From: Jia Wang <wangjia@ultrarisc.com>
To: "Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>,
"Andy Shevchenko" <andriy.shevchenko@linux.intel.com>,
"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
"Jiri Slaby" <jirislaby@kernel.org>,
"Paul Walmsley" <pjw@kernel.org>,
"Palmer Dabbelt" <palmer@dabbelt.com>,
"Albert Ou" <aou@eecs.berkeley.edu>,
"Alexandre Ghiti" <alex@ghiti.fr>,
"Rob Herring" <robh@kernel.org>,
"Krzysztof Kozlowski" <krzk+dt@kernel.org>,
"Conor Dooley" <conor+dt@kernel.org>
Cc: linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org,
linux-riscv@lists.infradead.org, devicetree@vger.kernel.org,
Jia Wang <wangjia@ultrarisc.com>
Subject: [PATCH v7 4/4] serial: 8250_dw: Use a fixed CPR value for UltraRISC DP1000 UART
Date: Wed, 29 Apr 2026 17:13:28 +0800 [thread overview]
Message-ID: <20260429-ultrarisc-serial-v7-4-e475cce9e274@ultrarisc.com> (raw)
In-Reply-To: <20260429-ultrarisc-serial-v7-0-e475cce9e274@ultrarisc.com>
The UltraRISC DP1000 UART does not provide the standard CPR register used
by 8250_dw to discover port capabilities.
Provide a fixed CPR value for the DP1000-specific compatible so the
driver can configure the port correctly.
Signed-off-by: Jia Wang <wangjia@ultrarisc.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
drivers/tty/serial/8250/8250_dw.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c
index 480f82d89856..55e40c10f46a 100644
--- a/drivers/tty/serial/8250/8250_dw.c
+++ b/drivers/tty/serial/8250/8250_dw.c
@@ -959,6 +959,15 @@ static const struct dw8250_platform_data dw8250_intc10ee = {
.quirks = DW_UART_QUIRK_IER_KICK,
};
+static const struct dw8250_platform_data dw8250_ultrarisc_dp1000_data = {
+ .usr_reg = DW_UART_USR,
+ .cpr_value = FIELD_PREP_CONST(DW_UART_CPR_ABP_DATA_WIDTH, 2) |
+ DW_UART_CPR_THRE_MODE |
+ DW_UART_CPR_DMA_EXTRA |
+ DW_UART_CPR_FIFO_MODE_FROM_SIZE(32),
+ .quirks = DW_UART_QUIRK_CPR_VALUE,
+};
+
static const struct of_device_id dw8250_of_match[] = {
{ .compatible = "snps,dw-apb-uart", .data = &dw8250_dw_apb },
{ .compatible = "cavium,octeon-3860-uart", .data = &dw8250_octeon_3860_data },
@@ -966,6 +975,7 @@ static const struct of_device_id dw8250_of_match[] = {
{ .compatible = "renesas,rzn1-uart", .data = &dw8250_renesas_rzn1_data },
{ .compatible = "sophgo,sg2044-uart", .data = &dw8250_skip_set_rate_data },
{ .compatible = "starfive,jh7100-uart", .data = &dw8250_skip_set_rate_data },
+ { .compatible = "ultrarisc,dp1000-uart", .data = &dw8250_ultrarisc_dp1000_data },
{ /* Sentinel */ }
};
MODULE_DEVICE_TABLE(of, dw8250_of_match);
--
2.34.1
next prev parent reply other threads:[~2026-04-29 9:13 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-04-29 9:13 [PATCH v7 0/4] serial: 8250_dw: Add support for UltraRISC DP1000 UART Jia Wang
2026-04-29 9:13 ` [PATCH v7 1/4] serial: 8250_dwlib: move DesignWare register definitions to header Jia Wang
2026-04-29 9:13 ` [PATCH v7 2/4] serial: 8250_dw: build Renesas RZN1 CPR value from DW_UART_CPR_* definitions Jia Wang
2026-04-29 10:45 ` Andy Shevchenko
2026-04-29 10:48 ` Ilpo Järvinen
2026-04-29 9:13 ` [PATCH v7 3/4] dt-bindings: serial: snps-dw-apb-uart: Add UltraRISC DP1000 UART Jia Wang
2026-04-29 9:13 ` Jia Wang [this message]
2026-04-29 10:55 ` [PATCH v7 4/4] serial: 8250_dw: Use a fixed CPR value for " Ilpo Järvinen
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