Messages in this thread | | | Date | Thu, 18 Jun 2020 11:15:11 +0100 | From | Lee Jones <> | Subject | Re: [PATCH v3 1/2] mfd: da9063: Fix revision handling to correctly select reg tables |
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On Fri, 17 Apr 2020, Adam Thomson wrote:
> The current implementation performs checking in the i2c_probe() > function of the variant_code but does this immediately after the > containing struct has been initialised as all zero. This means the > check for variant code will always default to using the BB tables > and will never select AD. The variant code is subsequently set > by device_init() and later used by the RTC so really it's a little > fortunate this mismatch works. > > This update adds raw I2C read access functionality to read the chip > and variant/revision information (common to all revisions) so that > it can subsequently correctly choose the proper regmap tables for > real initialisation. > > Signed-off-by: Adam Thomson <Adam.Thomson.Opensource@diasemi.com> > --- > drivers/mfd/da9063-core.c | 31 ------ > drivers/mfd/da9063-i2c.c | 184 +++++++++++++++++++++++++++++++---- > include/linux/mfd/da9063/registers.h | 15 ++- > 3 files changed, 177 insertions(+), 53 deletions(-)
[...]
> + * Raw I2C access required for just accessing chip and variant info before we > + * know which device is present. The info read from the device using this > + * approach is then used to select the correct regmap tables. > + */ > + > +#define DA9063_REG_PAGE_SIZE 0x100 > +#define DA9063_REG_PAGED_ADDR_MASK 0xFF > + > +enum da9063_page_sel_buf_fmt { > + DA9063_PAGE_SEL_BUF_PAGE_REG = 0, > + DA9063_PAGE_SEL_BUF_PAGE_VAL, > + DA9063_PAGE_SEL_BUF_SIZE, > +}; > + > +enum da9063_paged_read_msgs { > + DA9063_PAGED_READ_MSG_PAGE_SEL = 0, > + DA9063_PAGED_READ_MSG_REG_SEL, > + DA9063_PAGED_READ_MSG_DATA, > + DA9063_PAGED_READ_MSG_CNT, > +}; > + > +static int da9063_i2c_blockreg_read(struct i2c_client *client, u16 addr, > + u8 *buf, int count) > +{ > + struct i2c_msg xfer[DA9063_PAGED_READ_MSG_CNT]; > + u8 page_sel_buf[DA9063_PAGE_SEL_BUF_SIZE]; > + u8 page_num, paged_addr; > + int ret; > + > + /* Determine page info based on register address */ > + page_num = (addr / DA9063_REG_PAGE_SIZE); > + if (page_num > 1) { > + dev_err(&client->dev, "Invalid register address provided\n"); > + return -EINVAL; > + } > + > + paged_addr = (addr % DA9063_REG_PAGE_SIZE) & DA9063_REG_PAGED_ADDR_MASK; > + page_sel_buf[DA9063_PAGE_SEL_BUF_PAGE_REG] = DA9063_REG_PAGE_CON; > + page_sel_buf[DA9063_PAGE_SEL_BUF_PAGE_VAL] = > + (page_num << DA9063_I2C_PAGE_SEL_SHIFT) & DA9063_REG_PAGE_MASK; > + > + /* Write reg address, page selection */ > + xfer[DA9063_PAGED_READ_MSG_PAGE_SEL].addr = client->addr; > + xfer[DA9063_PAGED_READ_MSG_PAGE_SEL].flags = 0; > + xfer[DA9063_PAGED_READ_MSG_PAGE_SEL].len = DA9063_PAGE_SEL_BUF_SIZE; > + xfer[DA9063_PAGED_READ_MSG_PAGE_SEL].buf = page_sel_buf; > + > + /* Select register address */ > + xfer[DA9063_PAGED_READ_MSG_REG_SEL].addr = client->addr; > + xfer[DA9063_PAGED_READ_MSG_REG_SEL].flags = 0; > + xfer[DA9063_PAGED_READ_MSG_REG_SEL].len = sizeof(paged_addr); > + xfer[DA9063_PAGED_READ_MSG_REG_SEL].buf = &paged_addr; > + > + /* Read data */ > + xfer[DA9063_PAGED_READ_MSG_DATA].addr = client->addr; > + xfer[DA9063_PAGED_READ_MSG_DATA].flags = I2C_M_RD; > + xfer[DA9063_PAGED_READ_MSG_DATA].len = count; > + xfer[DA9063_PAGED_READ_MSG_DATA].buf = buf; > + > + ret = i2c_transfer(client->adapter, xfer, DA9063_PAGED_READ_MSG_CNT); > + if (ret < 0) { > + dev_err(&client->dev, "Paged block read failed: %d\n", ret); > + return ret; > + } > + > + if (ret != DA9063_PAGED_READ_MSG_CNT) { > + dev_err(&client->dev, "Paged block read failed to complete\n"); > + return -EIO; > + } > + > + return 0; > +}
Rather than open coding this, does it make sense to register a small (temporary?) Device ID Regmap to read from?
-- Lee Jones [李琼斯] Senior Technical Lead - Developer Services Linaro.org │ Open source software for Arm SoCs Follow Linaro: Facebook | Twitter | Blog
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