On Mon, Jan 23, 2023 at 01:51:36PM +0100, Hans de Goede wrote: > The following drivers under drivers/media/i2c: ov08x40.c, ov13858.c, > ov13b10.c, ov2680.c, ov2685.c, ov2740.c, ov4689.c, ov5670.c, > ov5675.c, ov5695.c, ov8856.c, ov9282.c and ov9734.c, > > as well as various "atomisp" sensor drivers in drivers/staging, *all* > use register access helpers with the following function prototypes: > > int ovxxxx_read_reg(struct ovxxxx_dev *sensor, u16 reg, > unsigned int len, u32 *val); > > int ovxxxx_write_reg(struct ovxxxx_dev *sensor, u16 reg, > unsigned int len, u32 val); > > To read/write registers on Omnivision OVxxxx image sensors wich expect > a 16 bit register address in big-endian format and which have 1-3 byte > wide registers, in big-endian format (for the higher width registers). > > Add a new ovxxxx_16bit_addr_reg_helpers.h header file with static inline > versions of these register access helpers, so that this code duplication > can be removed. ... > +#include <asm/unaligned.h> Usually we put linux/* followed by asm/*. > +#include <linux/dev_printk.h> > +#include <linux/i2c.h> > + > +static inline int ovxxxx_read_reg(struct i2c_client *client, u16 reg, > + unsigned int len, u32 *val) > +{ > + struct i2c_msg msgs[2]; > + u8 addr_buf[2] = { reg >> 8, reg & 0xff }; Let's use unaligned.h or byteorder/generic.h? __be16 addr_buf = cpu_to_be16(reg); > + u8 data_buf[4] = { 0, }; 0, is not needed. > + int ret; > + > + if (len > 4) > + return -EINVAL; > + > + msgs[0].addr = client->addr; > + msgs[0].flags = 0; > + msgs[0].len = ARRAY_SIZE(addr_buf); > + msgs[0].buf = addr_buf; msgs[0].buf = &addr_buf; > + msgs[1].addr = client->addr; > + msgs[1].flags = I2C_M_RD; > + msgs[1].len = len; > + msgs[1].buf = &data_buf[4 - len]; This trick I don't like. Can we have like other driver have it, i.e. switch case for the possible length and explicit usage of the endian conversion calls? > + ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs)); > + if (ret != ARRAY_SIZE(msgs)) { > + dev_err(&client->dev, "read error: reg=0x%4x: %d\n", reg, ret); > + return -EIO; > + } > + > + *val = get_unaligned_be32(data_buf); > + > + return 0; > +} > + > +#define ovxxxx_read_reg8(s, r, v) ovxxxx_read_reg(s, r, 1, v) > +#define ovxxxx_read_reg16(s, r, v) ovxxxx_read_reg(s, r, 2, v) > +#define ovxxxx_read_reg24(s, r, v) ovxxxx_read_reg(s, r, 3, v) > + > +static inline int ovxxxx_write_reg(struct i2c_client *client, u16 reg, > + unsigned int len, u32 val) > +{ > + u8 buf[6]; > + int ret; > + > + if (len > 4) > + return -EINVAL; > + put_unaligned_be16(reg, buf); > + put_unaligned_be32(val << (8 * (4 - len)), buf + 2); Something similar here? > + ret = i2c_master_send(client, buf, len + 2); > + if (ret != len + 2) { > + dev_err(&client->dev, "write error: reg=0x%4x: %d\n", reg, ret); > + return -EIO; > + } > + > + return 0; > +} > + > +#define ovxxxx_write_reg8(s, r, v) ovxxxx_write_reg(s, r, 1, v) > +#define ovxxxx_write_reg16(s, r, v) ovxxxx_write_reg(s, r, 2, v) > +#define ovxxxx_write_reg24(s, r, v) ovxxxx_write_reg(s, r, 3, v) > + > +static inline int ovxxxx_mod_reg(struct i2c_client *client, u16 reg, u8 mask, u8 val) > +{ > + u32 readval; > + int ret; > + > + ret = ovxxxx_read_reg8(client, reg, &readval); > + if (ret < 0) > + return ret; > + readval &= ~mask; > + val &= mask; > + val |= readval; Usual pattern: val = (readval & ~mask) | (val & mask); > + return ovxxxx_write_reg8(client, reg, val); > +} -- With Best Regards, Andy Shevchenko