| Message ID | 20240823141917.692336-3-Shyam-sundar.S-k@amd.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Introduce initial AMD I3C HCI driver support | expand |
Hi On 8/23/24 5:19 PM, Shyam Sundar S K wrote: > The HC_CONTROL_PIO_MODE bit was introduced in the HC_CONTROL register > starting from version 1.1. Therefore, checking the HC_CONTROL_PIO_MODE bit > on hardware that adheres to older specification revisions (i.e., versions > earlier than 1.1) is incorrect. To address this, add an additional check > to read the HCI version before attempting to read the HC_CONTROL_PIO_MODE > status. > > Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com> > --- > drivers/i3c/master/mipi-i3c-hci/core.c | 9 ++++++--- > 1 file changed, 6 insertions(+), 3 deletions(-) > > diff --git a/drivers/i3c/master/mipi-i3c-hci/core.c b/drivers/i3c/master/mipi-i3c-hci/core.c > index 07de1cecfa30..42d2362d072b 100644 > --- a/drivers/i3c/master/mipi-i3c-hci/core.c > +++ b/drivers/i3c/master/mipi-i3c-hci/core.c > @@ -630,8 +630,8 @@ static irqreturn_t i3c_hci_irq_handler(int irq, void *dev_id) > > static int i3c_hci_init(struct i3c_hci *hci) > { > + bool size_in_dwords, pio_mode_support; > u32 regval, offset; > - bool size_in_dwords; > int ret; > > /* Validate HCI hardware version */ > @@ -753,10 +753,13 @@ static int i3c_hci_init(struct i3c_hci *hci) > return -EINVAL; > } > > + pio_mode_support = hci->version_major > 1 || > + (hci->version_major == 1 && hci->version_minor > 0) ? true : false; > + I'd rename this as mode_selector etc. since I've understood PIO mode is possible in earlier version(s) too. Also latter part of statement "? true : false" is needless.
diff --git a/drivers/i3c/master/mipi-i3c-hci/core.c b/drivers/i3c/master/mipi-i3c-hci/core.c index 07de1cecfa30..42d2362d072b 100644 --- a/drivers/i3c/master/mipi-i3c-hci/core.c +++ b/drivers/i3c/master/mipi-i3c-hci/core.c @@ -630,8 +630,8 @@ static irqreturn_t i3c_hci_irq_handler(int irq, void *dev_id) static int i3c_hci_init(struct i3c_hci *hci) { + bool size_in_dwords, pio_mode_support; u32 regval, offset; - bool size_in_dwords; int ret; /* Validate HCI hardware version */ @@ -753,10 +753,13 @@ static int i3c_hci_init(struct i3c_hci *hci) return -EINVAL; } + pio_mode_support = hci->version_major > 1 || + (hci->version_major == 1 && hci->version_minor > 0) ? true : false; + /* Try activating DMA operations first */ if (hci->RHS_regs) { reg_clear(HC_CONTROL, HC_CONTROL_PIO_MODE); - if (reg_read(HC_CONTROL) & HC_CONTROL_PIO_MODE) { + if (pio_mode_support && (reg_read(HC_CONTROL) & HC_CONTROL_PIO_MODE)) { dev_err(&hci->master.dev, "PIO mode is stuck\n"); ret = -EIO; } else { @@ -768,7 +771,7 @@ static int i3c_hci_init(struct i3c_hci *hci) /* If no DMA, try PIO */ if (!hci->io && hci->PIO_regs) { reg_set(HC_CONTROL, HC_CONTROL_PIO_MODE); - if (!(reg_read(HC_CONTROL) & HC_CONTROL_PIO_MODE)) { + if (pio_mode_support && !(reg_read(HC_CONTROL) & HC_CONTROL_PIO_MODE)) { dev_err(&hci->master.dev, "DMA mode is stuck\n"); ret = -EIO; } else {
The HC_CONTROL_PIO_MODE bit was introduced in the HC_CONTROL register starting from version 1.1. Therefore, checking the HC_CONTROL_PIO_MODE bit on hardware that adheres to older specification revisions (i.e., versions earlier than 1.1) is incorrect. To address this, add an additional check to read the HCI version before attempting to read the HC_CONTROL_PIO_MODE status. Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com> --- drivers/i3c/master/mipi-i3c-hci/core.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-)