[PATCH net-next 11/37] can: rcar_canfd: Allow the CAN FD clock to be sourced from fck
flat view
COOLING5d
REVIEWED: 6 (6M)
From: Marc Kleine-Budde <mkl@pengutronix.de>
Date: 2026-10-09 13:43:37
Also in:
linux-can
Subsystem:
can network drivers, the rest · Maintainers:
Marc Kleine-Budde, Vincent Mailhol, Linus Torvalds
1 review trailer.
From: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> On the Renesas RZ/G3S, the CAN FD clock can be sourced either from fck (the peripheral clock) or from an external clock (can_clk). When fck is used, it is divided internally by the CAN FD controller. Adjust the existing canfd clock handling code to support the RZ/G3S CAN. The existing struct rcar_canfd_hw_info instances were updated to address the request in the Link discussion. Link: https://lore.kernel.org/all/1d9719e3-10ff-4cd8-b729-55fea93c37ce@wanadoo.fr (local) Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> Link: https://patch.msgid.link/20260902141544.565763-4-claudiu.beznea+renesas@tuxon.dev (local) Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> --- drivers/net/can/rcar/rcar_canfd.c | 23 ++++++++++++++++++----- 1 file changed, 18 insertions(+), 5 deletions(-)
diff --git a/drivers/net/can/rcar/rcar_canfd.c b/drivers/net/can/rcar/rcar_canfd.c
index b7c4fe3477ac..f9173774387f 100644
--- a/drivers/net/can/rcar/rcar_canfd.c
+++ b/drivers/net/can/rcar/rcar_canfd.c@@ -444,6 +444,7 @@ struct rcar_canfd_hw_info { unsigned ch_interface_mode:1; /* Has channel interface mode */ unsigned shared_can_regs:1; /* Has shared classical can registers */ unsigned external_clk:1; /* Has external clock */ + unsigned fcan_pclk:1; /* Has fcan sourced from pclk. */ }; /* Channel priv data */
@@ -617,6 +618,7 @@ static const struct rcar_canfd_hw_info rcar_gen3_hw_info = { .ch_interface_mode = 0, .shared_can_regs = 0, .external_clk = 1, + .fcan_pclk = 0, }; static const struct rcar_canfd_hw_info rcar_gen4_hw_info = {
@@ -634,6 +636,7 @@ static const struct rcar_canfd_hw_info rcar_gen4_hw_info = { .ch_interface_mode = 1, .shared_can_regs = 1, .external_clk = 1, + .fcan_pclk = 0, }; static const struct rcar_canfd_hw_info rzg2l_hw_info = {
@@ -651,6 +654,7 @@ static const struct rcar_canfd_hw_info rzg2l_hw_info = { .ch_interface_mode = 0, .shared_can_regs = 0, .external_clk = 1, + .fcan_pclk = 0, }; static const struct rcar_canfd_hw_info r9a09g047_hw_info = {
@@ -668,6 +672,7 @@ static const struct rcar_canfd_hw_info r9a09g047_hw_info = { .ch_interface_mode = 1, .shared_can_regs = 1, .external_clk = 0, + .fcan_pclk = 0, }; static const struct rcar_canfd_hw_info r9a09g077_hw_info = {
@@ -685,6 +690,7 @@ static const struct rcar_canfd_hw_info r9a09g077_hw_info = { .ch_interface_mode = 1, .shared_can_regs = 1, .external_clk = 1, + .fcan_pclk = 0, }; /* Helper functions */
@@ -2190,13 +2196,20 @@ static int rcar_canfd_probe(struct platform_device *pdev) */ gpriv->can_clk = devm_clk_get(dev, "can_clk"); if (IS_ERR(gpriv->can_clk) || (clk_get_rate(gpriv->can_clk) == 0)) { - gpriv->can_clk = devm_clk_get(dev, "canfd"); - if (IS_ERR(gpriv->can_clk)) - return dev_err_probe(dev, PTR_ERR(gpriv->can_clk), - "cannot get canfd clock\n"); + if (info->fcan_pclk) { + fcan_freq = clk_get_rate(gpriv->clkp); + gpriv->can_clk = NULL; + } else { + gpriv->can_clk = devm_clk_get(dev, "canfd"); + if (IS_ERR(gpriv->can_clk)) + return dev_err_probe(dev, PTR_ERR(gpriv->can_clk), + "cannot get canfd clock\n"); + + fcan_freq = clk_get_rate(gpriv->can_clk); + } /* CANFD clock may be further divided within the IP */ - fcan_freq = clk_get_rate(gpriv->can_clk) / info->postdiv; + fcan_freq /= info->postdiv; } else { fcan_freq = clk_get_rate(gpriv->can_clk); gpriv->extclk = gpriv->info->external_clk;
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2.53.0