-) diff --git a/drivers/i2c/ihs_i2c.c b/drivers/i2c/ihs_i2c.c index 29612e69fe..6fd016339c 100644 --- a/drivers/i2c/ihs_i2c.c +++ b/drivers/i2c/ihs_i2c.c @@ -11,6 +11,7 @@ #include #include #include +#include DECLARE_GLOBAL_DATA_PTR; @@ -41,30 +42,38 @@ DECLARE_GLOBAL_DATA_PTR; #endif enum { - I2CINT_ERROR_EV = 1 << 13, - I2CINT_TRANSMIT_EV = 1 << 14, - I2CINT_RECEIVE_EV = 1 << 15, + I2CINT_ERROR_EV = BIT(13), + I2CINT_TRANSMIT_EV = BIT(14), + I2CINT_RECEIVE_EV = BIT(15), }; enum { + I2CMB_READ = 0 << 10, I2CMB_WRITE = 1 << 10, + I2CMB_1BYTE = 0 << 11, I2CMB_2BYTE = 1 << 11, + I2CMB_DONT_HOLD_BUS = 0 << 13, I2CMB_HOLD_BUS = 1 << 13, I2CMB_NATIVE = 2 << 14, }; +enum { + I2COP_WRITE = 0, + I2COP_READ = 1, +}; + static int wait_for_int(bool read) { u16 val; - unsigned int ctr = 0; + uint ctr = 0; I2C_GET_REG(interrupt_status, &val); + /* Wait until error or receive/transmit interrupt was raised */ while (!(val & (I2CINT_ERROR_EV | (read ? I2CINT_RECEIVE_EV : I2CINT_TRANSMIT_EV)))) { udelay(10); - if (ctr++ > 5000) { + if (ctr++ > 5000) return 1; - } I2C_GET_REG(interrupt_status, &val); } @@ -76,10 +85,12 @@ static int ihs_i2c_transfer(uchar chip, uchar *buffer, int len, bool read, { u16 val; + /* Clear interrupt status */ I2C_SET_REG(interrupt_status, I2CINT_ERROR_EV | I2CINT_RECEIVE_EV | I2CINT_TRANSMIT_EV); I2C_GET_REG(interrupt_status, &val); + /* If we want to write and have data, write the bytes to the mailbox */ if (!read && len) { val = buffer[0]; @@ -98,6 +109,7 @@ static int ihs_i2c_transfer(uchar chip, uchar *buffer, int len, bool read, if (wait_for_int(read)) return 1; + /* If we want to read, get the bytes from the mailbox */ if (read) { I2C_GET_REG(read_mailbox_ext, &val); buffer[0] = val & 0xff; @@ -108,55 +120,44 @@ static int ihs_i2c_transfer(uchar chip, uchar *buffer, int len, bool read, return 0; } -static int ihs_i2c_address(uchar chip, uint addr, int alen, bool hold_bus) +static int ihs_i2c_address(uchar chip, u8 *addr, int alen, bool hold_bus) { - int shift = (alen-1) * 8; - while (alen) { int transfer = min(alen, 2); - uchar buf[2]; bool is_last = alen <= transfer; - buf[0] = addr >> shift; - if (alen > 1) - buf[1] = addr >> (shift - 8); - - if (ihs_i2c_transfer(chip, buf, transfer, false, + if (ihs_i2c_transfer(chip, addr, transfer, I2COP_WRITE, hold_bus ? false : is_last)) return 1; - shift -= 16; alen -= transfer; } return 0; } -static int ihs_i2c_access(struct i2c_adapter *adap, uchar chip, uint addr, - int alen, uchar *buffer, int len, bool read) +static int ihs_i2c_access(struct i2c_adapter *adap, uchar chip, u8 *addr, + int alen, uchar *buffer, int len, int read) { - if (len <= 0) - return 1; - - if (ihs_i2c_address(chip, addr, alen, len)) + /* Don't hold the bus if length of data to send/receive is zero */ + if (len <= 0 || ihs_i2c_address(chip, addr, alen, len)) return 1; while (len) { int transfer = min(len, 2); + bool is_last = len <= transfer; if (ihs_i2c_transfer(chip, buffer, transfer, read, - len <= transfer)) - return 1; + is_last)) + return 2; buffer += transfer; - addr += transfer; len -= transfer; } return 0; } - static void ihs_i2c_init(struct i2c_adapter *adap, int speed, int slaveaddr) { #ifdef CONFIG_SYS_I2C_INIT_BOARD @@ -173,7 +174,7 @@ static int ihs_i2c_probe(struct i2c_adapter *adap, uchar chip) { uchar buffer[2]; - if (ihs_i2c_transfer(chip, buffer, 0, true, true)) + if (ihs_i2c_transfer(chip, buffer, 0, I2COP_READ, true)) return 1; return 0; @@ -182,13 +183,23 @@ static int ihs_i2c_probe(struct i2c_adapter *adap, uchar chip) static int ihs_i2c_read(struct i2c_adapter *adap, uchar chip, uint addr, int alen, uchar *buffer, int len) { - return ihs_i2c_access(adap, chip, addr, alen, buffer, len, true); + u8 addr_bytes[4]; + + put_unaligned_le32(addr, addr_bytes); + + return ihs_i2c_access(adap, chip, addr_bytes, alen, buffer, len, + I2COP_READ); } static int ihs_i2c_write(struct i2c_adapter *adap, uchar chip, uint addr, int alen, uchar *buffer, int len) { - return ihs_i2c_access(adap, chip, addr, alen, buffer, len, false); + u8 addr_bytes[4]; + + put_unaligned_le32(addr, addr_bytes); + + return ihs_i2c_access(adap, chip, addr_bytes, alen, buffer, len, + I2COP_WRITE); } static unsigned int ihs_i2c_set_bus_speed(struct i2c_adapter *adap, -- 2.39.5